GIANT INTRANUCLEAR GRANULES IN HUMAN MEGAKARYOCYTES - AN ULTRASTRUCTURAL-STUDY

The appearance of ''giant perichromatin granules'' to date has been co nsidered pathognomonic of nasopharyngeal angiofibroma. We present the finding of giant intranuclear granules in human megakaryocytes. The pa tient was a 34-year-old woman with a diagnosis of Sebastian platelet s yndrome. The bone marrow aspirate showed an increased number of megaka ryocytes. Ultrastructural study revealed giant perichromatin-like gran ules in the nuclei of 80% megakaryocytes. These granules were round or oval and size ranged 230 to 540 nn. Further studies are needed in our patient to determine the significance of these granules. Copyright (C ) 1998 by W.B. Saunders Company.