Radiological Category Thoracic Chest Principal Modality 1 CT

Radiological Category: Thoracic Chest Principal Modality (1): CT Principal Modality (2): None Case Report #0566 Submitted by: Alan Xu, M. D. Faculty reviewer: Emma Ferguson, M. D. Date accepted: 15 February 2009

Case History 3 month old with an outside prenatal ultrasound demonstrating a lung abnormality. Patient is here for further evaluation.

Radiological Presentations

Radiological Presentations

Radiological Presentations

Radiological Presentations

Test Your Diagnosis Which one of the following is your choice for the appropriate diagnosis? After your selection, go to next page. • Intralobar pulmonary sequestration • CCAM Type III • Congenital lobar emphysema

Findings and Differentials Findings: Multiple large cysts in the right lower lobe. Differentials: • Intralobar pulmonary sequestration • CCAM Type III • Congenital lobar emphysema

Discussion Intralobar sequestration consists of nonfunctioning pulmonary tissue that is supplied by anomalous arteries from the aorta and drains to pulmonary veins. The images shown in this case do not demonstrate such vascular supply or draining vein. Therefore, intralobar sequestration is not a likely diagnosis. Congenital lobar emphysema is the progressive overdistension of one or more lobes in the lungs. Causes in most cases are idiopathic but can include instances that lead to obstruction of the airways such as mucus impaction or extrinsic compression. On imaging, there is hyperlucency of the involve lobe(s). While there are hyperlucencies seen in the images presented in this case, a careful examination shows that the hyperlucencies are due to multiple large cysts; this makes congenital lobar emphysema a less like choice. Both CCAM Types 2 & 3 consists of cysts. However, in CCAM Type 3, the cysts are so small that they are not discernible and this type of CCAM will appear on imaging as a homogenous mass. In the images provided, one can clearly identify individual cysts in the pulmonary parenchyma which makes CCAM Type 3 an incorrect choice. This leaves CCAM Type 2 as the correct answer.

Diagnosis Congenital Cystic Adenoid Malformation Type II

References 1. Weissleder R, Wittenberg J, Harisinghani M, Chen J. Primer of Diagnostic Imaging. 4 th Edition. 2007 (Pg 831)