Article

Low-Grade Fibromyxoid Sarcoma: A Review and Update

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Abstract

The low-grade fibromyxoid sarcoma (LGFMS), first described by Dr. Harry Evans in 1987, is a rare, enigmatic soft tissue sarcoma. Characterized by deceptively bland histologic features, LGFMS was thought until recently to have a paradoxically aggressive course. This review article summarizes the current state of knowledge about LGFMS and its collagen rosette–containing variant, the hyalinizing spindle cell tumor with giant rosettes. The differential diagnosis of LGFMS also is discussed.

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... Fewer than 350 cases are reported in literature. The majority of these were initially misdiagnosed as benign entities, such as a fibroma or fibromatosis, and later presented with metastases [2]. Hyalinizing spindle cell tumor with giant rosettes (HSTGR) is now considered to be part of the histological spectrum of low-grade fibromyxoid sarcoma (LGFMS) [3]. ...
... Studies have shown shared morphologic features and common cytogenetic alterations between these two tumors [3][4][5]. There is no sex predilection for either, and young adults are predominantly affected [2,4]. ...
... Recent studies show that superficial LGFMS may occur more frequently than previously believed and predominately affect the pediatric population [3]. This entity is now considered a grade 1 sarcoma with potential for local recurrences and distant metastases [2]. Here, we present a case of HSTGR presenting as a superficial, polypoid mass arising from the external auditory meatus. ...
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Low-grade fibromyxoid sarcoma (LGFMS) is an enigmatic soft tissue tumor. It frequently presents as a deeply seated mass in the proximal extremities and trunk. Superficial LGFMSs of the head and neck are exceedingly rare. Hyalinizing spindle cell tumor with giant rosettes (HSTGR) is an entity considered to be on the histologic spectrum of LGFMS. We present a case of a 44-year-old female who presented with a superficial, polypoid mass of the external auditory meatus. Microscopic examination revealed the classic histologic features of HSTGR. To our knowledge, this case is the first described at this extremely unusual location. Identification and reporting of such unusual cases is important to understand and compare the behavior of superficial LGFMS to that of the more common deeply seated tumors.
Article
Low-grade fibromyxoid sarcoma (LGFMS) is a rare sarcoma subtype. The most common tumor locations are the deep soft tissue of extremities or trunks. We report a rare case of recurrent LGFMS in the inguinal region involving the scrotum and both testicles. A 38-year-old male patient reported a history of multiple nodular lesions in the left inguinal region accompanied by local inflammation. The patient was submitted for local resection of the lesion at our institution, with histopathological diagnosis of LGFMS. He missed his follow-up, returning with a large bulge in the left inguinal region involving the scrotum with signs of tissue necrosis and local purulent discharge. Surgical exploration was performed and the patient underwent tumor resection in the left inguinal region and the entire scrotum, with bilateral orchiectomy, with the margins enlarged to the right inguinal region and proximal surface of the penis. Local reconstruction was performed with a left fascia lata tensor muscle flap and ipsilateral thigh coverage using partial skin graft. On microscopic examination, the tumor showed spindle cells arranged in bundles, with abundant collagen and myxoid stroma with interspersed prominent vessels. The immunohistochemical study carried out showed immunoreactivity with Ki67 (<5%), immunonegativity with desmin and S100, confirming the diagnosis of LGFMS. Postoperative recovery was good and no recurrence was seen after two years. The patient is in good health, realizing multidisciplinary outpatient follow-up and performing continuous testosterone replacement. Surgical resection with negative margins for localized disease remains the standard treatment for LGFMS.
Article
Low-grade fibromyxoid sarcoma (LGFMS) is a rare sarcoma subtype. The most common tumor locations are the deep soft tissue of extremities or trunks. We report a rare case of recurrent LGFMS in the inguinal region involving the scrotum and both testicles. A 38-year-old male patient reported a history of multiple nodular lesions in the left inguinal region accompanied by local inflammation. The patient was submitted for local resection of the lesion at our institution, with histopathological diagnosis of LGFMS. He missed his follow-up, returning with a large bulge in the left inguinal region involving the scrotum with signs of tissue necrosis and local purulent discharge. Surgical exploration was performed and the patient underwent tumor resection in the left inguinal region and the entire scrotum, with bilateral orchiectomy, with the margins enlarged to the right inguinal region and proximal surface of the penis. Local reconstruction was performed with a left fascia lata tensor muscle flap and ipsilateral thigh coverage using partial skin graft. On microscopic examination, the tumor showed spindle cells arranged in bundles, with abundant collagen and myxoid stroma with interspersed prominent vessels. The immunohistochemical study carried out showed immunoreactivity with Ki67 (<5%), immunonegativity with desmin and S100, confirming the diagnosis of LGFMS. Postoperative recovery was good and no recurrence was seen after two years. The patient is in good health, realizing multidisciplinary outpatient follow-up and performing continuous testosterone replacement. Surgical resection with negative margins for localized disease remains the standard treatment for LGFMS.
