Hypoplastic acute leukemia

Abstract

There have been few reports of acute leukemia presenting with a hypocellular bone marrow. All patients diagnosed as having acute leukemia were identified during a recent six-year interval who had blast cells plus promyelocytes of >30% and marrow cellularity of needle biopsy ≤ 50%. Of 195 patients analyzed, 15 (7.7%) fulfilled the criteria. Ten patients were men and five women; the median age was 68 years with a range of 4–82. Seven complained of fatigue of 6–12 months duration, five were seen with occult infection, and three were asymptomatic. Hepatosplenomegaly was absent in 93% and none had lymphadenopathy. Fourteen patients were pancytopenic with median leukocyte count at presentation of 1.5 × 10⁹/liter, hemoglobin of 9.0 g/dl, and platelet count of 55 × 10⁹/liter. Circulating blast cells were not observed in ten patients; in the other five they were 9/liter. The morphology of all cases appeared myeioid and Auer rods were seen in three patients; however, in one the peroxidase was negative. Classification according to FA criteria revealed ten to be M1, three to be M2, one M4, and one L2. Median survival of the entire group was seven months. Of seven patients receiving no chemotherapy, two survived longer than 1 year (14, 24.5 months), one is alive at 7+ months, and the median survival was seven months. Eight patients with life-threatening complications received various combination regimens including an anthracycline, cytosine arabinoside, 6-thioguanine, vincristine, and prednisone. Five died of treatment complications; two achieved durable complete remission and are free of disease at 17 and 27 months. It can be concluded that hypoplastic acute leukemia is a distinct nosologic entity affecting primarily older patients with myeloid leukemia. Remission induction therapy in patients who are seriously ill has a low success rate, and in some patients prolonged survival is possible with supportive care alone.