Tricuspid valve blood cysts in infancy

Abstract

A 2.5 months old boy was found dead in bed with his mother. He had been delivered by normal vaginal delivery after an unremarkable pregnancy at 41 weeks gestation. His only significant history had been an admission to hospital for dehydration secondary to viral gastroenteritis at 7 weeks of age. Prior to his death he had a cough, wheezing and runny nose for several days, attributed to a viral upper respiratory infection. On the night of his death he had been taken to bed by his mother at approximately 0100 hours, fed at approximately 0330 hours and found unresponsive in a supine position at 1,100. He had last been seen alive in the supine position. At autopsy there was mild pulmonary congestion, mild pallor and mottling of the cut surfaces of the liver, reactive enlargement of cervical and paratracheal lymph nodes and turbid fluid within the left and right middle ear cavities. There were no signs of injury. A finding of note on the atrial surface of the tricuspid valve were two 0.5 mm diameter dark red nodules adjacent to the free margin of the mildly dysplastic valve (Fig. 1). Histologic evaluation of the lungs revealed congestion and mild edema with patchy post mortem bacterial overgrowth. Smaller bronchioles showed mild focal peribronchiolar infiltrates of mononuclear cells, variable numbers of neutrophils and occasional eosinophils. The lumina of the affected bronchioles contained necrotic cellular debris and occasional multinucleate syncytial epithelial cells. The appearances were of bronchiolitis in keeping with a viral infection. These changes were not severe and were seen in only some of the sections. There was also mild microvesicular steatosis of the liver and reactive follicular hyperplasia of lymph nodes. Neuropathological examination of the brain showed early hypoxic-ischemic changes with widespread granular b-amyloid precursor protein axonal immunoreactivity possibly related to the hypoxic-ischemic injury. Sections of the small nodules noted macroscopically on the tricuspid valve showed small cystic cavities within the valve leaflet adjacent to the free margin lined by flattened endothelium that contained degenerate red blood cells. The appearances were those of tricuspid valve blood cysts (Fig. 2). Bacteriological studies yielded mixed growths from the right lung, blood and left and right middle ears, in keeping with post mortem contamination. Virological studies