Myogenic Markers in the Evaluation of Embryonal Botryoid Rhabdomyosarcoma of the Female Genital Tract
ABSTRACT Rhabdomyosarcoma presents special diagnostic problems when it involves the uterine cervix in young children because tumor cells may lack marked atypia and may blend with the normal, immature, condensed, cellular stroma, rendering diagnosis difficult. Myogenic makers are a valuable ancillary technique for establishing a diagnosis of rhabdomyosarcoma. However, desmin positivity has been reported in cervical stromal cells, which can confound diagnosis. To determine whether immunohistochemical markers of skeletal muscle differentiation are helpful in the diagnosis of uterine botryoid rhabdomyosarcoma, we compared the immunohistochemical staining pattern of cervical rhabdomyosarcoma from 3 patients with that of normal uteri from age-matched autopsy controls by using antibodies for desmin, smooth muscle actin, muscle-specific actin, myoD1, myogenin, and WT-1. All tumors demonstrated at least focal immunopositivity for desmin, muscle-specific actin, smooth muscle actin, myoD1, and WT-1, and 1 tumor was also positive for myogenin. Autopsy controls showed only scattered subepithelial stromal immunoreactivity for desmin, muscle-specific actin, smooth muscle actin, and WT-1 and showed cytoplasmic, but not nuclear, immunopositivity for myoD1 and myogenin. Myometrium was diffusely positive for desmin and muscle-specific actin. We conclude that desmin, muscle-specific actin, smooth muscle actin, and WT1 are not specific for discriminating embryonal rhabdomyosarcoma from normal subepithelial cells in the female genital tract of children, although the number of immunopositive cells is consistently larger in rhabdomyosarcoma. Nuclear staining for myoD1 and myogenin appears not to occur in normal tissue, but it may be absent or sparse in embryonal rhabdomyosarcoma. Our findings indicate that, in this anatomic site, the diagnosis of rhabdomyosarcoma and in particular determination of tumor margins remain very reliant on histomorphology.
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ABSTRACT: The common marmoset (Callithrix jacchus) is now widely used in various research fields, including toxicology. However, information about the background pathology of this species is scarce. Here, we report a case of rhabdomyosarcoma that spontaneously occurred in a common marmoset. A 44-month-old male common marmoset was euthanized due to bilateral hind limb paralysis. At necropsy, a 2×2×5-cm intramuscular mass was observed in the lower right back. Histologically, the mass was mainly composed of interlacing bundles of spindle-shaped tumor cells. Immunohistochemically, the tumor cells were positive for myogenin, desmin, vimentin and alpha-smooth muscle actin. Ultrastructurally, the tumor cells contained bundles of myofilaments with Z-band-like structures. Thus, the tumor was diagnosed as a rhabdomyosarcoma. To our knowledge, this is the first report of spontaneous rhabdomyosarcoma that was definitely diagnosed in the common marmoset.Journal of Toxicologic Pathology 06/2013; 26(2):187-91. DOI:10.1293/tox.26.187 · 0.94 Impact Factor
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ABSTRACT: Benign and malignant soft tissue tumors and pseudotumors can rarely arise anywhere in the female genital tract. Their pathologic features as well as behavior typically overlap with those described in tumors involving typical locations. However, due to their rarity, not infrequently these tumors represent a diagnostic challenge. Their diagnosis should be based on careful gross examination, thorough sampling, and morphologic evaluation, applying a selected immunohistochemical panel and molecular studies. Accurate classification of these tumors is important because their clinical behavior, prognosis, and therapy differ markedly. This article outlines several mesenchymal lesions reported in the female genital tract, encompassing recent histologic, immunohistochemical, and molecular findings, with special emphasis on problems in the differential diagnosis.Surgical Pathology Clinics 12/2009; 2(4):755-783. DOI:10.1016/j.path.2009.08.018
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ABSTRACT: High grade uterine sarcoma and recurrent endometrial carcinoma are aggressive cancers with limited treatment options, resulting in a poor prognosis. In this research we focused in the first place on the detection of a highly immunogenic tumour-associated antigen Wilms' tumour gene 1 (WT1) in uterine tumours. We were able to reveal its overexpression in the tumour cells of high grade sarcomas and carcinosarcomas . Moreover, patients with WT1 positive tumours had a significantly worse prognosis than patients who were WT1 negative. For carcinomas, WT1 was present in only a minority of tumour cells, but in the majority of intratumoural blood vessels. Small blood vessels in the normal tissue surrounding the carcinoma were also WT1 positive, suggesting a role for WT1 in angiogenesis. WT1 was hardly expressed or absent in the non-tumour or benign tumoural uterus (myoma, polyp). The next step was to develop a targeted treatment against WT1. We opted for dendritic cell (DC) based immunotherapy. Nevertheless a basal expression of WT1 in monocytes and in vitro cultured unloaded DC was observed, the electroporation of in vitro cultured DC with WT1-mRNA resulted in a higher expression of WT1 by the DC. WT1-mRNA loaded DC were used for in vivo stimulations of T cells, resulting in the rise of WT1-specific T cells and a transient molecular response (decrease of CA125) in an end stage endometrial carcinoma patient. No toxic side effects were reported. Future in vivo research, carried out in a phase I clinical trial in our center, will reveal the ability of this new therapy to induce an immunological and possible clinical response in WT1 positive uterine cancer patients.01/2011; 3(2):89-99.