A man in his 40s with newly diagnosed acute myelogenous leukemia (AML) arising from myelodysplasia presented with fever, cough, abdominal pain, difficulty swallowing, and 1 month of neutropenia. He had abruptly developed a painful eruption on his scalp, face, and left leg 24 hours prior to presentation after being scratched in these areas by his pet cat. The patient had not received any chemotherapy or antimicrobial prophylaxis. Physical examination revealed an ill-appearing, diaphoretic, thin man with multiple erythematous to violaceous, tender, edematous, targetoid nodules and plaques with central dusky appearance on the left forearm and right upper thigh (Figure, A). Vital signs included temperature of 39.7° C, blood pressure of 141/69 mm Hg, and pulse of 122 bpm. His white blood cell count was 1.8 × 103/µL (reference range, 4.5-11 × 103/µL; to convert to ×109/L, multiply by .001), and absolute neutrophil count was 246 cells/µL (reference range, 1520-6370 cells/µL). Other laboratory values were remarkable for a red blood cell count of 2.13 × 106/µL (reference range, 3.9-5.5 × 106/µL; to convert to ×1012/L, multiply by 1), hemoglobin of 6.1 g/dL (reference range, 14-17.5 g/dL; to convert to g/L, multiply by 10), and platelet count of 14 × 103/µL (reference range 150-350 × 103/µL, to convert to ×109/L, multiply 1). Cellular cytogenetics of his AML were notable for a 5q deletion and p53 mutation. Punch biopsy specimens from the right arm and left thigh were performed for histopathologic evaluation and tissue culture. A brisk neutrophilic infiltrate was seen on histopathology (Figure, B).
Brown-Joel ZO, Vidal NY, Wanat KA. Expanding Purpura in a Neutropenic Patient. JAMA Oncol. Published online May 18, 2017. doi:10.1001/jamaoncol.2017.0781