Surgical pathology of pleural coccidioidomycosis: a clinicopathological study of 36 cases

SummaryMost pulmonary coccidioidal infections are intraparenchymal; the pleurae are rarely involved. Pleuritis is a recognized complication of ruptured cavitary infections and occasionally occurs in other settings but has not been fully characterized. To define the clinical and histopathologic characteristics of pleural coccidioidomycosis as encountered by surgical pathologists, we reviewed the clinical history, imaging, and histology of 36 biopsy-, resection-, or autopsy-confirmed cases (with coccidioidal spherules present in pleural tissue; median age, 39 years; 22 men). These represented 7% of all pulmonary coccidioidal infections and showed 2 modes of presentation, including ruptured cavitary infection (26) and pleural-predominant disease with milder parenchymal involvement (10). Risk factors included immunodeficiency, smoking, and occupational exposure to soil. Common symptoms (median, 5 weeks) included cough (47%), chest pain (44%), and dyspnea (39%). Imaging often showed pleural adhesions (64%) and effusions (61%). Treatment included lobectomy or decortication, with antifungal medications. All cases showed granulomatous pleuritis. Both modes of presentation showed similar histologic features, including the composition of inflammatory infiltrates, degree of fibrosis, and extent of necrosis. Spherules were usually few (mean density, <1/10 high-power field). Three deaths occurred (all with ruptured cavities); the remaining patients recovered. Differential diagnosis of pleural effusions should include coccidioidomycosis, particularly in endemic areas, even without significant intrapulmonary disease. Most cases of coccidioidomycotic pleuritis are encountered by pathologists after resection of ruptured cavities with decortication, but pleural-predominant infections may be biopsied for diagnostic purposes. Spherules are usually rare in pleural tissue, and liberal sampling, cultures, or serologic studies may be required to confirm the diagnosis.