A case report on a patient who presented with myelofibrosis, developed breast cancer with myeloid metaplasia, and finally showed immature NK-cell leukemia or AML without maturation with CD56 expression transformation in the pleura with extramedullary hematopoiesis: a 25-year course.

This study reports a female patient who suffered from primary myelofibrosis at 38 years of age, breast cancer with myeloid metaplasia at 49 years of age, and pleural effusion and multiple subcutaneous nodules at 62 years of age. She was finally diagnosed with immature NK-cell leukemia or AML without maturation with CD56 expression transformation of extramedullary hematopoiesis that developed in the pleura, and died 11 months later. Atypical cells in the pleural effusion had surface markers of CD13, CD33, CD34, and CD56 using a fluorescence-activated cell sorter analysis, and were positive for myeloperoxidase, CD34, CD43, and CD56 in a cell block material using an immunohistochemical method. Megakaryocytic and erythroblastic cells were also seen in the pleural effusion.