Histologic Changes

This is the nodule, 1 x 0.6 x 0.6 cm, that was removed in 5/91. It is a homogeneous, pink mass that replaces lung parenchyma. Margins are smooth or slightly lobulated.


At higher magnification, there are a few inflammatory cells embedded in the edge of the nodule, and the pink material surrounds and narrows three vessels at the bottom (arrows).

The upper arrow indicates the cell type that is most frequent in this lesion. What is it?

The lower arrow indicates another cell type that is frequent in these lesions. What is it?

What special stain is needed for diagnosis?

What is the diagnosis of the lesion? Answers

Evaluation of asbestos exposure: Sections of the surrounding lung parenchyma were stained for iron and scanned serially at a magnification of 100 X for ferruginous bodies (fb). Thirty-one fb were found in an area of 4.81 cm2 giving 6.4 fb/cm2. Sections were also stained with the elastic van Gieson stain to detect fibrosis. A mild degree of patchy peribronchiolar and interstitial fibrosis was found in addition to a mild alveolitis with increased interstitial chronic inflammation and alveolar macrophages. In a patient with a history of work in construction, it is highly likely that the cores of the ferruginous bodies are asbestos. The asbestos bodies and fibrosis constitute asbestosis.

Diagnosis: Asbestosis, mild

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The upper arrow indicates a plasma cell with a round to ovoid eccentric nucleus and plentiful cytoplasm. Some lymphocytes with little visible cytoplasm are also present.

The lower arrow indicates a multinucleated giant cell.

Special stain: A Congo red stain was positive and showed green birefringence with polarized light.


Diagnosis: Nodular amyloidosis (amyloidoma)

Multinucleated giant cells are a frequent occurrence around amyloid deposits. Sometimes they are so frequent that they suggest a granulomatous inflammatory response.

Rarely, transbronchial or needle biopsy of amyloid is associated with bleeding, probably because vessels with amyloid in their walls cannot contract properly.

Clinical summaryImage 2

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