Welcome back Readers to the last case in 2009! I think it is very fitting that this is Case 99, and that Case 100 will be the first case of 2010.
This case is a colon biopsy that contained an unexpected object:
(CLICK ON IMAGES TO ENLARGE)
For the non-pathologists, note that what we're seeing is a worm cut in cross-section. Use the internal structures to help you identify it. Another hint: notice that the worm portion shown is external to the intestinal mucosa.