Acute İnterstitial Pneumonia Associated with Spontaneous Pneumothorax

Clinical History

A 22 year old female patient presented to the emergency unit with a sudden onset of cough and dyspnea.

Imaging Findings

There was no history of exposure to toxic agents; nor had the patient takenany drugs. The patient was reportedly non- smoker and there was no recent history of contact with house hold pets (cats, dogs or birds). Initial chest x-ray radiograph displayed diffuse patchy alveolar densities. CT scan showed bilateral diffuse septal interstitial thickening, ground glass appearance and areas of irregular patchy consolidation (fig.1). In addition bronchovasculer structures were distorted and traction bronchiectasis and right sided pneumothorax was evident (fig.2). The patient did not respond to 10 days of antibiotic and supportive treatment. After bronchoscopic biopsy and bronchioalveolar lavage yielded nonspesific results open lung biopsy was performed reporting non specific interstitial pneumonia. Follow – up HRCT performed after 2 weeks displayed decreased alveolar infiltration and predominance of interstitial findings. Moreover, bilateral cystic lesions had developed along with a bullous lesion within the right upper lobe (fig.3).

Discussion

Acute interstitial pneumonia (AIP) is an idiopathic lung disease characterised by rapidly progressive dyspnea developing over days to weeks. AIP is synonymous with Hamman Rich syndrome. It is defined as rapidly progressive respiratory failure occuring in patients without pre-existing lung disease or extrathoracic disorders known to be associated with lung involvement. Patients with AIP have a poor prognosis, with reported mortality rates of 60-100%. The pathologic hallmark of AIP is diffuse alveolar damage. Histopathological investigation is always necessary for a definitive diagnosis of AIP.The chest radiographic and high-resolution CT scan manifestations of AIP are bilateral and sometimes patchy, and there are alveolar densities associated to areas of ground glass attenuation. But these findings are nonspecific. Acute onset is a very important clue in the diagnosis of AIP. Traction bronchiectasis, bronchioloectasis, fibrosis and cysts (honey combing) develope with time. AIP is considered among idiopathic interstitial pneumonias.This kind of diseases are reported to occasionally develop acute complications such as pneumothorax and pneumomediastinum. If CT displays paranchymal and interstitial findings coupled with pneumothorax the initial differential diagnosis should include brochiolitis obliterans,AIP, idiopathic pulmonary fibrosis group disease, cystic fibrosis, langerhans cell histiocytosis, lymphangiomyomatosis, hypersensitivity pneumonia and pneumocysts jirovecii pneumonia.

Differential Diagnosis List

Final Diagnosis

Acute interstitial pneumonia

URL:	https://www.eurorad.org/case/5288
DOI:	10.1594/EURORAD/CASE.5288
ISSN:	1563-4086