Sasaguri T, Tanimoto A, Arima N, Hamada T, Hashimoto H, Sasaguri Y
Department of Pathology and Cell Biology, School of Medicine, University of Occupational Health, Kitakyushu, Japan.
Pathol Int. 1999 Jun;49(6):571-6. doi: 10.1046/j.1440-1827.1999.00912.x.
A myoepithelioma occurred in the subcutaneous tissue of the right shoulder of a 28-year-old man. The well-demarcated nodular tumor (3. 0 x 2.8 cm) was located in the subcutaneous tissue with no adhesion to the deltoid muscle. The tumor was composed of a fascicular proliferation of spindle cells with variable amounts of stroma and showed areas of sheets of epithelioid cells. In most areas, the tumor cells had uniform nuclei, but pleomorphic epithelioid cells were focally present. Mitotic activity was three per 10 high-power fields. No ductular structure was found throughout the tumor. Immunohistochemical and ultrastructural studies confirmed the myoepithelial origin of the tumor cells. The occurrence of myoepithelioma in the subcutaneous tissue has been rarely reported. Even though the tumor showed no aggressive behavior on the 2-year follow-up, it is still too early to comment definitely on the behav- ior of myoepithelioma of the subcutaneous tissue. This case provides further information about soft tissue myoepithelioma.
一名28岁男性右肩部皮下组织发生了肌上皮瘤。边界清晰的结节状肿瘤（3.0×2.8 cm）位于皮下组织，与三角肌无粘连。肿瘤由梭形细胞束状增生构成，伴有数量不等的间质，并可见上皮样细胞片状区域。在大多数区域，肿瘤细胞具有一致的细胞核，但局灶可见多形性上皮样细胞。每10个高倍视野有3个有丝分裂象。整个肿瘤未见导管结构。免疫组化和超微结构研究证实肿瘤细胞的肌上皮起源。皮下组织发生肌上皮瘤的情况鲜有报道。尽管该肿瘤在2年随访中未表现出侵袭性行为，但对皮下组织肌上皮瘤的行为进行明确评价仍为时过早。本病例为软组织肌上皮瘤提供了更多信息。
