It is often found in the apical posterior segment of the lower lobe, projecting over the hilum on a standard posteroanterior chest roentgenogram. Invasive pulmonary aspergillosis and pulmonary mucormycosis occur in patients with neutropenia or in patients with depressed neutrophil function, usually caused by high-dose glucocorticoid therapy. Alveolar cell carcinoma commonly presents as a slowly growing mass, often occupying most of a lobe or lung. The former, but not the latter, almost always displays hilar adenopathy, mediastinal adenopathy, or both. Intralobar sequestrations are located in the posterior basal segment adjacent to the diaphragm, and two of three sequestrations are located on the left.
Bronchogenic cysts can also present as large masses.