Malignant gastrointestinal leiomyosarcoma and gastrointestinal stromal tumor with prominent osteoclast-like giant cells.

Abstract

c Context.—One case of leiomyosarcoma and one case of gastrointestinal stromal tumor with prominent osteoclastlike giant cells have so far been reported in the digestive tract. Objective.—To ascertain the clinicopathologic features and biologic behavior of these tumors, we report 3 additional cases of leiomyosarcoma of the gastrointestinal tract and one malignant gastrointestinal stromal tumor. Design.—Histologic and immunohistochemical examinations were performed. Clinical and follow-up data were recorded, and the literature was reviewed. Results.—The age of the patients ranged from 50 to 68 years (mean, 62 years). One of the lesions arose in the stomach, one in the ileum, and 2 in the colon. Three tumors showed a strong positivity for muscle actin and desmin and were diagnosed as leiomyosarcomas, 2 of them showing spindle cells and 1 of them showing epithelioid cells. The fourth tumor reacted strongly positive for c-Kit (CD117) and vimentin, and it was diagnosed as an epithelioid malignant gastrointestinal stromal tumor. All tumors were characterized by numerous osteoclast-like giant cells that were unevenly distributed and that, using immunohistochemistry, reacted strongly with CD68. Conclusions.—Malignant stromal tumors with osteoclast-like giant cells of the gastrointestinal tract are rare entities, are more commonly of a myogenic origin such as leiomyosarcoma, and seem to have an aggressive behavior. (Arch Pathol Lab Med. 2004;128:440‐443)