Article
Low-grade fibromyxoid sarcoma (LGFMS) is an uncommon neoplasm with bland morphology and an indolent clinical course, although metastases may develop in approximately 5-10% of the cases. The diagnosis of LGFMS can be difficult to render from fine needle aspiration cytology (FNAC) alone because of morphological overlap with other spindle cell and myxoid lesions. To determine cytological criteria for LGFMS by reviewing FNAC aspirates in eight cases and to compare the findings with those in subsequent histological sections. FNAC slides were reviewed from eight patients with subsequently excised tumours diagnosed as LGFMS. Of these patients, six also had core needle biopsies (CNB). Cytogenetic and/or molecular analysis was carried on all tumours. The patients were six men and two women ranging in age from 26 to 78 years. Tumours arose in the deep soft tissues of the thigh (n = 5), shoulder girdle (n = 1) or upper arm (n = 1) and one in the subcutaneous tissue of the abdominal wall. Cytological features included clusters of bland spindle and round/polygonal cells embedded in a collagenous and myxoid matrix along with dissociated, uniform or slightly/moderately pleomorphic spindle cells, bare nuclei and fragments of collagen and myxoid tissue in varying proportions. Unequivocal sarcoma was diagnosed in two aspirates, but mitoses were absent in all cases. In three cases, the diagnosis was inconclusive with regard to benignity or malignancy, while three were erroneously diagnosed as benign spindle cell lesions. Although the diagnosis was suggested on three of six CNB, these presented similar diagnostic problems. There were no cytomorphological findings in FNAC to allow for a clear cut separation of LGFMS from other spindle cell or myxoid lesions, but high-grade sarcoma could be excluded. Surgical (incisional or excisional) biopsy or, alternatively, examination of RT-PCR for the FUS/CREB3L or FUS/CREB3L1 fusion transcripts may be necessary to obtain a correct diagnosis.
Article
Context.—Hyalinizing spindle cell tumor with giant rosettes is a recently described biphasic neoplasm of soft tissues that shares mesenchymal and neuroendocrine features. Its morphologic structure is distinctive, with the presence of hyalinized paucicellular foci that are termed rosettes. The cells around the latter display positive immunoreactivity for neuroendocrine markers. The small number of cases described to date indicates that they tend to be localized in the extremities. Objective.—To describe the clinicopathologic features of 2 unusual cases of hyalinizing spindle cell tumor with giant rosettes. Methods and Results.—One tumor was located in the prestyloid parapharyngeal space and the second in the left thigh. Both tumors were well circumscribed and surrounded by a thin capsulelike fibrous band without infiltrating projections. The rosettes were embedded in a spindle cell proliferation. Immunohistochemical stains showed positive results for S100 protein, synaptophysin, CD57, protein gene product 9.5, and neuron-specific enolase exclusively in the cells palisading the rosettes. These markers were negative in the spindle cell portions of the tumor. The latter were immunoreactive for factor XIIIa, vimentin, HAM56, collagen IV, and CD68. Vimentin was the only marker shared by the rosette-forming cells and the spindle cells. Ultrastructurally, the rosette-forming cells contained neurosecretory granules. This study describes the first cytogenetic analysis in this type of tumor revealing 2 cell lines, both containing a balanced translocation between chromosomes 7 and 16. Follow-up of the patients at 16 and 8 months did not disclose evidence of recurrence. Conclusions.—These 2 new cases increase the awareness of hyalinizing spindle cell tumor with giant rosettes and demonstrate that it is a spindle cell neoplasm of unique cytogenetic rearrangements composed of dendritic, histiocytic, and fibroblastic cells admixed with cells that have neuroendocrine differentiation.
