The differential diagnosis for a neck mass in an adult can be broad. Often, we focus on the most obvious causes, including malignant or congenital causes. We present an unusual manifestation of neck swelling, specifically pyomyositis in an adult male with history of remote blunt neck trauma. Case presentation: An otherwise healthy 22-year-old African American male presented with a 3-month history of progressive left-sided neck swelling and pain refractory to antibiotics and steroids. Aside from

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... type B constitutional symptoms, he had sustained blunt trauma to the area 3 months prior. An extensive work up, including blood work, core needle biopsy, and imaging, was performed. Ultimately patient underwent an incisional biopsy, which demonstrated inflamed muscle and Staphylococcus epidermidis and Propionibacterium acnes on wound culture. Postoperatively his pain and swelling improved significantly and he has not had recurrence of symptoms. Conclusion: Pyomyositis is a bacterial infection of skeletal muscle with unclear pathogenesis but can progress to affect large muscle groups. Commonly seen in tropical countries or in immunocompromised individuals, it is a relatively rare diagnosis in temperate countries like the United States. It is not usual for initial presentation to be in the purulent stage of the infection, which can persist for several months prior to forming an abscess. This case demonstrates an atypical presentation of pyomyositis on many levels. The uncommon cervical musculature involvement, unusual bacteria cultures, competent immune system, and the involvement of prior neck trauma demonstrates the complexity in diagnosing and treating of this uncommon cause of a neck mass in an otherwise healthy adult male.