A woman in her 60s with acute myeloid leukemia (AML), status post–nonallogenic bone marrow transplant and subsequent relapse, was admitted to the hospital with blast crisis (white blood cell count, 72 500/μL; 72% blasts) and tumor lysis syndrome. Flow cytometry showed myeloid blasts, most of which (≥90%) expressed CD13, CD33, CD117, and partial CD11b (≥50%). Blasts were also “highly positive” for myeloperoxidase. Stains were weak for CD4 and were negative for CD34 and HLA-DR. Cytogenetic studies revealed a normal karyotype with NPM1 and FLT3-ITD mutations. Dermatology was consulted for evaluation of 5-day history of new tender lesions on the scalp. The patient did not have a history of recent travel or trauma. Physical examination revealed several tender purpuric papules and plaques with central necrosis and hemorrhagic crusting on the scalp (Figure, A). Similar lesions were present on the right dorsal hand and left lower leg. On the right forearm, there was a tender erythematous plaque with overlying vesicles and mild hemorrhagic crusting. On the left medial thigh, there was a large indurated, tender red-brown plaque. Wound cultures and polymerase chain reaction studies from the right forearm were negative for herpes simplex virus and varicella zoster virus infections. Punch biopsy specimens from lesions on the scalp, right forearm, and left thigh were sent for histopathological and immunohistochemical assessment and tissue culture (Figure, B-D).
Saluja SS, Secrest AM, Florell SR. Acute Presentation of Tender Papules and Plaques in a Patient With Leukemia. JAMA Dermatol. 2016;152(5):571-572. doi:10.1001/jamadermatol.2015.5253