A Case of Anterior Cervical Intramuscular Schwannoma in the Strap Muscle

Abstract

Schwannoma, also known as neurilemmoma, is a benign neoplasm that originates from any nerves wrapped with a sheath made of Schwann cells. Schwannoma occurring in the head and neck region is not rare, but schwannomas of the anterior neck, especially ansa cervicalis, are extremely rare that only 7 cases have been reported to date worldwide. Although rare, it should be considered in differential diagnosis of anterior cervical mass and may be confused with other cervical and thyroid mass. We report a case of intramuscular schwannoma in the sternohyoid muscle. Preoperative diagnosis was established with an ultrasound-guided core needle biopsy. Although it was removed entirely without connection to any other nerves identified or any complication, clinically, the mass was thought to be derived from the nerve. To our knowledge, this is the first case of the intramuscular schwannoma occurring from ansa cervicalis reported in the literature.