[Smoldering leukemia with pyoderma gangrenosum].

A 76-year-old male admitted to Surugadai Nihon University hospital complaining of general fatigue, slight fever and anorexia. The laboratory examination revealed anemia and an appearance of a few myeloblasts and 7% of monocytes in the peripheral blood. The nucleated cell count was 2 x 10(4)/microliters with 43% myeloblasts in the bone marrow aspirate. He was diagnosed as acute myelomonocytic leukemia. He did not receive any chemotherapy for leukemia because of his old age and smoldering disease. Pyoderma gangrenosum developed in the left submandibular and axillary regions about 6 months later. Three more month later, significant increase of myeloblast was recognized in the peripheral blood and the bone marrow. It has been reported that pyoderma gangrenosum precedes a remarkable increase of leukemic cells in the patients with acute leukemia in complete remission and with myelodysplastic syndrome. In our case, to, the same process was strongly suggested.