Article
Low-grade fibromyxoid sarcoma (LGFMS) is a rare sarcoma characterized by bland histologic features and a paradoxically aggressive clinical course. The hyalinizing spindle cell tumor with giant rosettes (HSCT) is a closely related tumor characterized by the presence of giant collagen rosettes. Only a single example of a metastasizing HSCT has been reported. A small subset of both LGFMS and HSCT display areas of increased cellularity and atypia which qualify as intermediate-to high-grade sarcoma; the significance of these features has not been definitively assessed. We present the clinicopathologic features of 77 cases of LGFMS and HSCT to determine the degree of overlap of these two lesions, their biologic behavior, and the significance of the occasional presence of intermediate-to high-grade sarcoma within both. The patients (33 female, 40 male) ranged from 3 to 78 years of age (median, 34 yrs). Fourteen cases occurred in patients less than 18 years of age. The tumors measured from 1 to 23 cm (median, 4.5 cm) and occurred predominantly in the trunk and lower extremities in both the deep (66 cases) and superficial (7 cases) soft tissues. In 15 cases, the tumor was present >1 year before diagnosis. All tumors showed predominantly the typical hypocellularity and bland cytologic features of typical LGFMS; however, areas of hypercellularity and nuclear enlargement and hyperchromatism were identified in 12 of 73 (16%) and 7 of 73 (10%), respectively. Necrosis and mitotic activity >5/50 high-powered fields (HPF) were present in 6 of 73 (8%) and 5 of 73 (7%), respectively. Epithelioid areas were present in 33 of 73 (45%) and rosettes in 22 of 73 (30%). Follow up (54 cases; range, 2–192 mos; median, 24 mos; mean, 38 mos) showed 5 recurrences, 3 metastases, and 1 death. The diagnosis of LGFMS or HSCT was made prospectively in 51 patients; none had metastatic disease. Two of the metastatic tumors were LGFMS and one was a HSCT. LGFMS may occur more often in the pediatric population and show a much wider histologic spectrum than previously thought. A significant number of LGFMS possess inconspicuous collagen rosettes characteristic of HSCT, indicating that these two tumors are ends of a common spectrum rather than distinct entities. HSCT, like LGFMS, are low-grade sarcomas with metastatic potential. The presence of focal areas of intermediate-to high-grade sarcoma does not portend a worse outcome in the short term. The better prognosis reflected in this study compared with previous ones might reflect the fact that all were initially diagnosed as sarcomas and treated with aggressive surgery. The fact that the only three patients to develop metastatic disease were patients whose LGFMS or HSCT was identified retrospectively supports this concept.
Article
We report the light microscopic, ultrastructural appearance and immunohistochemical staining profile of three distinctive soft-tissue tumors recently designated hyalinizing spindle cell tumor with giant rosettes. The tumors occurred in two men, 41 and 54 years old, and one woman, 62 years old. Two tumors arose in the lower extremities and one in the upper arm. Two tumors were resected and measured 3 and 13.2 cm in greatest diameter; a biopsy only was done of the third tumor. Grossly, the tumors had a tan, pink, or white cut surface. The largest tumor exhibited central cystic change. Microscopically, they all displayed similar features and were composed of fibromyxoid regions, with areas of hyalinization in two tumors and focal ossification in one tumor. Scattered throughout each of the tumors were rosette-like structures in which neoplastic cells were arranged around a central collagenous core. Ultrastructurally, the neoplastic cells demonstrated the features of fibroblasts. In all tumors, there was abundant extracellular collagen fibers and in one there were large aggregates of amorphous extracellular external lamina-like material. The center of the rosette-like structures was composed of banded collagen fibers and the cells at the periphery of the rosettes had ultrastructural features similar to the neoplastic spindle cells located elsewhere in the tumor. Immunohistochemically, the tumor cells stained for vimentin. There was focal staining of the widely distributed spindle cells and cells that formed the rosettes for Leu-7, S-100 protein, and CD34. In one tumor, there was faint diffuse staining of the spindle cells for neuron-specific enolase. One tumor (with the amorphous extracellular material) stained for type IV collagen. There was no staining for desmin, muscle actin, smooth muscle actin, keratin, or epithelial membrane antigen. These results demonstrate that hyalinizing spindle cell tumor with giant rosettes is composed of fibroblasts. We did not demonstrate any ultrastructural or immunohistochemical differences between the spindle cells that comprised the majority of the mass and those that surrounded the rosette-like structures. There was no ultrastructural evidence of neural differentiation to explain the focal S-100 protein and Leu-7 staining of the tumor cells.
Article
Seven cases of desmoplastic fibroblastoma, a distinctive fibrous soft-tissue tumor, are presented. The patients, four men and three women, ranged in age from 25 to 83 years (median 57 years). The tumors were located in the neck (two cases), the upper arm, the forearm, the shoulder, the lateral thigh, and the dorsum of the foot (one case each). Three neoplasms were intramuscular, and four were subcutaneous (two of the latter were directly on top of muscle). Maximum tumor dimension varied from 1.8 cm to 9 cm (median 3.2 cm). Grossly, the lesions were well circumscribed, firm, and white to gray to tan on cut section. Microscopically, they were composed of medium-sized to large "reactive appearing" spindled to stellate fibroblasts sparsely distributed in a fibromyxoid to densely fibrous background: mitotic figures were very rare or absent, tumor necrosis was not seen, and vascularity was low. The tumor border was generally well delimited, although interdigitation with adjacent muscle or fat was present in areas in some cases. Follow-up ranging from 15 months to 46 months (median 28 months) after excision was available on five patients. No recurrences were observed.
