Send to

Choose Destination
J Clin Pathol. 2014 Dec;67(12):1062-6. doi: 10.1136/jclinpath-2014-202545. Epub 2014 Sep 1.

Predictive significance of absolute lymphocyte count and morphology in adults with a new onset peripheral blood lymphocytosis.

Author information

Division of Hematopathology, Diagnostic Services Manitoba and University of Manitoba, Winnipeg, Manitoba, Canada.
School of Medicine, McGill University, Montreal, Quebec, Canada.
Division of Hematopathology, Department of Pathology and Laboratory Medicine, QEII Health Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada.
Department of Pathology & Laboratory Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.



Lymphocytosis is commonly encountered in the haematology laboratory. Evaluation of blood films is an important screening tool for differentiating between reactive and malignant processes. The optimal lymphocyte number to trigger morphological evaluation of the smear has not been well defined in the literature. Likewise, the significance of lymphocyte morphology has not been well studied and there are no consensus guidelines or follow-up recommendations available. We attempt to evaluate the significance of lymphocyte morphology and to define the best possible cut-off value of absolute lymphocyte count for morphology review.


71 adult patients with newly detected lymphocytosis of 5.0×10(9)/L or more were categorised to either a reactive process or a lymphoproliferative disorder. We performed statistical analysis and morphology review to compare the difference in age, gender, lymphocyte count and morphological features between the two groups. Receiver operating characteristic analysis was performed to determine an optimal lymphocyte number to trigger morphology review.


Lymphoproliferative disorders are associated with advanced age and higher lymphocyte count. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of lymphocyte morphology as a screening test were 0.9, 0.59, 0.60, 0.58 and 0.71, respectively. The optimal cut-off of lymphocyte number for morphology review was found to be close to 7×10(9)/L.


We found a moderate interobserver agreement for the morphological assessment. 'Reactive' morphology was very predictive of a reactive process, but 'malignant' morphology was a poor predictor of a lymphoproliferative disorder.


LYMPHOCYTES; MORPHOLOGY; diagnostic screening

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center