Intravascular calcium deposits in a critically ill patient. Light- and electron-microscopic findings

We describe a case of a 2-year-old girl with an unusual finding of amorphous hematoxyphilic substance in the pulmonary and myocardial vascular lumina. The patient had a prolonged history of intestinal obstruction necessitating extended periods of total parenteral nutrition. The patient terminally had hypercalcemia with levels reaching 4.63 mmol/L. The intravascular substance stains strongly positive for calcium, and weakly positive for fibrin. Electron microscopy shows that the substance has a distinctive configuration suggestive of calcium hydroxyapatite crystals.