Article
Most malignant peripheral nerve sheath tumors (MPNST) are schwannian in nature. The pathologic features of MPNST with perineurial cell differentiation remain to be characterized. To determine the clinicopathologic, immunohistochemical, and ultrastructural characteristics of perineurial MPNST, 121 MPNST from the Mayo Clinic Tissue Registry were examined. Of these 23 spindle cell tumors with long processes disposed in whorls or storiform patterns, features typical of perineurioma, were studied. On the basis of immunohistochemistry (epithelial membrane antigen+/S-100-), 5 perineurial MPNST were identified among 23 tumors selected. These and two previously characterized perineurial MPNST are the subject of this study. None of seven tumors was associated with NF-1. Patients included five males and two females ranging in age from 11 to 83 years (mean, 45.7 years). The tumors measured 1.5 to 30 cm (mean, 9.1 cm) and arose in the extremities (two), trunk (two), face (one), mediastinum (one), and retroperitoneum (one). Only one tumor was nerve associated (phrenic nerve). All tumors were surgically removed. No encapsulation or neurofibroma components were noted. Necrosis was seen in three lesions. Four tumors were classified as high-grade malignant and three as low grade. Mitotic indices varied from 1 to 85/10 high-power fields (median, 16). Immunoreactivities included epithelial membrane antigen (100%), vimentin (100%), Leu-7 (57%), and CD34 (14%). Stains for S-100 protein, muscle markers, and cytokeratin were nonreactive. Ultrastructurally, perineurial-like cells were noted in three tumors and cells intermediate between perineurial and Schwann cells in one. Four tumors recurred and two metastasized; no deaths of disease were noted at follow-ups of 28 to 98 months (mean, 66.9). In conclusion, 4% of MPNST show perineurial cell differentiation. An NF-1 association has yet to be described. Nerve involvement is infrequent. Their immunophenotype (epithelial membrane antigen+/S-100-) frequently indicates ultrastructural perineurial differentiation. The prognosis of perineural MPNST appears to be more favorable than that of conventional MPNST.
Article
We report the findings of 19 cases of a previously undescribed spindle cell tumor of soft tissues that resembles a low-grade fibromyxoid sarcoma but contains distinctive rosettelike structures. The tumors occurred principally as a painless, slowly growing, deeply situated mass of the proximal extremities in young to middle-aged adults (age range 14-65 years; mean 38). Although grossly circumscribed, the tumors had infiltrative borders microscopically and were composed of bland spindled cells situated in a hyalinized to myxoid stroma. The most characteristic feature of the tumor was scattered large rosettelike structures that often merged with serpinginous areas of dense hyalinization. The rosettes consisted of a central collagen core surrounded by a rim of rounded cells morphologically and immunophenotypically different from the cells of the spindled stroma. These cells expressed a number of antigens, including S-100 protein, neuron-specific enolase, and leu 22, in contrast to the stroma, which usually lacked these antigens. Of the 12 patients with available follow-up information, one patient treated with simple excision clinically developed local recurrence of the tumor 20 months after initial biopsy. No other recurrences were reported during the limited follow-up period, and no patient developed metastatic disease. However, the favorable prognosis of the patients in our series to date may relate to the limited follow-up period (approximately 3 years), as well as initial treatment by wide excision in nearly half of the patients. We regard the hyalinizing spindle cell tumor with giant rosettes as a distinctive type of low-grade fibroblastic tumor that with time may prove to behave similar to a low-grade fibromyxoid sarcoma and, hence, to represent an unusual variant thereof.
