Bednar's tumor at right shoulder in an adult male: a case report of a rare entity.

Introduction and importance: Bednar tumor, a rare variant of dermatofibrosarcoma protuberans is a tumor with low malignant potential. Owing to limited studies, the pathogenesis and risk factor of this tumor are not clearly understood. The tumor extends from the epidermis to the dermal layers and even affects the surrounding bone. Here, the authors present a case of a 48-year-old male with a Bednar tumor, which was successfully managed by wide local excision and flap repair. Case presentation: Our patient presented to the hospital after the reappearance of mass, 6 years after the excision of the previously misdiagnosed lipoma. Vitals and systematic examination were normal. Local examination revealed an oval-shaped mass with a glistening surface on the right shoulder. The patient underwent wide excision and skin flap surgery for the treatment, and the diagnosis was confirmed through histopathological examination and immunohistochemistry for the CD34 marker. Clinical discussion: Bednar tumor is an infrequent skin tumor linked to genetic anomalies and is one of the rare variants [(<0.1%) of skin tumors]. Diagnosis can be done by histopathological examination and CD34 marker positivity via immunohistochemistry. This tumor is mistaken for lipoma, leading to recurrent growth postexcision. The tumor demands a broader resection due to the high chances of reoccurrence. Although Mohs micrographic surgery is the ideal approach, its limited availability in resource-constrained settings prompts alternative strategies. Conclusion: This case highlights the challenges of diagnosis, the rarity of the condition, and the need for vigilant follow-up due to the tumor's propensity for recurrence.