The diagnosis from the pathological viewpoint of a blood disease.

The histopathological viewpoints of a blood diseases are namely following the cytological examinations except for the viewpoint of organ pathology and has been required only the usefulness in case with the difficulty of cytological examination. If it looks at a blood disease as hematopoietic organ disease, histopathological diagnostic study might make the new paradigm of blood diseases. In this time, I would like to present the hematological diagnosis from the pathological viewpoint by using histological bone marrow sections. *How to examine the bone marrow histology *Hematopoietic microenvironment disorder *Differential diagnosis of hypoplastic marrow lesions *Clinicopathological characteristics of Hypoplastic leukemia *Hemophagocytosis in bone marrow *How to diagnose MDS by histopathology. Bone marrow histology is the valuable diagnostic tool of many kinds of marrow disorders especial cases. By using immunohistochemistry and Giemsa staining, further information might obtain than smear film cytology. Bone marrow clot section aspirated from sternum is enough for histological examination except bone marrow biopsy. Precise cytomorphology might demonstrate by smear film than section histology. However surface phenotype would define by flow cytometric analysis, immunostaining of sections could demonstrate which cells show which markers. Structural and architectural disorder could only be represent by histology. The histological examination of bone marrow might introduce a new aspects of blood disease.