A blood film that could have averted a splenectomy
Authors: Niharendu Ghara, Sajir Mohamedbhai, Barbara J Bain
Journal: American Journal of Hematology (2014)

The patient had been generally healthy without any bleeding manifestations. His haemostasis had fortunately not been challenged. He had apparently been known to be thrombocytopenic since childhood, but had not been offered any diagnosis. His father had also been thrombocytopenic all his life and had undergone splenectomy as a child without any improvement in his platelet count. The propositus was unaware of any definitive diagnosis having been made in his father, but believed that immune thrombocytopenia was suspected. Unfortunately the patient's father had died a few years earlier of a brain tumour and hence macrothrombocytopenia could not be confirmed or excluded. We postulate that the father of the propositus suffered from the same condition as his son and had undergone an unnecessary splenectomy subjecting him, from a relatively young age, to the risks of hyposplenism without there being any benefit. A careful examination of the blood film of the father very likely would have averted the splenectomy. Patients with MYH9-related disease have not infrequently been subjected to corticosteroids, azathioprine, high dose intravenous immunoglobulin or splenectomy following misdiagnosis1. The patient had stable but persistent mild elevation of serum creatinine with structurally normal kidneys. He does not have any visual symptoms or physical evidence of cataracts or a hearing abnormality. ‘MYH9-related disease' is an umbrella term now used for a group of autosomal dominant inherited conditions resulting from mutation in MYH9, the gene that encodes non-muscle myosin heavy chain type IIA. Depending on the presence and nature of any associated abnormalities these conditions were previously described as eponymous syndromes, May−Hegglin anomaly, Epstein syndrome, Fechtner syndrome and Sebastian syndrome, with macrothrombocytopenia and sometimes various combinations of nephritis, cataracts and sensorineural deafness. The May−Hegglin or Döhle-like inclusions are present in neutrophils, eosinophils and basophils. It has been stated that they are not present in monocytes2 but we and others3 have observed them. Inclusions are generally numerous and sharply defined, often spindle- or crescent-shaped, randomly distributed in the cell rather than near the cell margin, and more intensely staining than Döhle bodies. However the size and shape of the inclusions is dependent on the specific mutation present and sometimes they are small and round1. How clearly the inclusions are see is also dependent on the specific type of Romanowsky stain used; a May-Grünwald-Giemsa stain has been stated to be superior to a Wright stain in this regard1. At an ultrastructural level, inclusions differ from Döhle bodies, being composed of amorphous deposits of the mutant protein often incompletely surrounded by a single strand of rough endoplasmic reticulum or containing a few clusters of ribosomes and dense rods and spherical particles which are probably ribosomes. It is important to note that in some patients inclusions are not visualised by light microscopy but can be demonstrated by fluorescence microscopy with an antibody to MYH91, 2. The diagnosis of autoimmune thrombocytopenia should therefore always be made with circumspection in patients who have unusually large platelets, even in the absence of visible leucocyte inclusions.