Cryptococcus within a urinary cast

Abstract

A 13-year-old girl with AIDS was admitted to the hospital with neck pain and vomiting. Routine urinalysis revealed an unusual cast containing two encapsulated budding yeast forms entrapped within the matrix (Figure 1). The urine sediment was stained with China ink and revealed free encapsulated budding yeasts (Figure 2). The morphology of the yeast was consistent with Cryptococcus sp. The fungus was also isolated in the cerebrospinal fluid (CSF) and in liver and bone marrow biopsy, characterizing disseminated cryptococcosis. The latex agglutination test was positive in the serum (titer 1:4096). The patient is currently on treatment for the cryptococcal infection with amphotericin B. The diagnosis of disseminated cryptococcosis is usually made by CSF analysis. Urine is an easy-to-obtain sample that may be useful in a search for Cryptococcus sp. Although reports describing cryptococcuria exist, this is the first report of Cryptococcus sp. being entrapped within a urinary cast. Urine microscopy and culture could provide important clues to the presence of cryptococcal infection. n e p h r o l o g y i m a g e http://www.kidney-international.org