Sinus histiocytosis with massive lymphadenopathy localized to the sella.

Sinus histiocytosis with massive lymphadenopathy (SHML) is a condition of unknown aetiology characterized by proliferation of histiocytes and lymphocytes, with the former phagocytosing the latter producing a typical histological appearance. Although first described in lymph nodes, cases have been reported in many extranodal sites, including the central nervous system. We report a case of SHML involving the sella turcica producing diabetes inspidus and pituitary dysfunction.