Case of round pneumonia: pulmonary infarct and a rare situation that is similar with the lung cancer

Spherical pneumonia caused by Ralstonia mannitolilytica: a case report and literature review

BACKGROUND

Spherical pneumonia is an extremely rare condition that is difficult to diagnose. It is a specific type of lung infection that often manifests as a round or round-like mass on chest imaging. Spherical pneumonia is easily misdiagnosed as a pulmonary tumor; therefore, awareness of this disease must be strengthened.

CASE PRESENTATION

The patient was a 29-year-old female who had persistent cough and sputum for approximately 1 month and fever for 5 days. Chest computed tomography (CT) at our hospital revealed a mass in the lower lobe of the right lung near the hilar region, with obstructive pulmonary atelectasis and obstructive pneumonia. Although lung cancer was suspected, Ralstonia mannitolilytica was detected by metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid, and no cancer cells or Mycobacterium tuberculosis were detected. Finally, the patient was diagnosed with spherical pneumonia caused by R. mannitolilytica. Anti-infective treatment, symptomatic treatment, and administration of a traditional Chinese medicine decoction were performed based on the syndrome differentiation. After 10 days of treatment, chest CT revealed few lesions in the lower lobe of the right lung, which were significantly reduced compared with those in the past.

CONCLUSIONS

Spherical pneumonia caused by R. mannitolilytica has not yet been reported and differential diagnosis is key in clinical diagnosis. When spherical pneumonia is difficult to diagnose, mNGS may be a better alternative.

Pulmonary infarction mimicking a lung mass: a case report

Pulmonary infarction usually appears as a wedge-shaped opacity with its base placed laterally. Rarely, pulmonary infarctions may appear as a well-defined rounded opacity mimicking lung cancer and surgical lung biopsy may often be required for definitive diagnosis. We report a patient who was admitted with submassive pulmonary embolism who had an incidental finding of a well-defined opacity in computed tomography (CT) scan. The lesion was avid on positron emission tomography (PET) scan and the patient was a smoker. So, we investigated him further with a percutaneous and later a thoracoscopic lung biopsy. Tumour-like pulmonary infarction is often a challenge for the clinicians.