Cytodiagnosis of alveolar soft part sarcoma: Report of two cases with special emphasis on the first orbital lesion diagnosed by aspiration cytology
A 43-year-old male presented with a slowly growing mass in the right thigh for 7 years, which rapidly increased in size during the last few months. There was no history of fever or trauma. A well-defined firm, nontender swelling measuring 10 × 8 cm was appreciated, situated deep to quadriceps, with smooth surface and prominent vessels on the overlying skin. No inguinal lymph nodes were palpable. On MRI, a well-demarcated heterointense lesion was seen in the anterior compartment of the thigh with no bony involvement. Angiography showed hypervascular tumor with feeder vessels from the femoral artery. Fine-needle aspiration cytology (FNAC) from the swelling yielded hemorrhagic cellular smears displaying numerous dissociated cells, stripped naked nuclei, binucleated cells and few cohesive clusters consisting of polyhedral cells entrapped in thin fibrous septae forming small abortive alveolar clusters. These cells had abundant clear cytoplasm, central to eccentrically placed nuclei and prominent central nucleoli. A diagnosis of ASPS was considered, with differential diagnoses of metastatic renal (clear) cell carcinoma (RCC), clear cell sarcoma of tendon sheath and granular cell tumor (GCT). Wide excision and ligation of feeder vessels were carried out. On histopathology, the tumor cells were separated by fibrous tissue into well-defined nests and some of the central cells were detached to form the typical alveolar pattern of ASPS. PAS stain showed diastase-resistant intracytoplasmic needle-like structures []. The patient died of lung metastasis after 9 months of surgical excision.