Specific but variable expression of h-caldesmon in leiomyosarcomas: an immunohistochemical reassessment of a novel myogenic marker.
ABSTRACT h-Caldesmon is considered a novel specific marker for tumors with smooth muscle differentiation. To reassess its diagnostic use, the authors evaluated the immunohistochemical expression of h-caldesmon and other myogenic markers (calponin, alpha-smooth muscle actin, HHF35, and desmin) in 30 leiomyosarcomas (external soft tissues , retroperitoneum , uterus , other sites ), 26 myofibroblastic lesions, and 26 fibrohistiocytic tumors of varying biologic potential and histology. In contrast with previous data, h-caldesmon was expressed only in 11 (36%) of the 30 leiomyosarcomas analyzed, whereas they consistently expressed actins and frequently expressed calponin (86%) and desmin (76%). Leiomyosarcomas with the expression of h-caldesmon were well or moderately differentiated and primarily confined to the retroperitoneum or uterus. All but one leiomyosarcomas in the external soft tissues examined were negative for h-caldesmon, and the h-caldesmon-negative tumors showed moderately to poorly differentiated morphology. All myofibroblastic lesions examined were negative for h-caldesmon despite their constant expressions of at least one of the other markers. h-Caldesmon was not expressed in fibrohistiocytic tumors either, although focal positivity for the other markers was seen in subsets of the tumors. Thus, h-caldesmon can be regarded as a specific myogenic marker. However, one should be aware that the expression of h-caldesmon in leiomyosarcomas can be more variable according to their locations and/or extent of smooth muscle differentiation than considered previously.
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ABSTRACT: To obtain further information regarding the frequency and degree of positivity for smooth muscle markers in a large number of malignant fibrous histiocytomas (MFHs), as an aid to accurate diagnosis. The immunohistochemical features of 100 MFHs were studied and the results were compared with those for 30 leiomyosarcomas. Eighteen cases of MFH with smooth muscle actin (SMA) positivity were examined ultrastructurally. Immunoreactivity for smooth muscle markers, such as desmin, SMA, muscle specific actin (MSA) and h-caldesmon (HCD), which is a specific marker for smooth muscle cells and their tumours, was found in 28, 30, 29, and 29 of 30 leiomyosarcomas. Immunoreactivity for desmin, SMA, MSA, and HCD was found in 17, 30, 14, and two of the MFHs. On electron microscopic examination, approximately half of the cases contained a varying proportion of myofibroblastic cells. The others had only fibroblastic or undifferentiated tumour cells. At least 30% of the cases were found to display features consistent with limited smooth muscle or myofibroblastic differentiation. A large subset of so called MFH in fact shows poorly differentiated smooth muscle or myofibroblastic features, and perhaps such tumours should be regarded as pleomorphic leiomyosarcomas and/or pleomorphic myofibroblastic sarcomas.Journal of Clinical Pathology 10/2003; 56(9):666-71. · 2.55 Impact Factor
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ABSTRACT: Immunohistochemistry is particularly important in the field of soft tissue tumours because of their variety and the frequent difficulty of diagnosis. The first part of this paper discusses useful or new antibodies, together with others that are no longer of use. The second part is devoted to the role of immunohistochemistry in the diagnosis of soft tissue tumours: identification of some rare or atypical benign lesions, identification of non-mesenchymal malignant tumours, and classification of sarcomas. The respective roles of immunohistochemistry and molecular biology are underlined.Histopathology 08/2003; 43(1):1-16. · 3.30 Impact Factor
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ABSTRACT: Leiomyosarcoma (LMS) can be categorized into uterine, retroperitoneal, nonretroperitoneal soft tissue, cutaneous, visceral, and osseous anatomic subtypes. The differential expression of smooth muscle markers, estrogen receptor (ER), progesterone receptor (PR), and Wilms tumor-1 protein (WT1) by anatomic subtype and gender was explored. A total of 78 LMS comprised of 30 uterine and 48 nonuterine tumors were studied. Nonuterine tumors were comprised of 17 soft tissue, 16 retroperitoneal, 7 cutaneous, 5 visceral, and 3 osseous subtypes. Immunohistochemical staining intensity on tissue microarray slides was scored as 0, 1+, or 2+, and cluster analysis was performed on the data. Smooth muscle actin was the most sensitive antibody (95%), followed by muscle-specific actin (91%), calponin (88%), desmin (73%), caldesmon (66%), and myosin (64%). Caldesmon and myosin were usually coexpressed, and were highest in retroperitoneal tumors (94%). There was no discernable correlation noted between histologic differentiation and smooth muscle marker expression. ER was much more common in women, with the highest frequencies noted in female retroperitoneal (86%) and uterine (63%) tumors. Nuclear WT1 was expressed in 11% of all tumors, and was limited to ER-positive uterine and female retroperitoneal tumors. Cluster analysis segregated 4 groups, most notably 1 driven by ER and PR, with the vast majority being uterine and female retroperitoneal tumors. Smooth muscle markers demonstrated variable sensitivities in LMS, with a tendency for anatomic subtypes to segregate based on expression patterns of these markers. ER defined a subgroup of uterine and female retroperitoneal tumors, and WT1 was limited to such tumors, suggesting a common line of differentiation as well as potential therapeutic targets.Cancer 08/2009; 115(18):4186-95. · 4.90 Impact Factor