Granulomatosis of WG

In addition to the right-sided consolidation, our patient had a nodule in the left lower lobe. Both probably had similar histologic findings.

The gross appearance of a nodule of WG is seen here in a specimen from another patient. This nodule has a somewhat irregular outline, but no evidence of necrosis. Bronchovascular structures have not been destroyed, and resolution is possible. The surrounding lung is dark red from alveolar hemorrhage.

The granulomatosis of WG produces diffuse consolidation composed of histiocytes, multinucleated giant cells, and chronic inflammatory cells, including variable numbers of PMNs and eosinophils. Note the non-encapsulated, irregular margin next to adjacent lung and the scattered giant cells.

The giant cells and histiocytes do not occur in discrete, rounded nodules as in sarcoidosis. Most of the giant cells here are of Langhans' type with a peripheral ring of nuclei, but foreign body type giant cells with nuclei scattered throughout the cytoplasm are also common in WG.

This discrete granuloma from a patient with sarcoidosis shows a circumscribed, rounded nodule of epithelioid cells, multinucleated giant cells, and lymphocytes. The surrounding alveolar parenchyma is fairly intact.

The word "granulomatous" refers to both diffuse and discrete types of inflammation. Granulomatosis refers to the diffuse, chronic inflammation with giant cells seen in WG, but it may also occur in other situations; for example, in infectious and aspiration pneumonias.

Clinical summary Necrosis Discussion

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