HISTOLOGIC SPECTRUM OF CUTANEOUS INVOLVEMENT IN PATIENTS WITH MYELOGENOUS LEUKEMIA INCLUDING THE NEUTROPHILIC DERMATOSES

Background. Cutaneous manifestations of myeloid leukemia can be specific or nonspecific. The study was designed to determine the prevalence and histologic appearance of cutaneous lesions in patients with myeloid leukemia and various myeloproliferative disorders. Methods. The histologic changes of cutaneous lesions in 52 patients with myelodysplastic syndrome, polycythemia vera, and myeloid, myelomonocytic, or monocytic leukemia are presented in this study. Results. Two types of cellular infiltrates were identified. In the first group, the most common pattern was a diffuse involvement by the leukemic cells through the entire dermis with preservation of a “grenz zone” in the superficial dermis. Two cases exhibited a Kaposi's sarcoma‐like pattern, with prominent slit‐like blood‐filled spaces lined by myeloblasts against a fibrocellular stroma. The second group of lesions was characterized by dense, neutrophilic dermal infiltrates resembling acute neutrophilic dermatosis (Sweet's syndrome) or pyoderma gangrenosum. In two of these cases, scattered immature blast cells admixed with the mature neutrophilic elements were identified. Conclusions. Awareness of these different morphologic features and application of special stains are of value in the evaluation of suspicious cutaneous infiltrates in patients with myeloid leukemia and various myeloproliferative disorders.