Unique Case of Giant Adult Paratesticular Spindle Cell Rhabdomyosarcoma
ABSTRACT A 50-year-old unmarried rural man was referred for a giant painless scrotal lump which had developed over a period of about six years. At the admission physical examination disclosed a large swelling scrotum and palpable left supraclavicular lymph nodes. Blood counts, renal and hepatic function tests, lactate dehydrogenase, beta-HCG, and alpha-fetoprotein were normal. Computed tomographic scan of thorax and abdomen revealed supraclavicular, mediastinal, and retroperitoneal adenopathies. The patient underwent right-sided radical orchiectomy. The final pathological diagnosis was paratesticular spindle cell rhabdomyosarcoma. Unfortunately, few days after surgery, patient presented a clinical and laboratory picture of disseminated intravascular coagulation followed by exitus.
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ABSTRACT: Rhabdomyosarcoma has traditionally been subclassified into alveolar, embryonal, and pleomorphic variants. Less commonly, spindle-cell, neuroendocrine, sclerosing, and lipid-rich or clear-cell subtypes are seen. The author recently encountered a myogenic sarcoma, with all the common markers of rhabdomyosarcoma, but expressing the unusual features of alpha-smooth-muscle actin and abundant rough endoplasmic reticulum (rER). This myogenic sarcoma, therefore, exhibited four lines of differentiation, and is documented here. The patient was a 65-year-old man with an inguinal soft tissue mass. Following surgical excision, the patient was given radiotherapy and was well without disease after 6 years. The tumor was positive for vimentin, desmin, alpha-smooth-muscle actin, alpha-sarcomeric actin, myogenin, MyoD1, and CD68. Cytoplasm was dominated by abundant rER intermingled with lipid droplets and lysosomes. Cell surfaces exhibited microvillous processes and focal adhesions, but no lamina. Subplasmalemmal smooth-muscle-type myofilaments with focal densities and rare sarcomeric filaments were seen. The low level of expression of some markers was interpreted as consistent with a poorly differentiated tumor. Given the four lines of differentiation--striated muscle, smooth muscle, fibroblastic, and histiocytic--a name reflecting its phenotype would be pleomorphic rhabdomyosarcoma showing smooth-muscle and fibrohistiocytic differentiation.Ultrastructural Pathology 02/2010; 34(1):42-7. DOI:10.3109/01913120903353795 · 1.13 Impact Factor