涙腺原発の粘表皮癌の1例

A case of mucoepidermoid carcinoma of the lacrimal gland

　66歳男性が3か月前からの右眼球突出と複視で受診した。11年前に脳梗塞，3年前に胃癌手術の既往があり，11年前から右眼窩内の占拠性病変が発見されている。画像診断で，右眼窩の上外側部に境界明瞭な腫瘤があった。腫瘤は眼窩の上外側壁に広く接し，骨浸潤が疑われるCT所見があり，眼球を圧迫していた。複視と眼球突出が悪化し，眼窩内容除去術を行った。組織学的には腫瘍は粘表皮癌であり，涙腺由来であると推定された。摘出した腫瘍塊の断端に腫瘍細胞があったために，化学療法と放射線照射を行い，以後6か月間，再発はない。粘表皮癌は緩徐に発育し，組織型によっては予後不良であるので，今後の長期観察が必要である。

A 66-year-old male presented with diplopia and proptosis of his right eye since 3 months before. He had a history of cerebral infarction 11 years before and surgery for gastric carcinoma 3 years before. A space-occupying lesion had been detected in the right orbit 11 years before. Diagnostic imaging showed a well-defined tumor attached extensively to the superior temporal orbital wall. Computed tomography showed suspected bone infiltration and compression to the eyeball. Orbital exenteration was performed after progression of diplopia and proptosis. Histological studies showed the tumor to be a poorly differentiated mucoepidermoid carcinoma probably originating from the lacrimal gland. Additional chemotherapy and radiation were performed because of the pres-ence of tumor cells in the margin of excised specimen.There has been no recurrence during 6 months after surgery. Mucoepidermoid carcinoma is characterized by slow progression with occasional poor prognosis when poorly differentiated, necessitating a long-term follow up.