Sinus Histiocytosis with Massive Lymphadenopathy (Rosai Dorfman Disease) and Anaplastic Large Cell Lymphoma

Sinus histiocytosis with massive lymphadenopathy (SHML) is a rare and benign source of lymphadenopathy first described in 1969. This disease commonly presents in children and young adults with supra-diaphragmatic lymphadenopathy mainly at cervical nodal sites, composed of a polyclonal population of histiocytes. Since its description greater than 400 cases have been described, however the literature is quiet scanty when it comes to its association with lymphomas. This case report describes a case with co-existing SHML and anaplastic large cell lymphoma (ALCL). The diagnosis of SHML in our patient did not alter the clinical outcome and patient responded well to treatment of ALCL. Clinicians should maintain a high index of suspicion in cases of infra-diaphragmatic SHML for the presence of occult lymphoma.