Clinical spectrum of myelophthisis in cancer patients.

Myelophthisis is a form of bone marrow failure due to replacement of hematopoietic tissue by abnormal tissue, most commonly metastatic carcinomas. This results in extramedullary hematopoiesis, typically in the spleen leading to premature release of hematopoietic cells into the circulation. Peripheral blood findings may include nucleated red blood cells, tear drop forms, giant platelets, and immature leukocytes. This is called a leukoerythroblastic picture. The first case demonstrates acute myelophthisis as a presentation of pancreatic cancer. The second case is of extramedullary hematopoiesis as a manifestation of widely metastatic melanoma. The presence of a leukoerythroblastic peripheral blood picture should serve as a valuable clue about a possible underlying malignancy. This late presentation of advanced cancer may now be rarely seen because of early diagnosis and more effective therapies. Copyright 2004 Wiley-Liss, Inc.