Fine-needle aspiration biopsy of thoracic coccidioidomycosis: a single-institutional series of 101 cases.

INTRODUCTION

Coccidioidomycosis is a fungal infection endemic to the southwestern United States, particularly Arizona. Fine needle aspiration biopsy (FNAB) is established as effective in diagnosing infectious diseases. However, existing literature evaluating FNAB of thoracic coccidiomycosis remains limited. We present a large single institution series of thoracic coccidioidomycosis cases diagnosed through FNAB.

MATERIALS AND

METHODS

The Mayo Clinic Arizona Pathology database was searched for all FNAB cases with a diagnosis of coccidioidomycosis from January 1, 2013, to December 31, 2025. Electronic medical records were reviewed to tabulate demographics, clinical history, serology, and radiologic findings. All key cytologic, histologic, and special stained slides were reviewed.

RESULTS

One-hundred and one FNAB samples were obtained from 100 patients: 37 cases combined endobronchial ultrasound-guided transbronchial needle aspirate (EBUS-TBNA) and robotic-assisted bronchoscopy (RAB), 31 cases RAB, 20 cases EBUS-TBNA, 12 cases percutaneous computed tomography-guided, 1 case endoscopic ultrasound-guided. Coccidioides organisms were identified during rapid on-site evaluation in 34 cases, saving 18 patients from unnecessary procedures. Coccidioides organisms were identified in 94.1% (95/104) of cytology slides and in 67.1% and 66.7% of tissue biopsies and cell blocks, respectively. For the 6 cases without Coccidioides organisms on cytology slides, concurrent tissue biopsies or cell blocks with or without Grocott's methenamine silver stains helped confirm the diagnosis. Of the 41 patients with a malignancy history, one had both Coccidioides and malignancy in the same specimen.

CONCLUSIONS

FNAB is accurate at diagnosing thoracic coccidioidomycosis when combined with EBUS-TBNA and RAB. Rapid on-site evaluation is critical during interventional procedures and can eliminate the need for unnecessary procedures.