Coccidioidomycosis Mimicking Lung Malignancy

Document Type

Conference Proceeding

Publication Date

10-2025

Publication Title

Chest

Abstract

INTRODUCTION: Pulmonary nodules and masses have a wide differential diagnosis, with malignancy being the most concerning. While there is a high possibility for malignancy, it is important to consider other etiologies during the work-up of a pulmonary nodule or mass. Coccidioidomycosis is a fungal infection that can result in a wide array of clinical symptoms, ranging from asymptomatic infection to fatal infection [1, 2]. We describe a case with a clinical picture consistent with pulmonary malignancy; however, further investigation led to the diagnosis of pulmonary coccidioidomycosis. CASE PRESENTATION: An 80-year-old African American male with COPD, CAD s/p AICD placement, paroxysmal atrial fibrillation, history of pulmonary embolism on warfarin, OSA on CPAP, CKD, type 2 diabetes mellitus, and prostate cancer treated with radiation in the past presented to the emergency department with shortness of breath, cough, fatigue, and increased sputum production. The patient's social history was significant for a 35-pack-year smoking history. Vitals were stable on arrival. Labs were remarkable for a d-dimer of 1064. A CTA PE study revealed a mass-like opacity in the left upper lobe (LUL) measuring approximately 7.2 x 5.0 x 4.6 cm, which was new from a CT study two months prior. The patient was treated for a presumed COPD exacerbation and was discharged and advised to follow up for repeat imaging in four weeks. The patient returned three weeks later with worsening fatigue and shortness of breath with exertion and unintentional weight loss. A noncontrast CT chest was obtained, showing an evolving LUL mass, now measuring at 11.4 x 6.2 cm with innumerable new bilateral pulmonary nodules and mediastinal lymphadenopathy, highly suspicious for malignancy. Further evaluation with pulmonology and oncology then ensued. The patient underwent a bronchoscopy with EBUS which showed a LUL endobronchial tumor with greater than 90% obstruction in the apical-posterior segment with purulent material noted during the debulking process. Histopathology was significant for multinucleated giant cells with GMS stain-positive spherules, most consistent with coccidioidomycosis, and no signs of malignancy. Further questioning revealed the patient lived in the Mojave desert for 18 months, two years before this presentation and began to experience pulmonary symptoms after his return. The patient was initiated on fluconazole 400 mg daily and completed a nine-month course with a resolution of his mediastinal lymphadenopathy and a decrease in the size of the LUL opacity with no evidence of malignancy. DISCUSSION: Coccidioidomycosis is a dimorphic fungus endemic to southwest United States [1]. It has a broad spectrum of clinical manifestations, ranging from asymptomatic to fatal [1]. While most infections are asymptomatic, symptomatic patients are commonly misdiagnosed with community-acquired pneumonia [1, 2]. In our case, the patient received high dose steroids at a previous hospitalization, which likely caused worsening immunosuppression, leading to the patient's thin-walled coccoidal cavity to rupture, resulting in his severe pulmonary disease state eventually leading to the diagnosis of coccidioidomycosis. CONCLUSIONS: This case emphasizes the importance of maintaining a broad differential diagnosis when managing patients with CT findings suspicious of pulmonary malignancy and using a thorough social history to guide medical decision-making.

Volume

168

Issue

4S

First Page

1907A

Comments

American College of Chest Physicians CHEST Annual Meeting, October 19-22, 2025, Chicago, IL

Last Page

1908A

DOI

10.1016/j.chest.2025.07.1081

Link to Full Text

Share

COinS