Histoplasmosis of the central nervous system: Report of two cases and review of the literature

Abstract

Two cases of central nervous system histoplasmosis, both fatal, are reported. Each is unusual because of the predominance of symptoms of central nervous system involvement. The first case represents the first report of a solitary histoplasmoma in the central nervous system. In a review of the English literature, from 1952 to 1960, 235 case reports of histoplasmosis meeting our stated criteria were found. The incidence of central nervous system involvement in this group was 7.4 per cent. Of the 235 cases disseminated disease was found in 32 per cent, and among the cases of disseminated disease the incidence of central nervous system involvement was 24 per cent. In the entire English literature twenty-six case reports of central nervous system histoplasmosis were found. The clinical and pathologic features of these cases are summarized. Neurologic signs and symptoms attributable to histoplasmosis were reported in six of the twenty-six cases. Each of these six patients had significant pathologic findings. Five patients with central nervous system histoplasmosis who had significant pathologic changes did not have neurologic symptoms. Fourteen patients with either mild meningitis or histiocytic histoplasmosis were neurologically asymptomatic. It is concluded that central nervous system involvement in histoplasmosis is often present subclinically. Cultures, biopsies of bone marrow, lymph nodes and ulcerating lesions, and complement fixation tests are shown to be valuable aids in diagnosis. On occasion cerebrospinal fluids have been reported as normal in the presence of significant clinical and pathologic changes. Skin test results were generally negative and, as such, were diagnostically misleading. A new classification in central nervous system histoplasmosis is formulated and includes (1) perivenous miliary granulomatosis, (2) parenchymal granulomatosis, (3) meningitis, (4) histoplasmoma, and (5) histiocytic histoplasmosis.