Haemophagocytic sinus histiocytosis with massive lymphadenopathy: early lesions, progression and involution

In a 26-year-old male suffering from haemophagocytic sinus histiocytosis with massive lymphadenopathy (SHML) five biopsies were performed during a period of 60 months. It seemed that the first change in SHML is the appearance of foamy histiocytes in the subcapsular sinuses at a time when accumulation of and haemophagocytosis by the histiocytes in the intermediary and medullary sinuses are not conspicuous. Progression of the lesions is indicated by the accumulation of haemophagocytic histiocytes in all sinuses and by the development of subcapsular xanthofibrous tissue areas, first focal, later confluent. Regression of the lymphadenomegaly may be due to gradual obliteration of the lymph node parenchyma by the subcapsular xanthofibrous tissue and by scarring. Even in the early phases of the disease the paracortical areas were underdeveloped. The immunophenotype of the foamy histiocytes populating the sinuses and the xanthofibrous areas is S-100+, Leu-M3+, VIM-13+ (CD 14), MAC 387+ N-PNA+, OKIa+, Leu-M1- (CD 15) and OKM1- (CD 11).