Figure 4.

Histopathology of the second surgical specimen. A, A nodular lesion well circumscribed by interlobular septa. Lymphoid hyperplasia with germinal centers and exudative changes (left, hematoxylin and eosin staining; right, Elastica-van Gieson staining). B, Proliferation of collagen fibers and destruction of alveolar elastic fibers (left, hematoxylin and eosin staining; right, Elastica-van Gieson staining). C, Infiltrating lymphocytes and plasma cells without atypia. D, Lymphocytic infiltration of vascular walls (left, hematoxylin and eosin staining; right, Elastica-van Gieson staining).