Giant cell tumor of the tendon sheath composed largely of epithelioid histiocytes.
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Giant cell tumor of the tendon sheath (GCTTS) is a relatively uncommon lesion. GCTTS composed largely epithelioid histiocytes are very rare. In the literature, the author could not find such cases. A 73-year-old man presented with a mass of right thumb, and resection of the mass was performed. Grossly, the mass was encapsulated and yellowish, and measured 1.5 x 2 x 2 cm. Microscopically, the mass was composed of cellular and hypocellular zones. The former was composed of spindle cells and osteoclast-like giant cells, while the latter of epithelioid clear histiocytes. The area of the former was 20%, and the latter 80%. Pigment was seen in the former elements. Mitotic figures were seen in 3/per 30 high power fields (HPFs) in the former element and 2/per 30 HPFs in the latter element. Histochemically, the pigment was hemosiderin positive with Prussian blue staining. Immunohistochemically, both the elements were negative for cytokeratin (CK) CE1/3, CK CAM5.2, CEA, HMB45, alpha-smooth muscle antigen, p53, CD10, TTF-1, and CDX2. Both the elements were positive for CD68 and Ki-67 (cellular element 30% and hypocellular element 20%). The histiocytes of the hypocellular element and osteoclast-like giant cell of the cellular element were positive for CD45. S100-protein positive Langerhans cells and CD45-positive lymphocytes were scattered. The pathological diagnosis was GCTTS. In the author's experience, GCTTS composed largely epithelioid histiocytes are very rare. In the literature, the author could not find such cases. Thus, the author reports herein this case. (+info)
Deciduoid mesothelioma: report of 21 cases with review of the literature.
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Microscopic endometrial perivascular epithelioid cell nodules: a case report with the earliest presentation of a uterine perivascular epithelioid cell tumor.
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Immunohistochemical detection of possible cellular origin of hepatic histiocytic sarcoma in mice.
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Histiocytic sarcoma (HS) spontaneously arises in the liver in mice ; however, the cellular origins of hepatic HS have not been fully clarified. In this study, we immunohistochemically analyzed 18 cases of hepatic HS from the archives of our previous experiments. In all cases, the tumor cells showed positive reactions for the macrophage-specific markers F4/80 and CD68. The cells were negative for mesenchymal cell and lymphoid cell markers, suggesting that germ cell tumor or lymphoma components do not coexist in the neoplasm. We detected scattered Ly6C(+)F4/80(-) macrophage precursors in the extramedullary hematopoietic foci and liver tissue around the HS lesions. We also showed that certain populations of HS cells express the Ly-6C antigen. These findings suggest that Ly-6C(+) macrophage progenitor cells are a possible cellular origin of murine hepatic HS. Our study identified a novel phenotype of murine HS in two of 18 cases. These cases showed the nodular accumulations of tumor cells with cohesive cytoplasm mimicking the features of epithelioid granuloma. In agreement with the expression of CD204 in epithelioid cells in granulomatous diseases, these HS cells hardly expressed CD204, although the common type HS cells were strongly positive for this antigen. These data suggest that hepatic HS may stem from Ly-6C(+) macrophage precursors. Furthermore, a subset of hepatic HS cases can possibly differentiate into epithelioid cell-like phenotypes. (+info)