Large Platelets

Large Platelets 

Background Information of Large Platelets

Large platelets often result to bruising and bleeding. Some of the conditions that causes abnormally large platelets are Bernard-Soulier syndrome as well as MyH9 related diseases like Epstein syndrome.

Cellular Description

They appear characteristically similar as normal platelets just larger in size. Often they can grow up to the size of a RBC.

Clinical Significance

In most laboratories, platelet counts are obtained from automated hematology analyzers. If there are numerous large platelets observed under microscope, medical technologist/scientists will invalidate the Mean Platelet Volume (MPV), as these large platelets will give an erroneous calculation. 

If the automated hematology analyzers flagged for low platelet count or abnormal platelet distribution, it is wise to look around to see if there are numerous large platelets (>2 in every 2 fields under X100 oil immersion light micrscope). This is because the automated hematology analyzers may detect large platelets as either neutrophils or lymphocytes. It is important to put a message regarding large platelets observed to highlight to the physicians' attention. 

* Mean platelet volume (MPV) is a machine-calculated measurement of the average size of platelets found in blood and is typically included in blood tests as part of the CBC. Since the average platelet size is larger when the body is producing increased numbers of platelets the MPV test results can be used to make inferences about platelet production in bone marrow or platelet destruction problems.