Splenectomy in myelofibrosis with myeloid metaplasia: a single-institutionexperience with 223 patients

In a 20-year period, 223 patients (median age, 64.8 years) with myelofibros is with myeloid metaplasia (MMM) had therapeutic splenectomy at our institu tion. Primary indications for surgery were transfusion-dependent anemia (45 .3%), symptomatic splenomegaly (39.0%), portal hypertension (10.8%), and se vere thrombocytopenia (4.9%). Operative mortality and morbidity rates were 9% and 31%, respectively The 203 survivors of surgery had a median postsple nectomy survival time (PSS) of 27 months (range, 0-155). Among preoperative variables, thrombocytopenia (platelet count less than 100 x 10(9)/L) and n onhypercellular bone marrow were identified as independent risk factors for decreased PSS. Durable remissions in constitutional symptoms, transfusion- dependent anemia, portal hypertension, and severe thrombocytopenia were ach ieved in 67%, 23%, 50%, and 0% of the patients, respectively. Histologic or cytogenetic features of bone marrow obtained before splenectomy did not pr edict a response in cytopenias, After splenectomy, substantial enlargement of the liver and marked thrombocytosis occurred in 16.1% and 22.0% of the p atients, respectively. The thrombocytosis was associated with an increased risk of perioperative thrombosis and decreased PSS, The rate of blast trans formation (BT) was 16.3%, and the risk of BT was higher in the presence of increased spleen mass and preoperative thrombocytopenia. However, the PSS o f patients with BT was not significantly different from that of patients wi thout BT. We conclude that presplenectomy thrombocytopenia in MMM may be a surrogate for advanced disease and is associated with an Increased risk of BT and inferior PSS, However, the development of BT after splenectomy may n ot affect overall survival and does not undermine the palliative role of th e procedure for the other indications. (Blood, 2000;95:2226-2233) (C) 2000 by The American society of Hematology.