Paraneoplastic Dermatomyositis as the Presenting Symptom of Tonsillar Squamous Cell Carcinoma: A Case Report.

Dermatomyositis is an autoimmune multisystem disorder affecting skin and skeletal muscle that often presents with symmetric proximal muscle weakness and cutaneous manifestations such as rash. Dermatomyositis may present as a paraneoplastic phenomenon before, concurrent with, or after the diagnosis of cancer. Several cancers, including lung, breast, stomach, ovary, and kidney carcinoma, are frequently noted as the trigger for the development of paraneoplastic dermatomyositis. Less common, nasopharyngeal carcinomas have been associated with paraneoplastic dermatomyositis. Even more rare, we present a case of a 61-year-old male found to have dermatomyositis as the presenting symptom of p16-positive squamous cell carcinoma of the oropharynx involving the left tonsil with unilateral neck involvement and solitary lung metastasis. This case highlights a rare presentation of paraneoplastic dermatomyositis and emphasizes the importance of including p16+ tonsillar carcinoma in the differential diagnosis and screening protocols following the discovery of dermatomyositis.