Pulmonary mass in tachypneic, febrile adult

Radiographic Imaging of Community-Acquired Pneumonia: A Case-Based Review

The chest radiograph is the most common imaging examination performed in most radiology departments, and one of the more common indications for these studies is suspected infection. Radiologists must therefore be aware of less common radiographic patterns of pulmonary infection if they are to add value in the interpretation of chest radiographs for this indication. This review uses a case-based format to illustrate a range of imaging findings that can be associated with acute pulmonary infection and highlight findings that should prompt investigation for diseases other than community-acquired pneumonia to prevent misdiagnosis and delays in appropriate management.

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.

A case of round pneumonia due to Enterobacter hormaechei: the need for a standardized diagnosis and treatment approach in adults

Round pneumonia is an unusual radiological manifestation of a bacterial lung infection. We present the case of an elderly male patient who arrived at the emergency room with a productive cough and exertional dyspnea. His chest x-ray and CT showed a round opacity and air bronchograms in the right upper lobe. Taken together, the patient's symptoms and images strongly suggest a pulmonary infection. Empirical antibiotic therapy with ceftriaxone and clarithromycin was started. The sputum culture was positive for Enterobacter hormaechei and the bacterium was sensitive to levofloxacin; therefore, the antibiotic therapy was changed. Despite the treatment, the patient progressed to respiratory failure and septic shock, dying six days after admission. Although round pneumonia is uncommon, it is a potentially curable disease and clinicians should always consider it in their differential diagnosis.

An unusual case of lung abscess secondary to round pneumonia caused by recurrent Klebsiella pneumoniae strain and the role of occult metastases tumor

Round pneumonia is an uncommon form of community-acquired pneumonia usually found in children. To this date, there has been no report on local pulmonary complications in this entity in adult patients. The present study reports a case of a 77-year-old male with lung abscess secondary to round pneumonia caused by recurrent Klebsiella pneumoniae infection accompanied by occult metastases tumor. Occult metastases may have played an important role in leading to cavity as in this present case. Further investigation regarding the relationship between recurrent infection and metastases is needed.

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

BACKGROUND AND AIMS

Round pneumonia (RP) is a rare radiological presentation of a subtype of lobar pneumonia that arises because of a developmental defect in connective tissues (pores of Köhn and channels of Lambert). The round appearance on chest X-ray (CXR) is thought to occur from an infectious process that spreads from small peripheral alveoli centrifugally through interalveolar channels via the pores of Kohn and the canals of Lambert. This explains the nonsegmental distribution and shape of RP. The pathogenesis of RP is unknown. An alternative theory holds that RP in children occurs because of underdeveloped pores of Kohn and the absence of canals of Lambert, limiting the spread of the organism and resulting in a focal, round mass seen on radiographs. As a result of this developmental defect, dissemination of infection remains in a limited area. While this is a well-known entity in childhood, it has been described infrequently in adults. Lesions of RP are not necessarily round; oval lesions can also be seen. It is a radiological subtype of the pneumonia subtype and presents as a solitary nodule or a mass lesion in CXR.

METHODS

We presented two cases of RP. One mimicked and was mistaken for pulmonary infarction because of triangular pleural-based density and the other mimicked pulmonary malignancy because of a homogeneous triangular opacity based on the pleura on the posteroanterior radiography and computed tomography.

CONCLUSION

These cases were presented because of RP's importance, and RP should be considered a part of differential diagnosis of pulmonary infarct and lung tumor.

Round pneumonia: a rare condition mimicking bronchogenic carcinoma. Case report and review of the literature

CONTEXT

Round pneumonia is a condition usually described in children, with few reports addressing adult patients. It is an oval-shaped consolidation that, due to its radiological appearance, simulates bronchogenic carcinoma. Its evolution tends to be benign, although diagnostic dilemmas have sometimes required exploratory thoracotomy. Deaths caused by this condition have even been reported. To the best of our knowledge, there have been 31 previous cases of round pneumonia in adults reported in the English and Portuguese-language literature, of which only one was completely asymptomatic.

CASE REPORT

The case of a 54-year-old female patient presenting a lung mass found on routine imaging evaluation is reported. Respiratory symptoms and signs were absent, but the patient had a significant history of smoking. Her physical examination gave normal results. On chest radiographs, a mass located in the middle third of the right lung was observed. Three weeks after the initial evaluation, the patient was admitted for a complete evaluation and for staging of a pulmonary malignancy, but repeated chest radiographs showed complete resolution.

Round pneumonia in children

We evaluated four children with rounded densities on their chest radiographs in whom the final diagnosis was presumed to be lower respiratory tract infection. The differential diagnose between round pneumonia and a neoplastic process is difficult to make. In this report, all of cases of round pneumonia have resolved clinically and radiographically with antibiotic therapy.

Round pneumonia: imaging findings in a large series of children

BACKGROUND

Although round pneumonia is a well-known clinical entity, there have been no large case reviews, with most knowledge based on case reports and small series from the 1960s and 1970s.

OBJECTIVE

To review the imaging findings of a large series of children with round pneumonia.

MATERIALS AND METHODS

A retrospective review of radiographic and CT findings in all children reported to have round pneumonia at a large children's hospital from 2000 to 2006 was performed. Children with underlying medical conditions were excluded. Epidemiologic characteristics, radiographic and CT findings, and follow-up imaging were reviewed.

RESULTS

The review identified 109 children (mean age 5 years, range 4 months to 19 years). Round pneumonias tended to be solitary 98% (107/109), have well-defined borders 70% (77/109), and be posteriorly located 83% (91/109), with the following lobar distribution: left lower lobe (36), right lower lobe (33), right upper lobe (28), left upper lobe (7), right middle lobe (4), and lingula (2). Round pneumonia tended to resolve on follow-up imaging (95%, 41/43) as compared to progression to lobar pneumonia (4.6%, 2/43). Three patients (2.6%, 3/112) originally suspected to have round pneumonia were later shown to have other diagnoses: cavitary necrosis in pneumonia (two) or pleural pseudocyst (one).

CONCLUSION

Round pneumonia occurs in young children (mean age 5 years), tends to be a solitary lesion, and is most commonly posteriorly located. Misdiagnosis of other pathology as round pneumonia is uncommon.