P25 Two cases of multicentric dermatofibrosarcoma Protuberans (DFSP) and adenosine deaminase deficient-severe combined immunodeficiency (ADA-SCID) in a tertiary centre

Abstract

Abstract Dermatofibrosarcoma Protuberans (DFSP) are uncommon soft tissue sarcomas that are rarely metastatic though usually high-risk for local aggression and recurrence. DFSP is associated with t(17;22)(q22;q13) chromosomal translocation resulting in COL1A1-platelet-derived growth factorβ(PDGFB) fusion gene(Kesserwan et al. 2009). We present two patients referred to Dermatology at very different ages (patient A 12 years; patient B 6 months) with atrophic plaques and atypical nodules respectively, later demonstrated to be rare cases of multicentric DFSPs. Both were known adenosine deaminase deficient-severe combined immunodeficiency patients (ADA-SCID), associated with multiple additional pathologies(Ochs et al. 2007). Patient A had been treated aged 6 months by undergoing bone marrow transplant (BMT) from an unrelated donor, but did not present with skin lesions until ∼11 years later, whereas Patient B was referred to our centre from another country for BMT and had lesions incidentally detected whilst temporarily in the UK. Histology for both patients demonstrated a paucicellular highly infiltrative spindle cell proliferation in the deep dermis and subcutis and CD34 positivity, consistent with DFSP. Patient A’s tissue was sent to the Northern Genetics Service and the COL1A1-PDGFB fusion gene was detected. Both patients were referred to plastic surgery for multiple excisions (A-3; B-10 lesions). Patient A has since had two further plastic surgery procedures for further or wider excisions. An association between DFSP and ADA-SCID has become more widely reported, though as is highlighted by our two very different cases little is known about timing of presentations, optimal treatment and prognosis.