Platelets in primary thrombocythemia: electron microscopic study.

The ultrastructural analysis of platelets from patients with Primary Thrombocythemia (PT) showed some anomalous features. Platelets having structural modifications of their organelles were observed and a decrease in the number of dense bodies was seen. Freeze-fracture analysis of the plasma membrane of platelets from PT patients showed a significant increase in the number of intramembranous particles (IMP).