Fig. 4.19 CT of same patient showing calcification in RML; note the shape resembles popcorn, compatible with hamartoma

Pattern: Mass (nodule).

Differential Diagnosis: This finding is nearly characteristic of benign neoplasm, specifically hamartoma. Granuloma is less of a consideration since the nodule in this case is irregularly calcified. Of the general mass differential, inflammation, congenital, and malignancy are less likely.

Congenital Abnormality

Pulmonary Arteriovenous Malformations

Certain congenital conditions such as Pulmonary Arteriovenous Malformations can resemble mass and therefore satisfy the mass category.

Case 4.7

An example is shown below with several mass-like structures seen on the initial CXR.

Findings: Multiple focal opacities seen bilaterally, sparing the apicies. Pattern: Mass, multiple.

Differential Diagnosis

•Malignancy

•Granulomatous

•Inflammation, other

•Benign neoplasm

•Congenital