Sneaking Its Way Up: External Auditory Canal Involvement by an Otherwise Inconspicuous Nasopharyngeal Carcinoma via Spread Through the Eustachian Tube
JWY Lai, ACK Cheng, M Tong, CC Yau
Hong Kong J Radiol 2015;18:e1-6
DOI: 10.12809/hkjr1414253
External auditory canal and middle ear involvement is an uncommon initial presentation for early primary nasopharyngeal carcinoma. Previously reported cases were only associated with advanced skull base erosion or recurrence after radical treatment. We present a patient with nasopharyngeal carcinoma with a small inconspicuous primary tumour in the nasopharynx without skull base erosion, but who first presented with auditory symptoms and was found to have biopsy-proven external auditory canal involvement. Contrast-enhanced magnetic resonance imaging and 18F-fluorodeoxyglucose–positron emission tomography clearly demonstrated the route of extension via the Eustachian tube into the middle ear and mastoid air cells. This report highlights the importance of heightened vigilance for nasopharyngeal carcinoma and careful nasal endoscopic examination when encountering an undifferentiated carcinoma of the external auditory canal, especially in areas endemic for nasopharyngeal carcinoma. Similarly, otoscopic examination and modern imaging techniques such as magnetic resonance imaging or positron emission tomography are invaluable for investigating suspected nasopharyngeal carcinoma that presents as auditory symptoms.
中文摘要
不顯眼的鼻咽癌經咽鼓管進入外耳道：靜悄悄地向上游
黎詠宇、鄭志堅、唐美思、邱振中
外耳道和中耳受累是早期原發性鼻咽癌罕見的首發癥狀，過往的病例報告也僅見於廣泛顱底侵蝕或根治性放療後復發的案例。本文報告一名鼻咽癌患者最初出現聽覺功能障礙，後發現鼻咽位置有一粒不起眼的小原發腫瘤，雖無顱底侵蝕，活檢證實累及外耳道。對比增強磁共振成像（MRI）和18F-氟–正電子發射斷層掃描（PET）清楚顯示鼻咽癌擴散途徑經由咽鼓管進入中耳和乳突氣房。該病例提示當外耳道發現未分化癌時，尤其是在鼻咽癌流行的地區，應仔細進行鼻腔內鏡檢查及考慮鼻咽癌的可能性。同樣，對於有聽覺症狀並疑似鼻咽癌的病人，耳鏡檢查和現代的成像技術如MRI或PET是有效的診斷方法。