惡性胸腺癌引起次發性肥厚性骨關節病變：一病例報告

Secondary Hypertrophic Osteoarthropathy Associated with Malignant Thymoma: A Case Report

肥厚性骨關節病變是一種主要表現為四肢末端骨組織與皮膚異常增生的疾病。肥厚性骨關節病變常常會次發於各種的惡性腫瘤但是卻很少發生在惡性胸腺癌的病人。本篇報告描述一位19歲的女性病人因為快速進展之杵形指、四肢遠端骨疼痛及明顯體重減少而就醫。四肢X光檢查發現兩側手指、前臂、腳趾與小腿的長骨皆出現了對稱性的骨膜增厚。在綜合併臨床症狀及放射影像表現之特點後，病人被診斷出患有肥厚性骨關節病變。因為懷疑同時患有其他會導致肥厚性骨關節病變之疾病，特別是肺部疾病，病人亦被安排接受包括血液檢查及放射影像學檢查以篩檢可能之惡性疾病。胸部X光檢查及電腦斷層顯示在前縱隔有一腫塊。在進行電腦斷層指引之穿胸切片之後，組織病理報告證實為惡性胸腺瘤。

Hypertrophic osteoarthropathy {HOA) is a syndrome characterized by abnormal proliferation of the skin and osseous tissues at the distal part of extremities. HOA has been reported to be associated with many kinds of malignant tumors but the association with malignant thymoma is rare. We report a 19-year-old female of malignant thymoma presenting initially as rapidly progressive clubbing of fingers and toes, tenderness of distal extremities and significant body weight loss. Plain radiography had demonstrated symmetrical thickening of periosteum in tubular bones of bilateral fingers, forearms, toes and lower legs. The combination of clubbing fingers and radiographic evidence of periostosis raised the diagnosis of hypertrophic osteoarthropathy. Surveys for possible underlying malignancy were undertaken. Chest radiography and computed tomography (CT) revealed an anterior mediastinal mass. The diagnosis of malignant thymoma was made by transthoracic CT guided needle biopsy.