Hemmi A, Hiraoka H, Mori Y, Wataya T, Sato H, Jinnai M, Yamaguchi H, Arai Y
Department of Pathology, Dokkyo University Koshigaya Hospital, Saitama, Japan.
Acta Pathol Jpn. 1988 Sep;38(9):1215-26. doi: 10.1111/j.1440-1827.1988.tb02393.x.
Malignant pleomorphic adenoma arising in the trachea has not been reported in the literature. We report here a case of malignant pleomorphic adenoma (malignant mixed tumor) occurring in the trachea of a 65-year-old woman. The tumor metastasized to the lung and the chest wall 11 years after complete resection of the primary tumor, which was a polypoid submucosal tumor, 1.3 cm in diameter. Light microscopic examination of the primary and metastatic tumors showed the presence of epithelial and stromal elements, consisting of grandular structures, foci of squamous metaplasia and a myxochondroid stroma. Many tumor cells showed myoepithelial cell features by electron microscopy, and immunoreactivity for S-100 protein and GFAP was also seen in many of them. These findings were consistent with those of pleomorphic adenoma. However, the epithelial elements were cytologically atypical with prominent mitotic figures. Infiltration of the tumor cells into the surrounding soft tissue was also seen. No foci of benign pleomorphic adenoma were found in the primary tumor. These findings indicate that this tumor was not a carcinoma ex pleomorphic adenoma, but a true malignant pleomorphic adenoma (true malignant mixed tumor) of the trachea.
气管发生的恶性多形性腺瘤在文献中尚未见报道。我们在此报告一例发生于一名65岁女性气管的恶性多形性腺瘤（恶性混合瘤）。该肿瘤在原发肿瘤（为直径1.3 cm的息肉样黏膜下肿瘤）完全切除11年后转移至肺和胸壁。对原发肿瘤和转移瘤的光镜检查显示存在上皮和间质成分，包括腺管结构、鳞状化生灶和黏液软骨样间质。电镜检查显示许多肿瘤细胞具有肌上皮细胞特征，且其中许多细胞对S-100蛋白和胶质纤维酸性蛋白也呈免疫反应性。这些发现与多形性腺瘤一致。然而，上皮成分在细胞学上具有非典型性，有明显的核分裂象。还可见肿瘤细胞浸润周围软组织。在原发肿瘤中未发现良性多形性腺瘤灶。这些发现表明该肿瘤并非多形性腺瘤恶变，而是气管真正的恶性多形性腺瘤（真正的恶性混合瘤）。
