Bilateral Pleural Effusion in Cryptogenic Organizing Pneumonia: A Case Report and Review of Atypical Presentations.

Cryptogenic organizing pneumonia (COP) is a rare form of idiopathic interstitial lung disease that often presents with non-specific respiratory symptoms and radiographic findings that mimic infectious pneumonia. Due to these overlapping clinical features, COP is frequently misdiagnosed, leading to delays in appropriate management. We report the case of a 23-year-old female patient who presented with dyspnea, productive cough, and fever. Despite receiving broad-spectrum antimicrobial therapy, there was no clinical or radiographic improvement. Imaging revealed bilateral pulmonary opacities and pleural effusions, and diagnostic bronchoscopy with transbronchial biopsy confirmed organizing pneumonia. Secondary causes, including infections, autoimmune diseases, and malignancy, were excluded. The patient started on oral prednisolone, resulting in significant improvement in both symptoms and radiological findings. This case underscores the importance of considering COP in patients with non-resolving pneumonia, particularly when there is no response to adequate antibiotic therapy. A combination of radiological assessment, histopathological confirmation, and exclusion of secondary causes is essential for accurate diagnosis. Clinicians should maintain a high index of suspicion for COP in such scenarios, as timely diagnosis and initiation of corticosteroid therapy are critical for symptom resolution and prevention of disease progression.