Sinus histiocytosis with massive lymphadenopathy: a case of simultaneous upper respiratory tract and CNS disease without lymphadenopathy.

The authors describe a 20-year-old man who initially developed an intradural mass in the upper cervical region and subsequently presented with nasal/paranasal sinus and posterior fossa masses, well demonstrated by CT and MR. Histopathology demonstrated dense fibrous tissue, aggregates of histiocytes with round to oval vesicular nuclei, and other features diagnostic of Rosai-Dorfman disease; a right nasal biopsy prior to surgery showed similar microscopic findings.