Pulmonary Adenocarcinoma Mimicking Pneumonia in a Young Adult

Abstract

Lung cancer is the third most common cancer in the United States. Lung adenocarcinoma is a subtype of non-small cell lung cancer. On computed tomography (CT) it can appear as ground glass nodules, consolidative opacity, or solid mass lesions located in the periphery. Because it can appear as a consolidation, it can sometimes be confused with an infectious process such as pneumonia. We present a case of a 27-year-old male initially diagnosed with pneumonia; however, three months later, when he presented to the hospital with worsening pleuritic chest pain, fever, and dyspnea after a bronchoscopy a week before admission, pathology was positive for adenocarcinoma.

Keywords: adenocarcinoma; histology; lung cancer; pneumonia; pneumonic adenocarcinoma.

Figure 1. Chest X-ray image

The image shows consolidation (blue arrow), nodularity (red arrow), hilar lymph node (yellow arrow).

Figure 2. Chest X-ray showing consolidation

Blue arrows show right and left lung consolidation.

Figure 3. Computed tomography chest (axial images)

The red arrow shows consolidation and the blue arrow shows evolving abscess.

Figure 4. Computed tomography images of extensive multifocal pneumonia with dense right upper lobe and left lower lobe consolidation

Multiple areas of breakdown and evolving abscesses within the consolidated left lower lobe (blue arrow). Numerous bilateral pulmonary nodules with cavitating nodules in the left lobe (red arrow).

Figure 5. Histology (right upper lobe lung)

Transbronchial biopsy reveals adenocarcinoma with mucinous features consistent with invasive mucinous carcinoma.

Figure 6. PET images

PET: Positron emission tomography PET scan image shows increased tracer uptake (blue arrows).