Track

Case Reports

Abstract

A 29-year-old, Fitzpatrick type II, male soldier presented to the emergency department in Germany with a six week history of unexplained lymphadenopathy, shortness of breath, fatigue, 20 pound weight loss and easy bruising. He had persistent left cervical and right occipital lymphadenopathy with skin hyperpigmentation on the right anterior thigh. A blood smear revealed numerous blast cells with flow cytometry consistent with a diagnosis of acute myeloid leukemia. Subsequent bone marrow biopsy confirmed the diagnosis, with a KMT2A gene rearrangement identified. After medical evacuation to a hospital in the United states, he noted increased, mottled dark brown to blue-tinged hyperpigmentation to his right anterior thigh, with spread to his upper and lower dorsal extremities bilaterally at areas of sun exposure. A skin punch biopsy was performed to evaluate for drug induced vs. other depositional pigmentation disorders. Hematoxylin and eosin staining shows an unaffected epidermis, with a dense periadnexal and perivascular infiltrate of large atypical blastoid cells with nuclear pleomorphism and subsets with prominent nucleoli. A myeloperoxidase stain highlights scattered immature leukocytes within the dermis, and CD4 immunohistochemical stain correlates with the immunophenotypic expression found on flow cytometry. Fontana Masson and iron special stains are negative for evidence of deposits explaining the patient’s skin hyperpigmentation, with valid controls. We report a case of leukemia cutis presenting with mottled hyperpigmentation to sun exposed skin of the extremities. We hypothesize the diffuse infiltration of leukemic cells into the dermis as causative in the apparent hyperpigmentation.