Distant muscular (gluteus maximus muscle) metastasis from laryngeal squamous cell carcinoma

Clinical evidence of non-lymphatic distant metastasis has been reported in approximately 10% of cases of head and neck squamous cell carcinoma (HNSCC). The lungs are the commonest site of distant metastasis of HNSCC, followed by the bones, liver and skin. A 65-year-old male underwent supraglottic laryngectomy and left modified neck dissection for a carcinoma of the laryngeal surface of the epiglottis extending to both false cords. Eight months later the patient underwent right radical modified neck dissection for hypodermal metastatic disease involving the underlying (sternocleidomastoid) muscle. Thirty-two months later, surgical excision of a lesion in the right gluteus maximus muscle was performed. Histological study diagnosed a muscular metastasis with the same morphological aspect as the laryngeal carcinoma. The patient showed no evidence of cervical or distant recurrence at follow-up after 13 months. Although skeletal muscles represent approximately 50% of total body mass and receive a large proportion of total cardiac output, haematogenous metastases to skeletal muscle are extremely uncommon. Most skeletal muscle metastases are of pulmonary origin. Distant skeletal muscle metastasis from HNSCC is an extremely rare occurrence. Treatment options, depending upon the clinical setting, include observation, radiotherapy, chemotherapy and excision; these approaches rarely alter the patient outcome. The prognosis associated with skeletal muscle metastasis is thought to be poor, consistent with the fact that it generally occurs as a feature of systemic spread.