Adult-Type Rhabdomyoma of the Omohyoid Muscle

Abstract EN

Rhabdomyomas are benign tumors composed of mesenchymal tissue and having a histologic appearance similar to skeletal muscle.

Extracardiac rhabdomyomas are rare, and the majority of the adult subtype occur in the head and neck (H&N) region.

Diagnosis can be challenging due to fine-needle aspiration (FNA) and core needle biopsy being suspicious for sampling error from surrounding muscle or concerning for rhabdomyosarcoma.

We present a case of a slowly enlarging left neck mass in the strap musculature of a 45-year-old Hispanic male.

Multiple FNA and core biopsies failed to establish a diagnosis, and excisional biopsy was pursued revealing a hypertrophied left inferior belly of the omohyoid muscle.

Histological analysis was diagnostic of an adult-type extracardiac rhabdomyoma, with complete surgical excision being the gold standard treatment for these tumors.

The patient had an uneventful recovery.

Skeletal muscle tumors of the H&N are uncommon, and benign extracardiac rhabdomyoma must be considered in the differential diagnosis to prevent unnecessarily aggressive intervention and appropriate patient counseling before and after surgery.