Allergic fungal sinusitis due to Curvularia lunata

The clinical and pathologic features of allergic fungal sinusitis caused by Curvularia lunata, as seen in two patients, are described. The findings are identical to those of allergic aspergillus sinusitis. Patients have allergies, nasal polyposis, and, occasionally, eosinophilia. Radiographs show opacification of multiple sinuses without bone destruction. Surgical specimens consist of polyps and inspissated, mucoid material. Diagnostic microscopic features, termed "allergic mucin," include eosinophils, numerous Charcot-Leyden crystals, and hyphae embedded in pools of mucus. The recognition of allergic mucin may be impeded by extensive degranulation and fragmentation of the eosinophils. In addition, the fragments of mucin exhibit large, poorly stained central areas, probably due to incomplete penetration by the fixative. Eosinophils are easier to recognize in well-fixed areas. Electron microscopy, though not of diagnostic necessity, confirms the eosinophilic nature of the infiltrate. It is important that surgical pathologists recognize this distinctive clinicopathologic entity and recommend appropriate cultures.