Dermatofibrosarcoma protuberans in childhood treated with slow Mohs micrographic surgery

Dermatofibrosarcoma protuberans (DFSP) in childhood is a rare tumor with high recurrence rates. Wide local excision can result in disfiguring mutilation, whereas Mohs micrographic surgery (MMS) reduces surgical margins. MMS in children is not performed routinely, as the required infrastructures such as a histopathology lab in close proximity to the operating room is often lacking. We retrospectively reviewed children diagnosed with DFSP treated at our hospital over 2 years. We recorded surgical treatment details, including margins, duration of inpatient stay, outcome, follow-up, and molecular genetic tumor tissue analysis. Four children with a median age of 6.8 years (range 6.0-8.8 years) were identified who had a diagnostic delay of a median of 2.5 years (range 0.5-4.0 years); all underwent complete tumor excision using the slow MMS technique using vacuum-assisted closure systems between repeated excisions and before wound closure. The median maximal safety margins were 1.5 cm (range 1.0-3.0 cm). By using vacuum-assisted closure systems, no dressing changes were needed, pain was limited, and full mobility was maintained in all children. The median total time in the hospital was 11 days (range 10-14 days). No relapses occurred during a median follow-up of 25.8 months (range 11.3-32.6 months). Collagen 1A1/platelet-derived growth factor B (COL1A1/PDGFB) translocation on chromosomes 17 and 22 was detected in all three analyzable specimens. Lesions suspected of being DFSP warrant prompt histologic evaluation; interdisciplinary management is mandatory in particular for children. Micrographic surgery allows smaller surgical margins than wide excision and should be considered as the treatment of choice in children with DFSP. The interim usage of vacuum-assisted closure systems increases patient comfort. Translocations in the COL1A1/PDGFB gene imply susceptibility to targeted treatment modalities for therapy-resistant cases.