Congenital Rosai-Dorfman disease without lymphadenopathy.

Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disorder with massive lymphadenopathy. We here describe RDD of a neonate who presented with paleness and hepatosplenomegaly but not lymph-node swelling. Routine laboratory studies showed anemia, thrombocytopenia, and an elevated value of gamma-glutamyl transpeptidase. Histological examination of the liver revealed a proliferation of histiocytes with abundant eosinophilic cytoplasm, which were positive for S-100 protein and CD68 but not CD1a and did not reveal Birbeck granules. Radiological studies showed hepatosplenomegaly and a narrowing of the hepatic vein, which might have contributed to hypersplenism resulting in anemia and thrombocytopenia. This case is thought to be congenital RDD without lymphadenopathy.