Article
Myxofibrosarcoma is one of the most common sarcomas in the extremities of elderly patients. We analysed the clinicopathologic features in a series of 75 patients. All patients were adults (range, 22-91 years; median, 66 years) with an approximately equal incidence in men and women. Thirty-five tumors arose in the lower and 25 in the upper extremities, nine on the trunk, two each in the retroperitoneum and the head and neck region, and one each in the pelvis and penis. Forty-eight cases (69.5%) were located in dermal or subcutaneous tissues. Distinctive histologic features included the following: a commonly nodular growth pattern; a myxoid matrix containing elongated, curvilinear capillaries; and fusiform, round or stellate tumor cells with indistinct cell margins, slightly eosinophilic cytoplasm, and hyperchromatic atypical nuclei. These lesions varied from a hypocellular, mainly myxoid, and purely spindle-cell appearance (low-grade neoplasms) to high-grade, pleomorphic (malignant fibrous histiocytoma-like) lesions with multinucleated giant cells, high mitotic activity, and areas of necrosis. Immunohistochemistry in 44 cases revealed only vimentin and occasional actin positivity. Ultrastructurally, tumor cells had a fibroblastic phenotype. DNA flow cytometry and proliferation analysis showed an association between aneuploidy and histologic grade. An average follow-up of 45 months (range, 5-300 months) in 60 cases has revealed local recurrence in 33 cases (54%). Thirteen patients developed metastases, and 13 tumor-related deaths occurred. A short interval to first local recurrence was associated with poor clinical outcome. The rate of local recurrence was independent of histologic grade, but only intermediate and high-grade neoplasms metastasized. The depth of the primary lesion did not influence the incidence of local recurrence. However, in deep-seated neoplasms, the incidence of metastases was higher and the percentage of tumor-related deaths was twice as high as in superficially located lesions, reflecting the fact that deep-seated lesions tended to be higher-grade, larger tumors. Myxofibrosarcoma tends to become progressively higher grade in recurrences, as demonstrated in five cases in our series. The poorly recognized low-grade myxofibrosarcoma is emphasized, as proper diagnosis and treatment and scrupulous follow-up are mandatory to avoid local recurrence and gradual tumor progression to a higher-grade neoplasm that may then metastasize.
Article
Intramuscular myxoma (IM) is a benign soft-tissue tumor that presents as a deeply seated mass confined to skeletal muscle. Surgical excision is virtually always curative. Recurrence, even after incomplete resection, is exceptional. Intramuscular myxoma is classically described as hypocellular and hypovascular, and is composed of cytologically bland stellate and bipolar fibroblasts separated by abundant extracellular myxoid matrix. What is underemphasized, however, is that IMs often show areas of increased cellularity and vascularity that can lead to a mistaken diagnosis of sarcoma, especially myxofibrosarcoma, low-grade fibromyxoid sarcoma, and myxoid liposarcoma. In this report, we describe the clinicopathologic features of 51 IMs with special emphasis on those that exhibit these "hypercellular regions." The patients included 35 women and 16 men who ranged in age from 27 to 89 (mean 52) years. The tumors measured from 2 to 15 (average 5.6) cm and all had a gelatinous, lobulated cut surface. Histologically, they all demonstrated classic hypocellular, hypovascular regions. Thirty-eight tumors contained areas of relative increased cellularity that occupied from 10 to 80% of the tumor. These foci had increased numbers of cells, more prominent vascularity, and often increased collagen content. The hypercellular regions were not associated with cytologic atypia of the constituent cells, mitotic activity, or necrosis. Follow-up information was available for 32 patients and ranged from 3 to 108 (average 30) months. No tumor recurred or metastasized. Areas of hypercellularity are common in IMs. Their recognition is important to avoid an erroneous diagnosis of sarcoma.
Article
We present a child with a rare and chemotherapy-resistant form of soft-tissue cancer, low-grade fibromyxoid sarcoma, first noted when he was 4 years old. He is the youngest patient reported to date. An 11-year-old white male presented to The University of Texas M. D. Anderson Cancer Center's Department of Pediatrics with a 7-year history of right thigh mass and pulmonary nodules, confirmed on examination. He had undergone extensive prior chemotherapy and surgery. He received chemotherapy with high-dose cyclophosphamide (7 g/m2) and later etoposide (150 mg/m2/day × 5), with only slight shrinkage of the thigh mass and none in the lungs. Subsequently the tumor in his proximal thigh and his lung metastases were resected, and radiation therapy was administered to the thigh. His disease remained stable for 12 months, but he then developed a pleural-based metastasis on the left side and new, bilateral lung metastases also. The tumors on the left side were removed; residual disease is stable after treatment for 6 months with subcutaneous alpha-interferon-2b. Low-grade fibromyxoid sarcoma is very uncommon in children. It grows slowly and metastasizes to distant organs, chiefly to the lungs. It is resistant to conventional chemotherapy, and thus far only surgery seems to have a life-prolonging effect. Newer chemotherapeutic and possibly biologic agents should be tried in future patients, in order to find an effective way to control the disease.
