Résumé
Histoplasma capsulatum, a ground fungus, can infect humans, normally in endemic areas; the resulting disease can be asymptomatic or it can have a benign development, but in rare cases it can develop into a serious clinical condition and can even be fatal. Its most characteristic initial location is in the lungs, resembling tuberculosis, often accompanied by mediastinitis and an exuberant fibrotic response. The spread of this infection can be caused by the concomitance of another illness that alters the immunological balance. Sometimes such an association is not clear. Therefore, disseminated histoplasmosis is defined as a clinical condition where the fungus is present in more than one location. Common variable immunodeficiency is characterized by a generalized failure in the synthesis of antibodies, leading the affected individuals to present recurrent infections, especially those caused by encapsulated bacteria, most often involving the respiratory tract. We studied a serious case of disseminated histoplasmosis, accompanied by common variable immunodeficiency, observed at the Infirmary of the department of Medical Practice of the Federal University at Paraná Hospital das Clínicas