20
Diagnosis
Figure 4. (A–C) Poorly Formed Granulomas Characteristic
of Hypersensitivity Pneumonitis (HP) Contrasted
with (D and E) Well-formed Granulomas More
Typical of Sarcoidosis.
(A) High-magnification photomicrograph illustrating isolated multinucleated
giant cells in a surgical lung biopsy specimen from a patient with nonfibrotic HP.
Magnification, 400×. (B) Another photomicrograph illustrating giant cells in a patient
with HP. ese giant cells are distinguished by cytoplasmic cholesterol-like cles, a
nonspecific but common finding. Magnification, 400×. (C) In this high-magnification
photomicrograph of a surgical lung biopsy specimen, the giant cells are largely obscured
by cytoplasmic Schaumann bodies (arrow), another nonspecific but characteristic feature
of the granulomatous response in HP. Magnification, 400×. (D) Low-magnification
photomicrograph of surgical lung biopsy specimen from a patient with sarcoidosis
showing characteristic "lymphangitic" distribution, in which the granulomas are limited
to the interstitium and involve visceral pleura (asterisk), interlobular septa (arrow), and
bronchovascular bundles. Magnification, 20×. (E) High-magnification photomicrograph
showing a well-formed non-necrotizing granuloma in a surgical lung biopsy specimen
from a patient with sarcoidosis. e well-circumscribed, tight cluster of epithelioid
cells (macrophages) is affiliated with a characteristic pattern of circumferential lamellar
fibrosis. Magnification, 400×. Hematoxylin and eosin staining was used.
