Necrotic ulcer: a manifestation of leukemia cutis

A 71-year-old man presented to our dermatological clinic with a 3-month history of a wound on his leg. He complained of weakness for the past few months. On his dermatological examination he had a 3x3-cm necrotic ulcer on his left tibia (Figure 1). On physical examination, there was 1 x 1-cm axillary lymphadenopathy. There was no other lymph node enlargement, hepatosplenomegaly, or gingival hypertrophy. Peripheral blood results showed 2.4x103/mm3 leukocytes (normal range 4-11 x 103/mm3) with 66% neutrophils. The hemoglobin value was 10.1 g/dL (13-18 g/dL), and the platelet count was 63x103/mm3 (150-440 x 103/mm3). No blasts were detected in a peripheral blood smear. His lactate dehydrogenase level was 567 U/L (240-480 U/L). All other results of blood chemistry were within normal limits. Punch biopsy of the skin lesion showed ulceration and dense dermal acute and chronic inflammation. There was a superficial and deep perivascular and periadnexal infiltrate of neoplastic cells composed of relatively abundant eosinophilic cytoplasm and large nuclei with blastic chromatin and occasional small nucleoli (Figure 2). Mitotic figures were prominent. Immunohistochemical stains were performed, and the neoplastic cells were CD3, CD20, CD138, and S100 protein negative. Myeloperoxidase and CD68 were positive. The histopathological findings were consistent with leukemic infiltration. Examination of bone marrow biopsy revealed that the blastic cells constituted more than 20% of the bone marrow cellularity. Cytogenetic analysis of bone marrow aspiration with fluorescence in situ hybridization was negative for inversion 16, t(8;21) and t(15;7). Histochemical stains for myeloperoxidase, sudan black, periodic acid-Schiff, and alpha naphthyl acetate were also negative. Blastic cells were DR, CD13, CD117, and CD34 positive and CD5, CD7, CD10, CD14, CD19, CD20, CD33, CD41, CD56, CD64, and CD79 negative according to flow cytometry immunophenotyping. Blastic cells were 35% in the bone marrow. Based on the findings of bone marrow examination, the patient was diagnosed as having acute myeloblastic leukeamia (AML) with minimal differentiation (subtype MO) according to French-American-British and World Health Organization classification. The examination of abdominal ultrasonography and thorocic and abominal computed tomography revealed no metastases. The patient was treated with chemotherapy that consisted of cytarabin and daunorubicin. After chemotherapy, the lesion regressed. One month after chemotherapy, the patient presented to the hospital with a complaint of fever. He was diagnosed with febrile neutropenia. He died of cardiac failure 12 months after appearance of skin infiltration.