h-caldesmon in leiomyosarcoma and tumors with smooth muscle cell-like differentiation: Its specific expression in the smooth muscle cell tumor
ABSTRACT h-Caldesmon (h-CD) is a protein combined with actin and tropomyosin that regulates cellular contraction. h-CD has been thought to be expressed exclusively in vascular and visceral smooth muscle cells (SMC). We examined h-CD expression immunohistochemically in tumors with SMC and SMC-like differentiation to clarify whether h-CD is specifically expressed in SMC tumors. The tumors examined in this study were six leiomyomas (LM), two angioleiomyomas (ALM), six leiomyosarcomas (LMS), eight rhabdomyosarcomas (RMS), eight malignant fibrous histiocytomas (MFH), four desmoids, three glomus tumors (GT), and two inflammatory myofibroblastic pseudotumors (IMP) of urinary bladder. We found that LM, ALM, LMS, and GT showed intense and extensive immunoreactivity for h-CD, whereas other tumors were completely negative for h-CD. In addition, h-CD was not present in the vascular pericytes and myofibroblasts, in contrast to actin. Although myoepithelial cells were immunopositive for h-CD, neoplastic myoepithelial cells of myoepithelial tumors and mixed tumors of the salivary gland and skin were all negative. These findings indicate that h-CD is a specific marker of both SMC and its neoplasms and that immunohistochemical detection of h-CD may facilitate the differential diagnosis between LMS and other tumors with SMC-like differentiation, including myofibroblastic tumors.
Article: Myofibrosarcoma of the Bone[Show abstract] [Hide abstract]
ABSTRACT: Myofibroblastic tumors are fairly recently established soft tissue neoplasms. Although most of them appear to be benign, myofibrosarcoma of the soft tissue, seemingly their malignant counterpart, have been reported. We describe the clinicopathologic and radiologic features of four cases of myofibrosarcoma arising from the bone. All but one of the patients were women ranging in age from 60 to 71 years. Two tumors occurred in the metaphyses of distal femurs and the others arose in the iliac bones. On radiologic examination all tumors exhibited well-demarcated lytic destructive lesions without periosteal reaction. Two tumors were localized in the bone, whereas the other two extended into surrounding soft tissues. Histologically, all tumors were composed principally of a mixture of a cell-rich fascicular area and a hypocellular fibrous area. In the former area tumor cells had rather eosinophilic spindle-shaped wavy cytoplasm and were arranged in interlacing fascicles and small storiform patterns with variable numbers of inflammatory cells. Tumors occasionally showed prominent pleomorphism, and large cells with hyperchromatic nuclei were seen. In contrast, hypocellular areas had various features, including collagenous, hyalinous scar-like and rarely keloid-like areas. Focal coagulation necroses were present in all but one tumor. Immunohistochemically, the tumors were positive for vimentin, muscle actin (HHF35), alpha-smooth muscle actin, calponin, and desmin, whereas all of them were negative for high molecular weight caldesmon. On follow-up there was one fatal case with distant metastases, whereas the clinical courses of other cases after wide resection were excellent. Myofibrosarcoma of the bone has distinctive histopathologic features, which should be distinguished from those of other bone tumors with myoid differentiation.American Journal of Surgical Pathology 01/2001; 25(12):1501-1507. DOI:10.1097/00000478-200112000-00005 · 4.59 Impact Factor
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ABSTRACT: Background Acute coronary syndrome (ACS) is mostly caused by ruptured plaques. The characteristics of rupture-prone vulnerable plaques include thin fibrous cap, large lipid core, and lower number of smooth muscle cells. Smooth muscle cells appearing in neointimal plaques are currently thought to have a uniformly synthetic phenotype, and their sub-classification has not been performed by h-caldesmon, which is supposed to be expressed in vascular smooth muscle cells that are beyond intermediately differentiated. Methods Stenotic coronary arteries were obtained from autopsy material of 51 adults. Cases were divided into 3 groups: those who died from ACS, those with a past history of ACS but died from other causes, and those without ACS history. Histological data including fibrous cap and lipid core were measured in each specimen. Immunohistochemistry for alpha-smooth muscle actin (α-SMA), h-caldesmon, and smoothelin was performed. The ratio of h-caldesmon+ cells to α-SMA+ cells was counted in the neointima. Results The positivity ratio of neointimal h-caldesmon decreased in a step-wise manner from cases without history of ACS through cases with past history of ACS to cases with ACS with statistical significance (P < 0.001). The correlation between h-caldesmon expression and progression of ACS among the different groups was more prominent than the differences in the extent of fibrous cap and lipid core. Smoothelin+ cells were rarely observed in the neointima. Conclusions Decreased positivity of h-caldesmon in neointimal smooth muscle cells is indicative of a more immature phenotype, thus may be associated with plaque vulnerability that will promote ACS.Cardiovascular Pathology 09/2014; 24(1). DOI:10.1016/j.carpath.2014.09.003 · 2.34 Impact Factor
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ABSTRACT: Background. Glomus tumors are relatively uncommon subcentimeteric benign perivascular neoplasms usually located on the fingers. With their blue-red color and common subungual location, they are commonly confused for vascular or melanocytic lesions. To date there is no comprehensive review of an institutional experience with glomus tumors. Methods. A 14-year retrospective review of all cases within University of California, Los Angeles, with either a clinical or pathological diagnosis of glomus tumor was performed. Data obtained included demographic information, tumor description, pathological diagnoses, immunohistochemical studies, radiographic and treatment information, and clinical course. Rates of concordance between clinical and pathological diagnoses and an evaluation of overlap with other entities were assessed. Results. Clinical diagnosis of glomus tumor showed concordance with a histopathological diagnosis (45.4% of cases). The most common alternate clinical diagnoses included lipoma, cyst, or angioma. A pathological diagnosis of glomus tumor was most common in the fourth to seventh decades of life. The most common presentation was a subcentimeter lesion on the digit. Deep-seated tumors had a strikingly increased risk for malignancy (33%). Radiological studies were not relied on frequently (18.2% of cases). Immunohistochemical analysis showed diffuse αSMA and MSA expression in nearly all cases (99% and 95%, respectively), with focal to diffuse CD34 immunostaining in 32% of cases. Discussion. Our study illustrates trends in the clinical versus pathologic diagnoses of glomus tumor, common competing diagnoses, a difference in demographics than is commonly reported (older age groups most commonly affected), and important differences in the use adjunctive diagnostic tools including radiology and immunohistochemistry. © The Author(s) 2015.International Journal of Surgical Pathology 01/2015; DOI:10.1177/1066896914567330 · 0.96 Impact Factor