Extrapulmonary small cell carcinoma of the external auditory canal: a case report and review of the literature.

Extrapulmonary small cell carcinoma (EPSCC) affecting the external auditory canal (EAC) is uncommon. We herein report a case involving a 56-year-old man with EPSCC of the EAC who had a 48-year history of recurrent purulent discharge in both ears and a 20-day history of right ear pain and hemorrhage followed by incomplete right eyelid closure and an askew mouth. He underwent surgical removal of middle ear granulation tissue, residual ossicles, and a right EAC mass. Postoperatively, pathomorphological examination combined with immunohistochemical staining supported a diagnosis of small cell carcinoma. Radiation therapy at a dose of 60.06 Gy in 33 daily fractions was completed 1 month after surgery, and synchronous etoposide-cisplatin regimen chemotherapy was performed for two cycles and four sequential cycles. One year postoperatively, magnetic resonance imaging showed no tumor in the ear; however, computed tomography showed multiple liver space-occupying lesions that were considered to indicate liver metastasis. Further chemotherapy was performed, but the patient died 15 months postoperatively. This case indicates that timely and accurate chemoradiotherapy is likely the most reasonable approach to EPSCC of the EAC given the aggressiveness of this tumor.