11 Rouleaux

Michelle To and Valentin Villatoro

Images of peripheral blood smears with rouleaux present. From MLS Collection, University of Alberta.

Image 1: 50x oil immersion. https://doi.org/10.7939/R3445HT5R

Image 2: 10x magnification. https://doi.org/10.7939/R3HQ3SD56

Image 3: 50x oil immersion. https://doi.org/10.7939/R3HM5313R


Cell Description:

Red blood cells are arranged into rows or linear chains, appearing on top of one another in a “coin stacking” fashion. The outlines of the the individual cells are usually seen.1,2


Cell Formation:

Can form naturally after blood is collected and allowed to sit for a long period of time.1


Similar morphology can be seen in the thick areas of a blood smear.1 Pathological rouleaux is only reported when seen in the thin areas of a peripheral blood smear where a differential would usually be performed.3


In pathological states, the increase of plasma proteins (e.g. fibrinogen, globulins) will coat the red blood cells and cause them to become “sticky” and result in rouleaux formation.1,4


Associated Disease/Clinical States:2,5

*Associated with any condition that results in the increase of plasma proteins

Acute and chronic inflammatory disorders

Plasma Cell Myeloma (Multiple Myeloma)

Polyclonal or monoclonal hyperglobulinemia


Note: Unlike with agglutination, the formation of rouleaux can be reversed with the addition of saline.2


1. Landis-Piwowar K, Landis J, Keila P. The complete blood count and peripheral blood smear evaluation. In: Clinical laboratory hematology. 3rd ed. New Jersey: Pearson; 2015. p. 154-77.

2. Rodak BF, Carr JH. Variations in shape and distribution of  erythrocytes. In: Clinical hematology atlas. 5th ed. St. Louis, Missouri: Elsevier Inc.; 2017. p. 93-106.

3. Turgeon ML. Erythrocyte morphology and inclusions.  In: Clinical hematology: theory and procedures. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1999. p. 99-111.

4. Jones KW. Evaluation of cell morphology and introduction to platelet and white blood cell morphology.  In: Clinical hematology and fundamentals of hemostasis. 5th ed. Philadelphia: F.A. Davis Company; 2009. p. 93-116.

5. Ford J. Red blood cell morphology. Int J Lab Hematol [Internet]. 2013 Mar 9 [cited 2018 Jul 12];35(3):351–7. Available from: https://doi.org/10.1111/ijlh.12082


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Rouleaux Copyright © 2019 by Michelle To and Valentin Villatoro is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

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