An unusual presentation of a digital schwannoma: case report.

Abstract

Schwannomas are primary benign peripheral nerve sheath tumors. They are also known as neurilemmomas and represent less than 5 % of all upper extremity tumors [1] and 2.8 % of biopsied benign soft-tissue tumors of the hand and wrist [10]. Although most commonly found in the head and neck, schwannomas of the hand and wrist have been reported and reviewed [12]. Schwannomas of the upper extremity typically appear on the volar surface of the hand or arm. There have also been reports of unusual cases of schwannomas associated with macrodactyly [14], associated with trigger finger [16], located in the subungal region of the fingertip [8], located intraosseously [2, 11], and in the fingers of children [18, 19]. A search of the English language literature failed to reveal any reports describing the atypical presentation of a schwannoma originally diagnosed as a mucous cyst or located at the dorsal aspect of the distal interphalangeal (DIP) joint. This report presents a case of a myxoid schwannoma mimicking the clinical findings of a typical mucous cyst. Based on the surgical findings after excision and subsequent pathologic studies, the patient was diagnosed as having a myxoid schwannoma.