Primary diffuse large B-cell lymphoma of the external auditory canal with extensive local extension: A case report and literature review

Introduction: Lymphoma is the second most frequent type of malignancy in the head and neck region after squamous cell carcinoma, but the external auditory canal (EAC) is an extremely rare primary site, with only ۱۳ cases reported worldwide to date. Case report: We report the case of a middle‑aged woman who presented with a four‑month history of right EAC swelling, reduced hearing and intermittent otalgia. Over the following two months, she developed right preauricular and cervical swelling. Radiological evaluation revealed an enhancing mass at the right EAC with extensive local extension. Histopathological and immunohistochemical analysis confirmed the diagnosis of lymphoma. In this case, determination of the primary site is challenging due to the extensive involvement of multiple adjacent structures. However, we believed the EAC is the most probable primary site, given that EAC swelling was the initial presenting symptom, although this cannot be established with certainty. Conclusion: The diagnosis of EAC lymphoma is challenging due to the rarity of the disease, non-specific clinical presentation, commonly misdiagnosis as a benign lesion or infection at initial presentation and difficulty in getting appropriate amounts of biopsy sample for histopathology examination and immunohistochemistry studies. In addition, extensive involvement of surrounding structures at the time of presentation may hinder accurate identification of the primary site. There is no well-established consensus on treatment guidelines, while prognosis primarily determined by the lymphoma subtype, its clinical behaviour, the presence of B symptoms, and final staging.

کلیدواژه ها:

External auditory canal ، Lymphoma ، chemotherapy