An unusual cause of photographic negative of pulmonary edema: Sarcoidosis.

A 38-year-old male was admitted with complaints of fever, dry cough and progressive breathlessness of 6-week duration. His medical history was unremarkable.

On admission, he was febrile, with a temperature of 38.8°C. His pulse was 108 beats/min, blood pressure was 148/94 mmHg and respiratory rate was 30 breaths/min, with a room air saturation of 90%. Respiratory examination revealed bilateral diffuse fine inspiratory crackles. The rest of the physical examination was unremarkable.

His routine investigations did not reveal any abnormality. The chest X-ray showed bilateral dense peripheral opacities with ill-defined margins without any segmental distribution [Figure 1]. High-resolution computed tomography of the chest revealed peripheral, subpleural confluent ground glass haze and consolidation in the middle and lower lobes [Figure 2].

Figure 1

Chest radiograph showing bilateral peripheral opacities

Figure 2

High-resolution computed tomography of the chest showing bilateral peripheral air-space disease

QUESTION

What is your differential diagnosis?

ANSWER

Chronic eosinophilic pneumonia

Bronchiolitis obliterans organizing pneumonia,

Radiation injury to the lung

Sarcoidosis.

Broncho-alveolar lavage revealed lymphocytosis and normal screens for AFB, fungus and pyogenic organisms. Transbronchial lung biopsy revealed non-caseating compact granulomas [Figure 3]. His serum angiotensin-converting enzyme levels were 104 IU (normal range, 0–50 IU). Diagnosis of sarcoidosis was made and the patient was started on oral prednisone at 30 mg/day. There was dramatic clinico-radiological improvement. His temperature and dyspnea improved within 5 days and pulmonary infiltrate cleared in 2 weeks.

Figure 3

Histopathology revealing compact non-caseating granulomas on hematoxylin and eosin, ×40

The typical radiographic pattern of predominantly peripheral consolidation was first described by Gaensler and Carrington as “the photographic negative of pulmonary edema,” and is considered to be characteristic of chronic eosinophilic pneumonia (CEP).[1]

Pulmonary parenchymal opacities occur in 25–50% of sarcoid patients. They are typically bilateral and symmetric with central and upper lobe predominance. Bilateral peripheral opacities rarely occur in sarcoidosis.[2]

Other causes of reverse pulmonary edema pattern include bronchiolitis obliterans organizing pneumonia (BOOP), sarcoidosis, Churg-Strauss syndrome, bronchioloalveolar carcinoma (BAC) and focal radiation injury of the lung.

LEARNING POINTS

Besides CEP, photographic negative of pulmonary edema can result from myriad of causes like BOOP, sarcoidosis, Churg-Strauss syndrome, BAC and focal radiation injury of the lung.

Early bronchoscopy with Bronchoalveolar Lavage and Transbronchial Lung Biopsy helps to differentiate the above conditions.