Fig. 3

Mantle cell lymphoma arising from Warthin tumor stroma. a Histologic sections of the parotid gland demonstrate a well circumscribed lesion with a thin fibrous capsule that is sharply delineated from the adjacent uninvolved salivary gland parenchyma, with an expanded lymphoid stroma showing rare secondary follicular structures. b Higher magnification demonstrates the characteristic dual layered oncocytic cells of Warthin tumor. c The stromal lymphocytes are small to medium in size, with higher magnification (d) demonstrating clumped to vesicular chromatin patterns, irregular nuclear contours, inconspicuous to small distinct nucleoli, and scant clear cytoplasm. Hemotoxylin-eosin stain, original magnification 20× (a) 200× (b), 400× (c), and 1000× (d)