Dermatofibrosarcoma Protuberans in "Slow Mohs-tion": Multidisciplinary Approach of A Pediatric Dermatofibrosarcoma Protuberans of the Scalp with Slow Mohs Micrographic Surgery and A Double Rotational-Advancement Scalp Flap.

Dermatofibrosarcoma protuberans (DFSP) is an uncommon soft-tissue sarcoma with primary incidence of 4.1 per million person-years and accounts for 0.1% of all malignancies. In patients under the age of 19, DFSP comprises 6% of cases with an annual incidence of 1 in 1,000,000. It is a slow-growing malignancy with low metastatic potential. However, DFSP is notable for its high rates of local recurrence due to local invasion with its classic "finger-like" projections into normal tissue. We discuss a case of dermatofibrosarcoma protuberans on the scalp of a 14-year-old male with delayed diagnosis, which required extensive resection through slow Mohs Micrographic Surgery (sMMS). This resection created a sizeable scalp defect of nearly 100 cm 2 , which mandated creative reconstruction using a novel double rotational-advancement scalp flap to close the defect while maintaining the patient's hairline for optimal cosmesis.