Hemmorhagic Cutaneous Ancient Schwannoma of The Mastoid: A Systematic Review

Abstract

Schwannomas synonymously known as neurilemmomas or neurinomas are uncommon benign neoplasms of neural sheath origin. They account for 5% of all benign soft-tissue tumors. 6%–8% of tumors occur intracranially and 25%–45% occur extracranially in the head-and-neck region, of which cutaneous schwannomas located in the dermis or subcutaneous tissue in the head and neck are an unusual entity. Of the seven subtypes described by Erlandson, ancient schwannoma is a very rare distinctive histopathological variant resulting from long-term degenerative changes and accounts for 0.8% of all soft-tissue tumors. This seminal article is a systematic review of schwannomas in the ear in its entirety from 1977 to 2023 along with a case report of a profusely bleeding cutaneous ancient schwannoma occurring in the mastoid region in a swelling of a short duration of 6 months in a 75 year old female. To the best of our knowledge, this case has two firsts to its credit. It is the first reported case of an ancient schwannoma in the mastoid region and also the first reported case presenting with bleeding from the schwannoma. Due to its rarity, ancient schwannoma must be included in the differential diagnosis for any bleeding mass in the ear to avoid an erroneous diagnosis of malignancy.