Occurrence of Histoplasma in Solitary Pulmonary Nodules in a Non-Endemic Area

Abstract

This paper deals with a pathologic study of 26 specimens of surgically resected, pulmonary, fibroscaseous granulomas, 20 of which contained organisms morphologically identified as Histoplasma capsulatum. Clinical data pertinent to the 20 positive specimens are summarized. The importance of considering histoplasmosis as the causal agent of roentgenographically diagnosed, solitary, pulmonary nodules is emphasized. The use of skin tests with histoplasmin is urged for the routine study of patients with solitary pulmonary nodules. Diagnostic study of nodules excised from the lung should include bacteriologic and also histochemical technics. The value of the methenamine-silver nitrate method (Grocott) for the demonstration of H. capsulatum in solitary nodules in the lung is favorably compared with results obtained by means of using the periodic acid-Schiff (PAS) stain.