Sinus histiocytosis with massive lymphadenopathy (Destombes-Rosai-Dorfman syndrome) occurring as a single enlarged submandibular lymph node: a light and immunohistochemical study with review of the literature.

Sinus histiocytosis with massive lymphadenopathy (SHML) is primarily a disease of children and young adults in which there is a pronounced and persistent cervical lymph node enlargement that usually is bilateral and is accompanied by fever. The histology, which varies according to the stage of the disease, is characterized by an exuberant intrasinusoidal histiocytic proliferation. The present case involves a 4-year-old girl who had several episodes of upper respiratory infection and otitis media; subsequently, a walnut-sized enlargement developed in the left anterior portion of the neck. Results of a physical examination were essentially normal. A laboratory work-up was noncontributory. Serologic tests for toxoplasmosis, infectious mononucleosis, and cat-scratch disease were negative. Immunoelectrophoresis disclosed normal values for IgG, IgM, IgA, and IgE. The histopathology was characteristic of SHML. The lymph node demonstrated pericapsular and capsular fibrosis and widely dilated subcapsular, trabecular, and medullary sinuses packed with histiocytes and plasma cells. "Lymphophagocytosis" and large atypical histiocytes resembling Reed-Sternberg cells were noted. Immunohistochemistry demonstrated a polyclonal population of plasma cells mostly stained with rabbit anti-human igG. The cytoplasm of the histiocytes, having ingested lymphocytes, was positively stained for IgG. Other groups of lymph nodes were affected during the next several months. The patient's condition has now been followed for 2 years, and the lymphadenopathy has almost completely regressed. The site distribution of the head and neck extranodal manifestations of SHML was analyzed in 54 cases.