Cavitary pulmonary coccidioidomycosis: pathologic and clinical correlates of disease

Cavitary pulmonary coccidioidomycosis is a difficult diagnosis to establish due to the poor sensitivity of serological tests and rarity of culture from sputum. A pathologic and clinical analysis was performed of 21 consecutive patients with surgically resected cavities that proved to be coccidioidomycosis. Ten patients (48%) had serological evidence of Coccidioides infection, and 1 patient cultured Coccidioides spp. from sputum. The definitive diagnosis of coccidioidomycosis was made in the remaining 10 patients (48%) upon microscopic examination of tissue. The pleura showed fibrous pleuritis in 7 patients (33%) and eosinophilic pleuritis in 4 cases (19%); granulomas without microorganisms were demonstrated in 4 cases (19%). The cavity wall showed chronic inflammation and occasional giant cells but no granulomas and no microorganisms. The cavity contents included a mycetoma in 6 cases (28%); the cavity lining showed neutrophils and caseous necrosis; Coccidioides hyphae were present in 13 (62%) and spherules in 16 (76%) cases but often were rare. Adjacent lung showed lymphoid hyperplasia with chronic bronchiolitis in all cases; satellite granulomas with diagnostic spherules were variably present. The histopathology of cavitary coccidioidomycosis is strikingly variable depending on what area is sampled by biopsy, and microorganisms may be rare. This may explain the high rate of failure of diagnosis by fine needle aspiration and bronchoalveolar lavage. Pathologists in nonendemic areas must be aware of these findings, as this disease is now diagnosed worldwide.