Adult-Type Rhabdomyoma of the Omohyoid Muscle.

Area of Science:

• Oncology
• Pathology
• Surgical Oncology

Background:

• Rhabdomyomas are benign mesenchymal tumors resembling skeletal muscle.
• Extracardiac rhabdomyomas, particularly the adult subtype, predominantly occur in the head and neck region.
• Diagnosis can be difficult due to potential misinterpretation of fine-needle aspiration (FNA) and core biopsies.

Observation:

• A case of a slowly enlarging left neck mass in the strap musculature of a 45-year-old male is presented.
• Multiple FNA and core biopsies were inconclusive, initially raising suspicion for sampling error or rhabdomyosarcoma.
• Excisional biopsy revealed a hypertrophied left inferior belly of the omohyoid muscle.

Findings:

• Histological analysis confirmed the diagnosis of an adult-type extracardiac rhabdomyoma.
• Complete surgical excision is the established gold standard treatment for these benign tumors.
• The patient experienced an uncomplicated recovery following surgical intervention.

Implications:

• Benign extracardiac rhabdomyoma should be included in the differential diagnosis for head and neck skeletal muscle tumors.
• Accurate diagnosis is crucial to avoid unnecessary aggressive treatments and guide appropriate patient management.
• Consideration of this rare entity aids in effective patient counseling and surgical planning.