Which of the following can cause a falsely decreased platelet count?

The correct choice to identify a cause of falsely decreased platelet count is platelet clumps. In automated hematology analyzers, platelet clumping can lead to an underestimation of the platelet count. When platelets aggregate, they may be counted as a single unit rather than individually, thus resulting in a lower reported platelet count.

In contrast, schistocytes (fragmented red blood cells) and giant platelets typically do not cause a decrease in the platelet count. Schistocytes could contribute to complications in interpreting results, but they don't directly lead to a falsely decreased count. Normal platelet morphology implies that the platelets are functioning properly, and thus, should give an accurate count. Giant platelets might be large but still contribute to a higher count.

Hence, the presence of platelet clumps is significant in hematology as it directly affects how platelets are counted in lab tests, making it crucial for technologists to recognize this when analyzing results.