Track

Case Reports

Abstract

A 40-year-old Caucasian male presented for routine skin surveillance due to his history dysplastic nevi. He had been lost to follow up for 3 years having been diagnosed with T-cell acute lymphoblastic leukemia (ALL) requiring intensive chemotherapy and ultimately an allogeneic stem cell transplant for relapsed disease. His dermatology visit marked 550 days status post-transplant, and he was notably in a complete clinical remission at that time. Incidentally, physical exam was significant for a 6 x 5 mm dome shaped yellow papule on the right mid back. Punch biopsy revealed superficial collections of foamy histiocytes as well as occasional touton giant cells. The infiltrate also consisted of lymphocytes with few scattered interstitial eosinophils. A hematolymphoid next generation sequencing assay performed on this skin tissue identified a DNMT3A p.R882C mutation, identical to the one found in the patient’s original T-cell ALL bone marrow specimen. Repeat bone marrow biopsy 60 days later failed to detect any evidence of residual leukemia or presence of the DNTM3A mutation. To our knowledge, this is one of the first cases in which mutational analysis on the skin confirmed a clonal relationship of a solitary cutaneous xanthogranuloma with a leukemic clone in the post-allo transplant setting, raising questions about the potential risk of future relapse. Moreover, it illustrates how selective use of targeted/ precision next generation sequencing assays can be used by dermatopathologists to guide oncologists in the management of patients with myeloid neoplasms.