A case of pilomatrix carcinoma found in the shoulder.

To date, ~200 cases of pilomatrix carcinoma have been reported in the literature. These tumors usually present as atypical, solitary, firm nodules, most commonly in the head and neck region. Published data indicate that these tumors exhibit aggressive behavior and have a high potential for recurrence. Therefore, surgical excision with wide margins is recommended. We report a case of pilomatrix carcinoma located on the shoulder, initially presenting as a small pimple with purulent discharge in a 64-year-old man. We also review the relevant literature, with particular focus on the clinical characteristics, early identification, and treatment modalities associated with this disease.