Histopathological techniques for diagnosing cryptococcosis due to capsule-deficient Cryptococcus: case report

A case of cryptococcosis due to capsule- deficient Cryptococcus is presented, in which culturing of the clinical specimen and tests for capsular antigen in cerebrospinal fluid and serum were negative. The histopathological techniques evaluated were hematoxylin- eosin, Grocott methenamine silver, Mayer's mucicarmine and Fontana- Masson. The diagnosis of cryptococcosis due to capsule- deficient Cryptococcus was confirmed by means of the Fontana- Masson technique and by direct immunofluorescence. The potential of the histochemical techniques is discussed.