Article
BACKGROUND Although the histologic features of the recently described low grade fibromyxoid sarcoma are well established, to the authors' knowledge there are no reports in the literature describing the cytologic features of this tumor by fine-needle aspiration. Recognition of this lesion is important because of its indolent but metastasizing nature.METHODS The authors retrospectively reviewed their surgical pathology files for cases of low grade fibromyxoid sarcoma with a preoperative fine-needle aspiration biopsy (FNAB); three such cases were found. Immunohistochemical studies were performed in all three tumors, ultrastructural examination was performed in two tumors, and fresh tissue for cytogenetic analysis was obtained in one tumor.RESULTSAll FNABs showed similar features. The aspirates were relatively hypocellular with an abundant myxoid background; the neoplastic cells contained oval to spindle shaped nuclei with minimal pleomorphism. No capillaries or areas of fibrous tissue were identified. Cytogenetic study of one case revealed no chromosomal abnormalities. The histologic findings were characteristic for this lesion. By immunohistochemistry the tumor cells showed diffuse and strong reactivity for vimentin only; at the ultrastructural level the neoplastic spindle cells had characteristics of fibroblasts.CONCLUSIONS The cytologic features of low grade fibromyxoid sarcoma are not specific enough for a definitive diagnosis based on FNAB alone; however, correlating the cytologic and clinical findings can narrow the range of diagnosis. The differential diagnosis includes other myxoid lesions, in particular superficial or intramuscular myxoma and myxofibrosarcoma. In addition, the immunohistochemical and ultrastructural findings support a fibroblastic origin for this neoplasm. Cancer (Cancer Cytopathol) 1999;87:75–82. © 1999 American Cancer Society.
Article
A unique case of malignant peripheral nerve sheath tumor (MPNST) with perineurial cell differentiation occurring in a 63-year-old woman in a subcutis of the forearm is described. The tumor contained cellular and myxoid areas. The neoplastic cells were fusiform with distinct cell borders. They were arranged in storiform pattern and in wavy parallel cell cords in the cellular areas. Focally, a pleomorphism and mitotic activity (including atypical mitoses) similar to those of malignant fibrous histiocytoma were seen. The myxoid parts contained haphazardly oriented cells and scarce lipoblast-like multivacuolated cells mimicking a liposarcoma. In the differential diagnosis, myxoid liposarcoma, dermatofibrosarcoma protuberans, malignant fibrous histiocytoma and low-grade fibromyxoid sarcoma were considered. Immunohistochemically, perineurial differentiation was indicated by the diffuse expression of epithelial membrane antigen and focal reactivity for CD34. The tumor was negative with antibodies to S-100 protein, Leu-7, CD68 (KP1), vimentin and cytokeratin AE1/AE3. Ultrastructure of tumor cells revealed features of MPNST. No recurrence occurred in the patient during 2 years follow up.
Article
This article reviews the clinicopathological features of several recently described soft tissue tumours, namely ossifying fibromyxoid tumour, angiomyofibroblastoma, epithelioid angiosarcoma, retiform haemangioendothelioma, intra-abdominal desmoplastic small cell tumour, spindle cell liposarcoma and low grade fibromyxoid sarcoma. Conceptual changes are also discussed. These include the relationship between Ewing's sarcoma and peripheral primitive neuroectodermal tumour, the proposed use of the term atypical lipoma for a subset of well differentiated liposarcomas, and the occurrence at a wide variety of sites of inflammatory myofibroblastic lesions of uncertain biological potential. In addition, advances in the study of soft tissue lesions at the molecular and cytogenetic levels are outlined, with particular emphasis on the recent identification of tumour-specific karyotypic abnormalities in a wide variety of sarcomas.
Article
This is a case of a 46-years-old male patient with a long-standing history of lower abdominal complaints. A 6-cm measuring tumor was detected by CT and subsequently surgically removed. Classification of this tumor and prognosis was problematic in frozen section and paraffin-embedded material, including immunhistochemical studies. The immunhistochemical findings were compatible with myofibroblastic differentiation of tumor cells. The histologic pattern resembled a ”hyalinizing spindle cell tumor with giant rosettes” as recently published. Even if there were certain discrepancies in the immunohistochemical findings in our case, we also recommended treating this tumor as a low-grade sarcoma. The malignancy was also supported by marked proliferative activity demonstrated by MIB 1/ KI 67 expression in numerous tumor cells. Finally, it has not yet been determined whether the hyalinizing spindle cell tumor is a pattern associated with a certain cellular differentiation or a pattern common to several mesenchymal tumor types.
Article
Two deceptively benign-appearing, unclassifiable but very similar fibromyxoid sarcomas characterized histologically by bland, innocuous-appearing fibroblastic cells and a swirling, whorled growth pattern are presented. The tumors both occurred in women in their late twenties and were located in the soft tissues of the scapular area and the axillary-chest wall area, respectively. Lung metastases developed in both cases; one patient died 94 months after excision of the primary neoplasm, whereas the other was alive at 82 months. The designation "low-grade fibromyxoid sarcoma" is suggested for these tumors.
