Monocyte, normal. Blood film. Three segmented neutrophils, two small lymphocytes. A monocyte is in the center of the field with a large, reniform nucleus and cytoplasmic color invariably distinctly different from that of neutrophils. The monocyte cytoplasm is blue-gray and the neutrophil is light tan. Note also the lighter staining, lacy nuclear appearance in the monocyte and the denser, condensed chromatin in the neutrophils.
Monocyte, normal. Blood film. A composite of four normal monocytes. (A) Folded nucleus. Modest amount of cytoplasm. (B) Folded nucleus. More ample, gray cytoplasm, cytoplasmic vacuoles (often secondary to exposure to Na2EDTA anticoagulant. (C) Reniform nucleus. Ample cytoplasm, azure granules. (D) Circular nucleus. Azure granules.
Monocyte, normal. Blood film. (A) Monocyte with horseshoe-shaped nucleus with enlarged, folded end, gray cytoplasm. (B) Band neutrophil with horseshoe-shaped nucleus and pink-orange cytoplasm. The difference in cytoplasmic coloration is an invariable distinction between monocytes and band neutrophils by light microscopy.
Monocyte, normal. Blood film. Nucleus shaped like a reversed “E”. Ample gray cytoplasm. Small lymphocyte to the right.
Monocyte, normal. Blood film. Monocyte with horseshoe-shaped nucleus. Ample, gray cytoplasm, few azure granules.
Monocyte, normal. Blood film. Monocyte with reniform nucleus. Gray ample cytoplasm. Small lymphocyte to the left and segmented neutrophil below.
Monocyte, normal. Blood film. Monocyte with horseshoe-shaped nucleus with enlarged, folded end. Ample, gray cytoplasm. Small lymphocyte to the right.
Monocytes. Blood Films. (A–E). Characteristic monocyte forms. Note normal variations in nuclear configuration. Usually, reniform.
Monocyte: transmission electron micrograph. (A) Characteristic reniform nucleus. Heterochromatin condensed along inner surface of nuclear membrane and scattered through nucleus. Cell rich in mitochondria. Cytoplasmic vacuoles are present. Occasional electron-dense primary granules. Cell periphery irregular as a result of finger-like cytoplasmic extensions. (B) Enlargement of area beneath nuclear cleft highlights mitochondria.