Question 3
{"accessible":false,"alternatives":[{"id":9,"text":"bronchogenic cyst"},{"id":10,"text":"fungal infection"},{"id":11,"text":"lung metastasis"},{"id":13,"text":"neuroblastoma"},{"id":12,"text":"round pneumonia"}],"archived":false,"correctAlternativeId":12,"explanation":"\u003cp\u003eRound pneumonia refers to a rounded area of infective consolidation. Numerous theories about the formation of the rounded shape exist, but the most widely held view is that collateral pathways between alveoli (pores of Kohn and canals of Lambert) have not yet developed in many children and this limits the spread of infection. Hence, the infective area appears rounded. The infective agent is bacterial, with the most common causative agent being\u0026nbsp;\u003cem\u003eStreptococcus \u003c/em\u003e\u003cem\u003epneumoniae\u003c/em\u003e. Diagnosis allows early treatment of the infective agent and limits further investigation.\u003c/p\u003e\u003cp\u003eAir bronchograms may occur, and while this helps to clinch the diagnosis, they are not always seen. Bronchogenic cysts tend to contain fluid and appear as rounded, well-defined soft tissue density structures that cause local compression. Fungal infections and lung metastases can cause atypical appearances but the features described in the vignette are typical for round pneumonia. Neuroblastomas are malignant tumors that arise from the sympathetic chain\u0026nbsp;with 20% occurring within the posterior mediastinum, but the mass described here is not mediastinal.\u003c/p\u003e","id":3,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/2205","nextQuestionPath":null,"relatedArticles":[{"id":1722,"title":"Neuroblastoma","link":"/articles/neuroblastoma?lang=us"},{"id":8374,"title":"Bronchogenic cyst","link":"/articles/bronchogenic-cyst?lang=us"},{"id":7330,"title":"Round pneumonia","link":"/articles/round-pneumonia-1?lang=us"},{"id":32147,"title":"Pulmonary fungal disease","link":"/articles/pulmonary-fungal-disease?lang=us"}],"alsoUsedIn":[{"id":446,"kind":"Course","title":"Help: Multiple Choice Questions - page 446","link":"https://radiopaedia.org/courses/help-multiple-choice-questions/pages/446"}],"stem":"\u003cp\u003eA 7-year-old boy is brought to the A\u0026amp;E department with a cough and shortness of breath. There has been some history of fever, but no systemic upset. The chest radiograph reveals an ovoid opacity in the right mid-zone. The edges of the lesion are well defined. There are\u0026nbsp;no air bronchograms. What is the most likely diagnosis?\u003c/p\u003e","menuLinks":[{"text":"Report problem with question","url":"https://docs.google.com/forms/d/e/1FAIpQLSfO3soWYhOjJ7yErSysyCe5V4A1CqW7WK3rDA7MtAkecMGqNw/viewform?entry.1624461248\u0026entry.553583435=https://radiopaedia.org/questions/3"}],"attemptsPercentages":[{"alternativeId":"10","percentage":5},{"alternativeId":"13","percentage":5},{"alternativeId":"11","percentage":2},{"alternativeId":"9","percentage":27},{"alternativeId":"12","percentage":61}],"promptToLogin":false,"questionManager":false,"articleId":"pulmonary-metastases"}