Histiocytoses in children: analysis of 120 cases and the bone marrow findings in infection-induced hemophagocytic syndrome vs malignant histiocytosis.

Retrospective analysis of childhood histiocytoses treated at the Department of Pediatrics, Ramathibodi Hospital from May 1970 till June 30, 1992 to verify the prevalence according to the recent classification, course and prognosis was conducted. Among 120 cases, 54 were Class I or Langerhan Cell Histiocytosis (LCH, previously called Histiocytosis-X). Nineteen cases were Class II: Infection-Associated Hemophagocytic Syndrome (IAHS) and Sinus Histiocytosis. Forty-seven cases were class III which included acute monocytic leukemia, juvenile CML; malignant histiocytosis, HMR, and histiocytic lymphoma. Excellent prognosis (cure) was seen in all cases of Hand-Schuller Christian Disease, eosinophilic granuloma, sinus histiocytosis with massive lymphadenopathy and many cases of Class II (except IAHS). The worse prognosis (100% mortality rate) was seen in HMR and juvenile CML. The intermediate prognosis (50%, 54%, 58.8% and 66.7% mortality rate) was seen in MH, HL, LSD and IAHS respectively. To differentiate between IAHS and MH/HMR, the prominent bone marrow findings in 12 cases of IAHS revealed that every case showed prominent hemophagocytosis by the promono-histiocytes/histiocytes, the maximal total erythroblasts (TE) were only 7.5 per cent except for 3 cases; in which one case with agranulocytosis from co-trimoxazole had 84 per cent erythroid cells, one case with prior co-trimoxazole treatment had 37 per cent TE, the last one had 40 per cent TE with massive GI bleeding while in the recovery stage of DHF. All 5 cases of HMR had prominent hemophagocytosis and increased TE (> 22%).(ABSTRACT TRUNCATED AT 250 WORDS)