Ten-minute silver stain for Pneumocystis carinii and fungi in tissue sections.

A ten-minute methenamine silver staining procedure for the rapid demonstration of Pneumocystis carinii and fungi in tissue sections has been developed. The procedure is optimal for both urgent and routine histologic diagnosis of diffuse, progressive, and life-threatening pulmonary infiltrates, especially in the compromised host, and of fungal lesions in general. Moreover, it is simple and brief, is applicable to both paraffined and frozen sections, and can easily be used by the pathology resident or pathologist if the need arises. It consistently yields results that are far superior to those obtained by Grocott's original methenamine silver method, and as good as or superior to those of modified silver methods and such nonsilver procedures as Giemsa's, Gram-Weigert, and toluidine blue stains.