Sinus histiocytosis with massive lymphadenopathy (SHML) is a rare disorder of unknown etiology, usually associated with lymph node enlargement in various superficial or deep sites. It usually shows a prolonged clinical course with occasional exacerbation and remission phases. We describe the long-term follow-up of a case of SHML that showed typical clinical features and in which various therapeutic strategies were attempted. Chemotherapy and α-interferon (IFN) were ineffective; surgery was ultimately required with satisfactory results. From an extensive literature review we found different treatment strategies in SHML in the 80 cases published between 1969 and 2000. Spontaneous resolution of adenopathies is frequently observed: 32 out of 40 cases which did not receive chemotherapy, radiotherapy, or surgery were healthy at the time of publication. Radiotherapy alone showed conflicting results: 3 complete remissions (CR) were obtained in the 9 patients treated. Surgical debulking when required was effective—8/9 CR—while chemotherapy showed generally negative results. IFN has been previously employed in only one case. In conclusion, clinical observation without treatment is advisable when possible. In the presence of vital organ compression and/or extranodal localization with important clinical signs, surgical debulking may be necessary. Radiotherapy has shown limited efficacy, while chemotherapy is in general ineffective. More experience is needed to evaluate the role of IFN. Am. J. Hematol. 69:67-71, 2002. © 2002 Wiley-Liss, Inc.