Mounier-Kuhn syndrome masquerading pulmonary thromboembolism in an elderly male
A 70-year-old male presented with shortness of breath for 3 days. There was associated mild non-productive cough. Patient had a past history of episodes of cough with expectoration and fever on several occasion. However, the patient had never suffered such a severe respiratory embarrassment in the past. On examination, there was tachycardia (heart rate of 100 bpm), tachypnea (respiratory rate was 25/min) with SpO2 85% and FiO2 50%. Patient was afebrile and blood pressure was within normal range (measured on at least three occasions). On general physical examination, the patient had pallor. However, there was no cyanosis, clubbing or pedal edema. Cardiorespiratory examination was significant for bilateral crepitations and occasional bronchial breath sounds. The heart sounds were normal. Hemogram revealed mild anemia (hemoglobin 11.5 g%). However, the total and differential leukocyte counts as well as platelet counts were normal. Routine biochemical tests including renal and liver function tests were normal. Chest radiograph (CXR) revealed patchy areas of bronchiectasis in both lungs. In addition, there were fibrotic opacities, more on the right side []. Echocardiography revealed dilatation of the right atrium (RA) and ventricle (RV). Associated findings included decreased contractility of RV and moderate tricuspid regurgitation. A diagnosis of acute pulmonary thromboembolism (PTE) was suggested. Doppler ultrasound evaluation of bilateral lower limbs was negative for deep venous thrombosis. Well's pre-test probability score was 4.5 (pulmonary embolism more likely than alternate diagnosis and heart rate more than 100). CT pulmonary angiography (CTPA) was subsequently performed to establish the diagnosis. CTPA excluded the diagnosis of acute PTE; however, high resolution CT reconstructions revealed massive enlargement of trachea (maximum diameter of 33 mm) and right main bronchus (maximum diameter of 25 mm) with evidence of tracheal and bronchial diverticula. There was extensive bronchiectasis involving the right upper lobe with peripheral fibrotic opacities suggestive of parenchymal scarring [Figures and ]. The main pulmonary artery was dilated. Further, the echocardiography findings of dilatation of RA and RV were confirmed. The pulmonary artery hypertension (PAH) was explained to be due to extensive parenchymal disease. Retrospective evaluation of a CXR done 1 year back revealed tracheabronchomegaly. The lung fields were unremarkable. Thus, a diagnosis of tracheabronchomegaly with bronchiectasis and PAH was made and patient was put on oxygen therapy and chest physiotherapy.