舌根部より発生した悪性筋上皮腫例

Abstract

A case of malignant myoepithelioma originating from the root of the tongue of a 12-year-old female is described. No symptoms except the presence of a neck mass on the left-hand side of the body were recognized. A CT scan and MRI revealed a tumor shadow localized to the root of the tongue and a solitary left cervical lymph node swelling. Biopsy specimens obtained from the left cervical lymph node were studied by light microscopy with hematoxylin and eosin staining and with immunohistochemical staining. The tumor, predominantly composed of highly anaplastic small round cells, showed positive staining with antibodies to S-100 protein, cytokeratin, vimentin and α-smooth muscle actin, on the basis of which we diagnosed malignant myoepithelioma. We performed total extirpation of the tumor, reconstruction of the tongue defect using free radial forearm flap, and left radical neck dissection. The tumor at the root of the tongue showed a histological picture which was the same as that of the cervical lymph node specimens. This tumor was determined to have originated from the minor salivary gland of the root of the tongue. Postoperatively, the tongue and left upper neck were irradiated (50 Gr). Recurrence of the tumor was observed, however, two months after surgery, in the muscular tunics of the tongue. Total extirpation of the tumor was subsequently performed, after which the clinical course has been uneventful.