Extensive Paneth cell metaplasia in an ovarian Krukenberg tumor: report of an unusual case and literature review.

Paneth cells are classified as secretory cells which are normally found in the cecum and ascending colon. Their presence in other parts of the gastrointestinal tract is regarded as abnormal and indicates metaplasia. Paneth cells may also be rarely found in gastrointestinal, biliary and prostatic tumors.