metamyelocytic

Metamyelocytic refers to a developmental stage in the maturation of granulocytes, which include neutrophils, eosinophils, and basophils. This stage follows the myelocyte stage and precedes the band stage in the normal sequence of granulocyte development. Metamyelocytes are characterized by their indented or kidney-shaped nucleus, which begins to show constriction but has not yet formed the U-shaped appearance of band cells. The cytoplasm contains specific granules that determine the final granulocyte type.

In healthy individuals, metamyelocytes are typically confined to the bone marrow and are not present in peripheral blood. Their appearance in circulation, known as metamyelocytosis, serves as an important diagnostic indicator in hematology. This finding may suggest various pathological conditions such as infections, inflammatory disorders, myeloproliferative neoplasms, or bone marrow infiltration by malignant cells. The presence of metamyelocytes in blood smears is evaluated alongside other immature cells to assess the bone marrow's response to stress or disease.