atypical lymphocyte


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atypical lymphocyte

An enlarged dysmorphic lymphocyte characterised by an often irregular monocyte-like nucleus that may stretch the length of the cell, with chromatin strands that parallel the length of the nucleus; nucleoli and azurophilic granules may be present. Atypical lymphocytes are seen in various non-neoplastic conditions, classically in infectious mononucleosis (<20% of circulating WBCs are atypical), toxoplasmosis, CMV infection and viral hepatitis.

ALs were formerly (and arbitrarily) grouped into three types, now of historic interest:
• Type I—Monocyoid or prolymphocytic kidney-shaped or lobulated nuclei, with densely homogeneous hypergranular chromatin, more similar to mature lymphocytes than plasma cells; cytoplasm is bubbly, eccentric and basophilic.
• Type II—Cytoplasmic radiations from the nucleus (“ballerina skirt” cells); cells have 1+ nucleoli; chromatin is less dense and cytoplasm is less foamy than type I, contains some azurophilic granules, is basophilic, and “scallops” around RBCs.
• Type III—Nuclei are coarse, span the cell’s breadth, have clumped red-to-purple chromatin with 1–4 nucleoli; the cytoplasm is abundant, basophilic, and “scallops” around adjacent RBCs. ALs have abundant cytoplasm, with basophilic condensations where they abut RBCs; mitochondria are large, numerous and scattered throughout the cytoplasm.

atypical lymphocyte

Downey cell Hematology An enlarged dysmorphic lymphocyte characterized by an often irregular monocyte-like nucleus which may stretch the length of the cell, with chromatin strands that parallel the length of the nucleus; nucleoli and azurophilic granules may be present; ALs are seen in various non-neoplastic conditions, classically in infectious mononucleosis, toxoplasmosis, CMV infection, and viral hepatitis. See Azurophilic granule.
References in periodicals archive ?
Incorporating the algorithm hypothesis that there were no EBV IgM-seropositive subjects in the heterophile-negative group without an absolute lymphocytosis or atypical lymphocyte flag, as was the case in our control group, if only this proportion of the total population were tested (492 patients) for the 3 most common viruses, there would be a savings of Can $657 595.
Atypical lymphocyte morphology, including pseudopods, split nuclei, and cytoplasmic granules, was observed in 5% of the birds.
33%) were triggered by atypical lymphocyte flags, and 9 of 12 (75%) were triggered by blast flags (abnormal lymphocytes/ lymphoblast flags).
24) A second proposed mechanism for the aggregation of IVLBCL cells to the lumina of small vessels is the aberrant expression of G protein-coupled receptor 9 (CXCR3) among atypical lymphocytes, and aberrant expression of its ligand, chemokine ligand 9 (CXCL9), by the endothelial cells of small vessels, which may mediate atypical lymphocyte migration to these areas.
The "blast" flag appeared in 33 cases but did not imply a difference in mean for atypical lymphocyte count (5.
The abnormality-specific PPV of all but the atypical lymphocyte flag was improved, whereas all overall PPVs were improved by optimization.
Proportion positive for Epstein-Barr virus, cytomegalovirus, human herpesvirus 6, Toxoplasma, and human immunodeficiency virus types 1 and 2 in heterophile-negative patients with an absolute lymphocytosis or an instrument-generated atypical lymphocyte flag.
This observation corresponds to our previous experiences with other hematology analyzers and might best be explained by the rather broad definition of an atypical lymphocyte.
Cytology disclosed atypical lymphocytes with an immunoprofile consistent with the patient's prior T-cell lymphoma (Figure 2).
4 Leukocytes, cells/[micro]L 1,800 1,300 1,600 1,600 (4,500-10,000) Neutrophils, % (50-75) 47 60 56 51 Lymphocytes, % (20-44) 36 36 39 41 Atypical lymphocytes, % (0) NA NA NA NA Platelets, /[micro]L 136,000 98,000 50,000 25,000 (130,000-400,000) AST, IU/L (0-40) 56 NA 180 383 ALT, IU/L (0-40) 32 NA 66 115 Creatine kinase, IU/L (20-270) NA NA NA 5,127 LDH, IU/L (100-225) NA NA NA NA Creatinine, mg/dL (0.
Q I would like to ask questions about atypical lymphocytes in infants and children who are less than 10 years old.

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