The MYH9-related disorders encompass a group of macrothrombocytopenia with or without deafness, renal failure, cataracts, and transaminitis that can present with the pathognomonic finding of Dohle-like bodies within the cytoplasm of neutrophils.
Platelet size distinguishes between inherited macrothrombocytopenias and immune thrombocytopenia.
Giant platelets observed with macrothrombocytopenia syndromes can give false low platelet counts, because the large platelets may be counted as leukocytes by automated cell counters.
In von Willebrand disease, Glanzmann thrombasthenia, and myeloproliferative disorders, the platelets have typical morphologic features, whereas giant platelets are seen in Bernard-Soulier disease and other macrothrombocytopenia syndromes.
Many patients with Bernard-Soulier disease have moderately severe thrombocytopenia with large platelets, and this disorder is included with the macrothrombocytopenia syndromes discussed herein.
In addition, [alpha]-SPD (Gray platelet syndrome) has decreased alpha granules and is usually considered a macrothrombocytopenia.
The rare macrothrombocytopenia disorders are all congenital in nature and most are inherited in an autosomal dominant fashion.
Several macrothrombocytopenia disorders are characterized by the presence of neutrophilic inclusions.