Clear Cell Sarcoma-like Tumor of GI Tract
Clear cell sarcoma-like tumor of gastrointestinal tract is composed of uniform polygonal or rounded cells arranged in sheets with focal pseudopapillary or pseudoalveolar architecture. The well-defined nests of the clear cell sarcoma of soft tissue are not seen. The cells have moderate amount of clear or lightly eosinophilic cytoplasm, centrally located round nuclei, and punctate or inconspicuous nucleoli. Basophilic macronucleoli of clear cell sarcoma of soft tissue are not seen. Mitotic activity is increased and necrosis is often present. Most cases show osteoclast-type giant cells. The distribution of these giant cells is uneven and sometimes they are absent altogether. Touton type giant cells with peripherally located nuclei of clear cell sarcoma are not seen. The image shows a tumor invading the muscularis of the small bowel wall.