Article
A case is presented of low-grade fibromyxoid sarcoma involving the arm of a 52-year-old man. Low-grade fibromyxoid sarcoma is a recently described neoplasm of the deep and subcutaneous soft tissue which demonstrates a spectrum of histologic images. The current case demonstrated the typical patterns of intermixed, sweeping bands of fibrous and myxoid tissue, homogeneous foci of fibrous and myxoid tissue, focal areas of storiforming, and concentric perivascular cuffs of slender spindle cells, all lacking the nuclear anaplasia, mitotic activity, and necrosis generally associated with sarcoma. Immunohistochemical analysis performed on paraffin-embedded sections demonstrated strong labeling of the tumor cells by anti-CD34 antibody, moderate labeling for vimentin, and rare, focal positivity for muscle-specific actin. Tumor cells were negative for markers of epithelial, muscular, neural, histiocytic, melanocytic, and vascular differentiation. The constellation of histopathologic features described in this and previous reports is characteristic of low-grade fibromyxoid sarcoma. Based on this case, it appears that the immunohistochemical features of low-grade fibromyxoid sarcoma can help to exclude many cutaneous and deep soft tissue tumors from the differential diagnosis. The findings support the interpretation that the neoplasm is essentially fibroblastic in nature.
Article
Twelve cases of low-grade fibromyxoid sarcoma are presented. The patients' ages ranged from 6 to 51 years; all but three were between 26 and 46 years of age. The tumor was located in the thigh or inguinal area in four patients, in the shoulder area in three patients, and in the axilla-chest wall area, the perineum, the small bowel mesentery, the neck, and the buttock in one patient each. Tumor size (maximum dimension) varied from 3.5 to 15 cm in the nine cases in which it was known (median, 9.5 cm). Histologically, the neoplasms demonstrated contrasting fibrous and myxoid areas, a swirling, whorled growth pattern (at least in part), and bland, deceptively benign-appearing fibroblastic spindle cells; cellularity was low to moderate, mitotic figures were uncommon, and nuclear pleomorphism was usually absent or slight. Focal histologic findings in a minority of the cases included increased perivascular cellularity, moderate nuclear pleomorphism (more often in recurrent tumors), and, in myxoid areas, a rich capillary vascular network (vascularity was usually not prominent). On follow-up, nine patients experienced local recurrence (from one to numerous times); recurrence was subsequently controlled in five cases but not in the remaining four. Distant metastasis occurred in seven cases, chiefly to the lungs, but two of these patients were rendered tumor-free (to latest follow-up) by excision of metastases. At latest follow-up, four patients had died of tumor at 8, 9, 31, and 31 1/2 years, respectively, three were alive with recurrent or metastatic tumor at 6 1/2, 12 1/2, and 50 years, respectively, and five were alive and tumor-free at 5 1/2, 10 1/2, 12, 22 1/2, and 44 years, respectively. One tumor, in the patient who died at 31 years, demonstrated "dedifferentiation" at 30 years. Low-grade fibromyxoid sarcoma is a distinctive, indolent soft-tissue sarcoma.
Article
Sixty-three cases of collagenous fibroma (desmoplastic fibroblastoma) from the files of the Armed Forces Institute of Pathology were analyzed. These tumors occurred mostly in men (80%) with a median age of 50 years (range, 16 to 81 years). The lesions had a wide anatomic distribution and involved the arm (24%), shoulder girdle (19%), posterior neck or upper back (14%), feet or ankles (14%), leg (14%), hand (8%), and abdominal wall and hip (6%). The patients typically presented with a history of a painless, slowly growing mass, often of relatively long duration. The tumors ranged in size from 1 to 20 cm (median, 3.0 cm). The lesions were predominantly subcutaneous, but fascial involvement was common, and 27% of cases involved skeletal muscle. Gross examination typically showed an elongated, lobulated, or disc-shaped mass with a firm consistency and a homogeneous pearl-gray color. Histologically, the tumors often appeared well marginated on low-power examination, but most (78%) infiltrated fat or, less commonly, skeletal muscle. The lesional cells were relatively bland stellate and spindle-shaped fibroblasts separated by a collagenous or myxocollagenous matrix. Mitotic activity was absent or minimal. Some of the lesional cells had a myofibroblastic immunophenotype, as evidenced by focal reactivity for muscle-specific and alpha-smooth muscle actins. In a few cases, rare actin-positive cells were also positive for keratins. Desmin, S100 protein, and CD34 were not expressed. None of the 39 patients with follow-up (median, 11 years) developed a recurrence. Collagenous fibroma is a benign fibroblastic/myofibroblastic proliferation. The large size of some of these tumors coupled with slow growth and persistence favors a neoplastic process over a peculiar reactive proliferation. The differential diagnosis includes a variety of reactive and neoplastic fibroblastic lesions, most importantly fibromatosis and low-grade fibromyxoid sarcoma. Simple, conservative excision is the treatment of choice for collagenous fibroma.
