Platelet Estimate from White Cell and Platelet Disorders: Peripheral Blood Clues to Nonneoplastic Conditions, presented by MediaLab

White Blood Cell Disorders and Platelets:: Peripheral Smear Review Introduction

Platelet Estimate

The findings in the photograph from a peripheral blood smear would elicit a report comment of "increased platelets" of some high magnitude, such as "marked" or "4+".
Estimates of platelet counts from review of a peripheral blood should be made on each smear examined. This provides a simple estimate of "high" or "low" or corroborates the value generated from an electronic cell counter.
A formula for estimating platelet counts must be established in each laboratory. Following is a guideline: 5/oil power field (OPF) = 100,000/cumm; each platelet thereafter = 10,000/cumm. Thus, if an average of 10 platelets/OPF are observed, the estimated platelet count is 150,000.cumm.
Such a counting scheme for platelets when clustered as in the photograph is probably not needed, as there are more than 100 platelets in the field. This translates into a platelet count of 1 million/cumm or more.
This peripheral smear observation, however, would serve to corroborate an electronic platelet count of 1.2 million/ cumm.

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