Eccrine Poroma: Very rare External auditory canal tumor and literature review

Abstract

Eccrine poroma is a rare benign tumor of the sweat glands, first described in 1956, that originates in the skin of the palms and soles, although it can also appear in other areas with hair, such as the head and neck. Up to 18% of these tumors can become malignant, trans­forming into highly aggressive porocarcinomas with a risk of metastasis, which justifies early resection and long-term follow-up. While these tumors are usually found on the extremities, they are very uncommon in the auricular region and the external auditory canal (EAC), where apocrine glands predominate. A clinical case describes a 48-year-old man with an eccrine poroma in the EAC, who presented symptoms such as otalgia, otorrhagia, and pro­gressive hearing loss. Tomography studies showed the auditory canal blocked by a mass, and a biopsy confirmed the diagnosis of eccrine poroma. Surgical resection was successfully performed, and after the operation, the patient showed recovery with no recurrence of the tumor. In conclusion, eccrine poroma is extremely rare in the EAC and requires histological diagnosis and complete surgical treatment, given the potential for malignancy. Adequate differential diagnosis for tumors in this area is essential due to their potential risk of malig­nant transformation.