Dermatofibrosarcoma protuberans (DFSP) in six patients with ADA-SCID

10570 Background: DFSP is a rare malignant skin tumor associated with a characteristic chromosomal translocation (t(17;22)(q22;q13)), resulting in the COL1A1-PDGFB fusion gene. We originally diagnosed DFSP in two patients affected with a rare form of severe combined immunodeficiency due to adenosine deaminase deficiency (ADA-SCID). The association of these two rare conditions has been described in two other cases, which prompted us to screen for DFSP systematically in patients with ADA-SCID. Methods: Eight ADA-SCID patients were evaluated with complete dermatological exam and skin biopsy. Molecular analysis (FISH and/or RT-PCR) and karyotype were performed when possible. Results: Six patients (age 2, 2, 5, 9, 12 and 22 years) were found to have DFSP. Five patients had between 4 and 12 multicentric lesions over the trunk and extremities. One patient had a single lesion. Most lesions appeared as 2–15 mm tan atrophic plaques. Nodular lesions were present in 3 patients. All lesions showed a spindle cell proli...