nonlipid histiocytosis

n.

1. An acute, progressive, usually fatal disease occurring in infants and young children and marked by a purpuric rash, excessive tissue proliferation without lipid storage in the reticuloendothelial system, enlargement of the lymph nodes, liver, and spleen, and invasion of the spleen, liver, and bone marrow by histiocytes.Letterer-Siwe disease