Background: Adult-type rhabdomyomas (ARMs) are rare benign tumours with skeletal muscle differentiation, mainly occurring in the head and neck. Multifocal ARMs occur even less frequently, with thirty-five cases reported in the literature.
Case Report: A 60-year-old Irish male smoker presented with dysphagia and enlarging left neck swelling. Magnetic resonance imaging (MRI) of the neck showed multiple masses hyperintense to muscle on T1 and T2-imaging, including a 7.7cm left oropharyngeal mass, a 4.2cm exophytic left base of tongue mass, and multiple additional enhancing masses within the tongue, neck, and mediastinum. Panendoscopy was performed and biopsies were taken. Microscopically, the tumours comprised closely packed polygonal cells with eosinophilic cytoplasm separated by delicate fibrovascular stroma. There was no atypia or mitoses. Immunohistochemistry was positive for the myogenic marker desmin confirming the diagnosis of ARM. Elective microlaryngoscopy with laser excision of the symptomatic left base of tongue mass was performed. The patient is well post-operatively and his dysphagia has resolved.
Conclusion: ARMs are very rare tumours occurring in the head and neck. Symptoms are secondary to local compression. There have been no reported cases of malignant transformation. Although the literature base is very limited, complete surgical excision is recommended for symptomatic lesions.