Chromosomes and causation of human cancer and leukemia. XXXIV. A case of “hypereosinophilic syndrome” with unusual cytogenetic findings in a chloroma, terminating in blastic transformation and CNS leukemia

A 47-year-old white male developed massive hepatosplenomegaly, a pleural effusion, leucocytosis, and a left parasternal mass following a relatively symptom-free persistent hypereosinophilia for about 5 years. Bone marrow aspiration and biopsy and peripheral blood differential showed eosinophilia and a shift to the left with immature cells. A high serum B12 vitamin level and low LAP activity were found. Biopsy of the soft tissue mass revealed a granulocytic sarcoma (chloroma) with a hyperdiploid karyotype (49,XY, + 10, + 15, + 19,3q-), whereas the bone marrow cells had a normal male karyotype. The patient responded temporarily to chemotherapy but eventually developed CNS leukemia and went on to terminate in a frank blastic phase. This case illustrates hypereosinophilia and a myeloproliferative syndrome characterized by a somewhat indolent chronic course evolving into "eosinophilic leukemia" and granulocytic sarcoma, CNS involvement by leukemic cells and, finally, blastic transformation. It is possible that this case represents a variant of Ph1-negative CML to which the term "chronic eosinophilic leukemia" could be justifiably applied.