Part 2 book “Biopsy interpretation series biopsy interpretation of soft tissue tumors” has contents: Soft tissue lesions with clear or granular cells, small round cell tumors, deep vascular tumors, superficial vascular lesions and mimics, myxoid tumors of deep soft tissue, plexiform soft tissue tumors, and other contents. | 12 SOFT TISSUE LESIONS WITH CLEAR OR GRANULAR CELLS INTRODUCTION Clear cell change can be seen in some examples of myoepithelioma (Chapter 6), smooth muscle tumors (Chapter 7), atypical fibroxanthoma (Chapter 13), Ewing sarcoma (Chapter 14), rhabdomyosarcoma (Chapter 14), and gastrointestinal stromal tumor (Chapter 5). Tumors in which clear cell change can be predominant include glomus tumor (Chapter 7), alveolar soft part sarcoma, clear cell sarcoma, PEComa, and paraganglioma, as well as metastases from other organs including carcinomas. Lesions with lipoblastic and pseudolipoblastic differentiation can also enter the differential diagnosis and are discussed in Chapter 15. Granular cell or oncocytic change is seen in granular cell tumor, and in some examples of hibernoma (Chapter 15), myoepithelioma (Chapter 7), smooth muscle tumors (Chapter 6), nerve sheath tumors (Chapter 9), dermatofibroma (Chapter 4), dermatofibrosarcoma protuberans (Chapter 4), atypical fibroxanthoma (Chapter 13), and benign and malignant PEComas. Finally, reactive and neoplastic histiocytic proliferations can present in soft tissue as clear or granular cell tumors. The differential diagnoses are summarized in Tables and . CLEAR CELL SARCOMA OF SOFT TISSUE Clinical Features This is a tumor of young adults (more often in females) that arises predominantly in the extremities, especially the foot and rarely in trunk or head and neck sites as a slowly growing firm mass. The usual location is deep subcutaneous or subfascial tissue, often with involvement of tendon sheath or aponeurosis. This is an aggressive neoplasm that metastasizes to lymph node, lung and bone, with survival rates of 67%, 33%, and 10% after 5, 10, and 15 years, A genetically distinct subset of clear cell sarcoma arises in the gastrointestinal tract, where it presents with obstruction, bleeding, or mass effect. Neither subtype is related to clear cell sarcoma of kidney. 256 Epidermal hyperplasia, .
