Case 6

Section 1

Image 1

What is the distribution of the abnormal densities?

a) Bronchovascular
b) Interlobular septal
c) Pleural
d) Centrilobular




Section 2

Here, broad areas of thickened bronchovascular interstitium have become confluent with thickened interlobular septa, which together have caused disortion of the architecture.

Image 1

Find an example in the right lung of combined bronchovascular and interlobular septal thickening with distortion of the architecture.

Find an example in the left lung of thickened bronchovascular interstitium.

Find a centrilobular nodule, representing thickening of the terminal bronchiolovascular interstitium, in the left lung.

bvilsbvbundleclnoduleFind other examples of tenting of the pleura, which indicates architectural distortion.

Section 3

Gross Appearance

This slice of lung shows vessels, bronchi, and enlarged lymph nodes.

Find lymph nodes.

Find the main pulmonary artery. The adjacent thinner-walled vessel is the vein.

Find and outline a longitudinally-cut, segmental bronchus with thickened bronchovascular interstitium that narrows the lumen. This bronchovascular interstitial involvement corresponds to that seen in the HRCT image above. Architectural distortion may result.

Find other airways cut in cross-section that are also narrowed.


Section 4

Histologic Appearance

This picture shows thickening of the interstitium.

Find an airway and name its type.

Find the accompanying pulmonary artery branch.

Find and identify 5 rounded, interstitial, cellular structures.

Find and identify the composition of the pink matrix.


Differential diagnosis of nodular bronchovascular and interlobular septal thickening on HRCT: Sarcoidosis, lymphangitic tumor, lymphoma, Kaposi's sarcoma

Histologic differential diagnosis: Infectious granulomatous disease (tuberculous or fungal), hypersensitivity pneumonia (fibrosis is present only in late stages of the disease), and reaction to tumor or drug should be considered.

Diagnosis: Chronic sarcoidosis

Summary of diagnostic features of sarcoidosis on HRCT

Comment: The HRCT abnormalities were primarily in the upper portions of the lungs. Chronic sarcoidosis typically affects the upper lung zones in a bronchovascular, interlobular septal, and pleural distribution leading to architectural distortion due to fibrosis.

Compare this case to that of lymphangitic tumor (use the "back" button in the menu bar to return), which also has bronchovascular, interlobular septal, and pleural thickening, but lacks architectural distortion.

See Case Study 33 for other examples of sarcoidosis. Note especially the page on chronic sarcoidosis.



Table of Contents

























Mainly bronchovascular and interlobular septal with a few foci of pleural and centrilobular densities.























Bronchovascular and interlobular septal thickening with distortion of the mediastinal pleura in two locations


























Bronchovascular interstitial thickening that is in continuity with a thickened interlobular septum laterally



























Centrilobular nodule representing thickening of terminal bronchiolovascular interstitium





















Enlarged lymph nodes






















Pulmonary artery. The thinner-walled vessel to the left is the pulmonary vein





















Segmental bronchus. Note that the thickened interstitium occurs on both sides of the white bronchial cartilages.























Bronchiole (airway has no cartilage)






















Branch of pulmonary artery






















The rounded, interstitial, cellular structures are single or clustered, non-necrotizing granulomas.






















Collagenous matrix typically seen in chronic disease