Morpheaform Dermatofibrosarcoma Protuberans Mimicking Panniculitis: A Case Report

We present the case of a 21-year-old female with a 2-year history of a slowly enlarging, asymptomatic violaceous atrophic plaque on the left lower abdomen. Ultrasonography suggested panniculitis, but persistent lesion prompted skin biopsy, which revealed storiform spindle cells with dermal sclerosis and subcutaneous honeycomb infiltration; immunohistochemistry demonstrated diffuse CD34 positivity, confirming morpheaform dermatofibrosarcoma protuberans (DFSP). This rare variant of DFSP lacks the classic protuberant nodules and is easily mistaken for benign inflammatory or fibrosing conditions. Diagnosis and management are challenging-in part due to its rarity, but largely because imaging findings are often nonspecific and may misleadingly support inflammatory disorders. Our case highlights that morpheaform DFSP can closely mimic panniculitis both clinically and on ultrasound. Here we discuss the clinical features, diagnostic pitfalls, and therapeutic approach to morpheaform DFSP, in the hope that greater awareness will lead to earlier recognition and improved outcomes.