Unusual forms of immature sporulating Coccidioides immitis diagnosed by fine-needle aspiration biopsy.

Coccidioidomycosis is an endemic infection acquired by inhalation of the spores (arthroconidia) of the thermally dimorphic fungus, Coccidioides immitis. The arthroconidia transform into spherical cells called mature spherules in the lung. Immature spherules and other atypical forms of immature C immitis have rarely been found in vivo. We report on a case that presented unusual forms of immature sporulating C immitis in a fine-needle aspiration specimen. A 36-year-old Chinese woman, living in New Jersey for the past 10 years, presented with fever, night sweats, hemoptysis, and an abnormal chest radiograph approximately 9 months after a brief vacation trip to the Grand Canyon in Arizona. She was treated with antibiotics for 4 weeks without improvement. Subsequent chest computed tomography showed a 3-cm cavitary lesion in the right lower lobe of the lung. Fine-needle aspiration biopsy revealed diverse morphologic forms of a fungus that was confirmed by culture as immature sporulating C immitis.