Splenectomy in Agnogenic Myeloid Metaplasia and Postpolycythemic Myeloid Metaplasia: A Study of 34 Cases

A retrospective analysis of 34 successive splenectomies in 137 patients with myelofibrosis was carried out. Indications, complications, and response to splenectomy were compared between 22 patients with agnogenic myeloid metaplasia (AMM) and 12 patients with postpolycythemic myeloid metaplasia (PPMM). Painful splenomegaly, refractory hemolytic anemia, and refractory thrombocytopenia were the common indications for surgery. The best results were obtained for painful splenomegaly. For the other indications, half to three fourths of the patients improved with splenectomy. An increased incidence of excessive hemorrhage, infected hematoma, and early mortality was more common in the PPMM group and was found to be connected with large spleens, prolonged bleeding time, and prominent thrombocytopenia. Persistent thrombocytosis after surgery was more common in the AMM group. Leukemic transformation seemed to be related to thrombocytosis and to prior therapy with alkylating agents. Median survival following splenectomy was 43 months in the AMM group and 32 months in the PPMM group. We conclude that splenectomy has a role in improving the quality of life by ameliorating mechanical discomfort and decreasing transfusion requirement in the late phase of AMM. However, in patients with PPMM, because of the high complication rate, splenectomy should be carefully considered for specific indications on an individual basis.