Hearing Loss Revealing a Squamous Cell Carcinoma of External Auditory Canal in a Post-Irradiated Patient for Nasopharyngeal Carcinoma

Abstract

Background: Primary Carcinoma of external auditory canal (EAC) is a rare disease accounting for less than 2% of head and neck cancers and has an annual incidence of around 1 per million populations. EAC carcinoma in postirradiated nasopharyngeal carcinoma (NPC) patients occurs with an incidence of approximately 0.15%. It arises from the external ear and spreads to the temporal bone and surrounding sites. Although its rarity, it is a life threatening disease with practically a poor constant prognosis. Primary EAC carcinoma can occur with no specific symptoms. Aggressive surgery with postoperative radiation remains the usual treatment until now. We report a rare case of a squamous cell carcinoma (SCC) of EAC revealed by a progressive hearing loss as first presentation of the disease in a post-irradiated woman for NPC. Results:A 47-year-old female with a past medical history of nasopharyngeal carcinoma treated with chemo radiation therapy, presented for repeated leftsided purulent ear discharge and progressive hearing loss. Otoscopic examination revealed a tissue mass filling the left EAC. CT scan revealed a soft tissue density process filling the EAC, encroaching upon the tympanic cavity and coming into contact with the handle of the malleus neither with no acicular lyses nor EAC walls erosion. The biopsy of the mass was consistent with EAC SCC. The patient under went lateral temporal bone resection with homolateral superficial parotidectomy and selective neck dissection and completed by an adjuvant external radiation therapy [RT]. Conclusion:Post-irradiation EAC SCC has similar symptoms and invades similar regions as its primary counterpart. This entity is usually discovered in the early stage in post-irradiated EAC SCC patients comparing to the primary EAC SCC. Aggressive surgical treatment is strongly recommended, but adjuvant radiotherapy for early stage EAC SCC should be provided cautiously to prevent further radiation induced complications.