Bronchiolitis obliterans organizing pneumonia: experience at three hospitals in Riyadh

Because reports of bronchiolitis obliterans organizing pneumonia (BOOP) are lacking from the Middle East, we conducted a retrospective review of of all histopathologically proven cases of BOOP over a 10-year period at three tertiary care hospitals in Riyadh and describe the clinical features and outcome.

Charts at the three hospitals were searched using a specific code for BOOP or cryptogenic organizing pneumonia (COP). Lung specimens had to show histological proof of BOOP with a compatible clinical picture. Chest radiographs and high-resolution CT scans were reviewed.

Twenty cases of biopsy-proven BOOP had well-documented clinical and radiographic data. There were 11 males and 9 females (mean age, 58 years; range, 42-78). The clinical presentation of BOOP was acute or subacute pneumonia-like illness with cough (85%), fever (70%) dyspnea, (85%) and crackles (80%). The most frequent radiological pattern was a bilateral alveolar infiltrate. The most common abnormality on pulmonary function testing (n=14) was a restrictive pattern (11 patients). Most patients (70%) had no underlying cause (idiopathic BOOP). Other associations included thyroid cancer, rheumatoid arthritis, syphilis and Wegner's granulomatosis. Ten patients (50%) had a complete response to steroids, 6 (30%) had a partial response and 3 (15.8%) with secondary BOOP had rapid progressive respiratory failure and died.

The clinical presentation of BOOP in our patients is similar to other reported series. A favorable outcome occurs in the majority of cases. However, BOOP may occasionally be associated with a poor prognosis, particularly when associated with an underlying disease.