Correct!
4. The imaging appearance of the lesion is consistent with an arteriovenous malformation
The imaging appearance of the right middle lesion is diagnostic of pulmonary arteriovenous malformation. When a tubular opacity is seen at chest radiography, either abnormal vessels (arteries, as part of arteriovenous malformations, or, even more rarely, veins, in the context of a pulmonary varix or anomalous pulmonary venous drainage) or dilated, impacted bronchi should be considered as possibilities accounting for the tubular morphology. When dilated, impacted bronchi are present, bronchiectasis with impaction, as could occur in the context of allergic bronchopulmonary aspergillosis, should be considered. However, the airways in this patient are completely normal; therefore, no evidence of allergic bronchopulmonary aspergillosis is present. The large associated vessels and intense enhancement of the nodule are inconsistent with pulmonary malignancy, either primary or metastatic, even when considering vascular tumors, such as carcinoid tumor, glomus tumor, or vascular metastases, such as renal cell carcinoma, choriocarcinoma, and melanoma. Pulmonary artery aneurysm should be a consideration when an intensely enhancing nodule associated with vessels is detected at CT, but aneurysms present as either fusiform or saccular dilations of a pulmonary artery, rather than an intensely enhancing nodule associated with an enlarged artery, apparently “fed” by that enlarged artery. Furthermore, pulmonary artery aneurysms do not connect directly to dilated pulmonary veins.
At this point, which of the following represents the correct diagnosis for this patient? (Click on the correct answer to be directed to the eighth of ten pages)