Sinus histiocytosis with massive lymphadenopathy (Rosai Dorfman Disease) - A rare case of isolated axillary lympadenopathy diagnosed on FNAC

Rosai-Dorfman disease (Sinus Histiocytosis with Massive Lymphadenopathy) is a rare disorder characterized by overproduction (proliferation) and accumulation of histiocytes in the lymph nodes of the body causing lymphadenopathy, most often involving neck. In some cases, abnormal accumulation of histiocytes may occur in other areas of the body besides the lymph nodes (extra nodal). These areas include the skin, central nervous system, kidney, and digestive tract. The case is being reported as a rare case involving isolated axillary lymph node and was diagnosed on FNAC.