<unk>  refers to the displacement of hemopoietic bone-marrow tissue into the peripheral blood, either by fibrosis (myelofibrosis), tumors, or granulomas.  A<unk>  blood smear is one which contains nucleated red blood cells, granulocyte precursors, and teardrop-shaped erythrocytes. This condition is also known as<unk>  anemia.<unk>  can be observed in cancers that that involve the bone marrow such as leukemia, lymphoma, and myeloma or metastatic carcinoma. The commonest cause is metastatic cancer, most often carcinomas arising in breast, lung and prostate.However any infiltrative process (e.g.,granulomatous disease) involving the marrow can produce identical findings.It should be remembered that it is also a feature of spent phase of myeloproliferative disorders.They cause marrow distortion and fibrosis which act to displace normal marrow elements and disturb mechanisms that regulate the egress of red cells and granulocytes from the marrow.
Myelophthisis
Oculo skeletal renal syndrome
Maple syrup urine disease
Diamond-Blackfan anemia
Homocystinuria
Alagille syndrome
Polycystic kidney disease 2
Myeloperoxidase deficiency