Pulmonary scintigraphy in fibrosing mediastinitis due to histoplasmosis

The pulmonary scintigraphic findings from four patients with fibrosing mediastinitis due to histoplasmosis are reported. The ventilation/perfusion (V/Q) mismatch mimicked pulmonary emboli. However, in these cases the chest radiographs and/or gallium-67 scintigraphy were abnormal, suggesting mediastinal or hilar disease. Awareness of the nonembolic conditions that can result in V/Q mismatches is important in the interpretation of lung scans.