1/2. Acute basophilic leukemia lacking basophil-specific antigens: the importance of cytokine receptor expression in differential diagnosis.De novo acute basophilic leukemia (ABL) is a rare form of myeloid leukemia. The low prevalence of ABL makes it difficult to define its clinical characteristics and to establish an effective therapeutic protocol. We present here a case of de novo ABL in a 64-year-old Japanese man. The diagnosis of ABL depended on the following: (1) metachromasia with toluidine blue stain, (2) intracytoplasmic theta granules identified by electron microscopy, and (3) findings obtained from extensive immunophenotypic analysis. Although blast cells lacked basophil-specific antigens such as CDw17, CD88, and FcepsilonRI, an expression profile of cytokine receptors including CD116 (GM-CSF receptor), CD117 (c-kit), and CD123 (IL-3 receptor alpha) helped to define the cellular lineage in our case. The patient achieved complete remission with intensive chemotherapy composed of idarubicin and cytosine arabinoside and was disease free during the following 30 months. We propose that immunophenotyping, especially focusing on cytokine receptors, is useful in diagnosing ABL.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/2. An unusual form of chronic myeloproliferative disorder. Aleukemic basophilic leukemia.A 52-year-old Japanese man manifested various clinical signs and symptoms such as vomiting, high fever, dyspnea, cough, sweating, palpitation, eosinophilic leukocytosis and hepatosplenomegaly. These histamine-related clinical manifestations showed a dramatic response to steroid therapy. After 10 months of hospitalization, he suddenly succumbed to candidal septicemia at the end of the third cycle of steroid therapy. autopsy revealed neoplastic proliferation of immature basophils in various internal organs without involvement of the skin. The neoplastic cells, positive immunohistochemically for leukocyte common antigen, possessed lobulated nuclei and weakly metachromatic cytoplasmic granules, predominantly of the basophil type, which exhibited weak naphthol ASD-chloroacetate esterase activity. Mast cell-type granules were also observed ultrastructurally. The neoplastic infiltration was associated with fibrosis in the liver, spleen and bone marrow and with extramedullary hematopoiesis in the liver, spleen, lymph nodes and perihypophyseal tissue. The bone marrow showed uneven and multifocal involvement. Despite the lack of leukemic manifestations and the results of chromosomal analysis, the most suitable diagnosis was aleukemic basophilic leukemia within the category of chronic myeloproliferative disorder. Kinship of this neoplasia to systemic mastocytosis is discussed.- - - - - - - - - - ranking = 0.2keywords = antigen (Clic here for more details about this article) |