Article
We report two cases of hyalinizing spindle cell tumors with giant rosettes arising in the pararectal space and soft tissues of the wrist in a 46-year-old man and 22-year-old-woman, respectively. Microscopically, the tumors exhibited a varied morphology, including hyalinizing hypocellular and cellular fibromatosis-like areas. The most striking morphologic feature was the formation of giant rosette like structures with collagen cores scattered throughout the tumors. Most of the tumor spindle cells were diffusely immunoreactive for lysozyme, CD-68, factor XIII and vimentin. Reactivity for smooth muscle actin, desmin and S-100 protein was not found. Ultrastructural examination of the rosettes in one case only showed normal native collagen.
Article
Low-grade fibromyxoid sarcoma is a rare, benign-appearing soft tissue neoplasm with an aggressive clinical course characterized by multiple local recurrences over several years, with ultimate spread to lung and occasionally to bone. Thus far, a total of 24 cases of low-grade fibromyxoid sarcoma have been reported in the literature. The authors present an additional case that grossly and microscopically emphasizes a pronounced lobular pattern of contrasting areas of cellularity showing high proliferative activity, as demonstrated by a proliferation marker, Ki 67 with MIB-1, and hypocellular areas with prominent myxoid component and abundant collagen fibrils. There was predominance of delicate capillary-sized stromal vessels with collagenized walls in both cellular and myxoid areas. The unusual features in this case were osseous metaplasia, prominent intranuclear pseudoinclusions, DNA tetraploidy, and membrane-bound intracytoplasmic fat vacuoles. The immunoprofile and cytologic and ultrastructural features are described. After the excision of the tumor, the patient was treated with radiotherapy without chemotherapy. The patient has been observed for 26 months and is alive without the evidence of disease. The postoperative follow-up with axial computed tomography at 24 months showed no evidence of disease, except postsurgical fibrotic changes.
Article
"Hyalinizing spindle cell tumor with giant rosettes" is a tumor recently described by Lane et al. and thought by them possibly to represent a form of low-grade fibromyxoid sarcoma. Proof of a metastatic potential was lacking. We report an example of this tumor on the arm of a 28-year-old woman. The ultrastructural study of the tumor confirmed the fibroblastic nature of the lesion, which subsequently metastasized to the lung. Histologically, the giant rosettes simulated palisaded granulomas. Our findings warrant classifying the tumor as a sarcoma, and we suggest the designation low-grade fibrosarcoma with palisaded granulomalike bodies (giant rosettes).
Article
Hyalinizing spindle cell tumor with giant rosettes (HSTGR) is a rare, recently described tumor that most commonly occurs in the peripheral deep soft tissues. A 53-year-old woman was operated on because of a mass in the broad ligament which was first noted 17 years previously. The tumor showed typical features of HSTGR. Two years after surgery, the patient is alive with no evidence of disease. To our knowledge, the present case is the first description of HSTGR occurring in the broad ligament. Despite its bland morphology, HSTGR is a low-grade sarcoma, most probably a variant of low-grade fibromyxoid sarcoma. A wide resection of the tumor and prolonged follow-up are needed because patients may develop late metastases.
Article
We examined the proliferative activity and the differentiation line of tumor cells in a case of "hyalinizing spindle cell tumor with giant rosettes" (HSCGR). A 6 cm tumor within the right deltoid muscle of a 58-year-old female was found by physical and radiographical examinations. A biopsy revealed the histological features of a spindle cell tumor with rosette-like structures. Wide excision was done under the diagnosis of HSCGR. The tumor presented as a gray-whitish, solid mass with focal pseudocystic degeneration. Immunohistochemically, the tumor cells were diffusely positive for vimentin and were also focally positive for S-100, but negative for desmin and alpha-smooth muscle actin. The cells stained positively for Ki-67 with even distribution, there being a correlation with the cellularity of the areas, with a labeling index ranging from 0.3 to 0.5%. In addition, flow cytometry revealed an almost normal diploid DNA pattern and 5.8% S-phase fraction, indicating low proliferative activity. Ultrastructurally, many tumor cells displayed discontinuous basal lamina, pinocytotic vesicles, dilated rough endoplasmic reticulum, and microfilaments with focal dense bodies. The main component of the rosette was collagenous fibrils with normal diameter and normal periodic banding. We interpreted this case of HSCGR as a low grade fibrosarcoma with remarkable differentiation of myofibroblastic lineage, and with focally accumulated, morphologically normal collagenous fibrils.
  • Weiss