Prion diseases are a rare type of neurodegenerative disease, and the sporadic Creutzfeldt-Jakob subtype is the most common. The disease occurs worldwide with an incidence of 1 case per million population per year. Prion protein (PrP) gene polymorphism without genetic mutation results in an aberrant protein isoform being deposited intraneuronally, leading to spongiform neuronal degeneration. We report on two patients who were admitted to our Service with systemic and neurological disease, with fatal end after 14 and 9 months of follow-up, respectively. Diagnosis was confirmed by histologic examination of the brain.

A case of nephrogenic metaplasia of the left ureter occurring in a 7-year-old male child, associated with recurrent urinary infection and previous surgical intervention, is described. This is to our knowledge the third reported case of this entity. Nephrogenic metaplasia involves the transitional epithelium of the urinary tract and results in the formation of structures histologically similar to renal tubules.

The case of a 3-month-old infant who died with an acute form of visceral leishmaniasis is reported. The liver presented an unusual pattern with widespread patchy cellular necrosis besides marked reticulin proliferation and some fibrosis. The marked systemic histiocytic proliferation contrasted with the paucity of Leishman-Donovan bodies, responsible for the negativity of two bone marrow aspirates and a needle biopsy of the liver. Visceral leishmaniasis must be considered in the differential diagnosis of cholestatic syndromes in infancy.