Cutaneous Langerhans cell histiocytosis in elderly with chronic myelomonocytic leukemia.

Langerhans cell histiocytosis (LCH) is a rare histiocytic neoplasm characterized by clonal proliferation of Langerhans cells in multi-organ systems including skin, bone, pituitary gland, liver and spleen. Skin-limited involvement of LCH usually indicates an indolent clinical course; however, in rare cases, LCH is accompanied by other myeloproliferative disorders, which may determine the prognosis. An 82-year old Japanese man presented with numerous asymptomatic facial papules clinically simulating rhinophyma. Although findings of histopathology and general examination including bone marrow biopsy led to the diagnosis of cutaneous LCH, he died from chronic myelomonocytic leukemia, which emerged 10 months after the initial diagnosis of LCH. The previously reported cases of LCH concomitant with other hematological disorders are also summarized and described compared with the present case.