Lieberkuhn crypts

Crypt abscess Neutrophilic infiltration of the intestinal glands (crypts of Lieberkuhn) a characteristic finding in patients with ulcerative colitis. 

Fig. 9.5. Scolex of Echinococcus granulosus in the duodenum of the dog tissue fixed rapidly with hot Zenker s fluid. The rostellum is extended into a crypt of Lieberkuhn with the hooks lightly penetrating the epithelium, some cells of which have become flattened and destroyed. The adult worm must therefore be considered to be both a tissue and an intestinal parasite.

The primary lesion of ulcerative colitis occurs in the crypts of the mucosa (crypts of Lieberkuhn) in the form of a crypt abscess. Here, frank necrosis of the epithelium occurs it is usually visible only with microscopy, but may be seen grossly when coalescence of ulcers occurs. Extension and coalescence ulcers may surround areas of uninvolved mucosa. These islands of mucosa are called pseudopolyps. 

In 1930, F. Feyrter (top left) of Gdansk proposed the existence of a diffuse system of neuroendocrine cells in the gastrointestinal tract (center). Thereafter, P. Masson (1880-1959) (bottom right) described in detail the characteristics of the cells that formed the basis of the diffuse neuroendocrine system (back-ground). In addition, Masson proposed that the enterochromaffin cells in the crypts of Lieberkuhn (which had been identified by N. Kulchitsky in 1897) were the progenitors of neuroendocrine tumors of the gut (carcinoids). 

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