Palatine tonsil ('lymphoepithelial tissues', 'gut-associated lymphatic tissue' or GALT) (human)

Stain: Azan. A low magnification in A shows the thick blue connective septum (1) with a secondary lymphatic nodule (2). (3) is a cross-section of a crypt filled with detached squamous epithelium (3a) mixed up with keratinized material (red) and a huge amount of lymphocytes (3b). A higher magnification in (B) reveals diapedesis of groups of lymphocytes (4) localized between flattened interconnected squamous cells (3c), deep-stained red structures represent dead keratinized cells. At (5) accumulated apoptotic cells.