Examination of Human Appendixes for Histoplasma Capsulatum

The reports of Raftery¹and Raftery, Trafas, and McClure²indicate a high incidence, 12.3% in children 16 years and younger and 5% in an unselected series, of organisms identified morphologically by them as Histoplasma capsulatum in patients'appendixes. These reports stimulated us to analyze our own material critically, since we had not noted H. capsulatum in our routine histological examinations of either appendixes or mesenteric lymph nodes. It was of special interest to us since we were dealing with patients in a presumably endemic area where disseminated cases are being recognized with regularity and the diagnosis substantiated by both histological and cultural methods without apparent difficulty. At the same time there is a high incidence, about 60%, of positive reactions to the histoplasmin skin test (Armstrong,³Christie and Peterson,⁴and Palmer⁵) in subjects who have no clinical evidence of the disease. MATERIALS AND METHODS Routine surgical