Paneth cells have been reported in colorectal adenomas and adenocarcinomas; 
however, the frequency of colonic Paneth cell-containing adenomas is unknown as 
are their clinicopathologic features. A total of 152 consecutive colorectal 
adenomas from 103 patients (57 males and 46 females) were reviewed. The 
frequency of Paneth cells in this cohort of adenomas was determined and 
correlated with patient demographics. Twenty-six adenomas (17.1%) from 22 
(21.4%) patients harbored Paneth cells, which were not limited to the base of 
the crypts but aberrantly located throughout the crypts. Patient age, adenoma 
size, villous features, and grade of dysplasia were not different between these 
2 groups. Not surprisingly, Paneth cell-containing adenomas were more likely to 
occur in the proximal colon (84.6% vs. 55.6%; P=0.006). There was a strong 
association between male sex and Paneth cell-containing adenomas, as 23 of 26 
(88.5%) of these adenomas occurred in male individuals compared with 71 of 126 
(56.3%) non-Paneth cell-containing adenomas (P=0.002). Upon review of an 
additional 460 adenomas from 200 patients with varying numbers of adenomas (68 
with 1 adenoma, 68 with 2 adenomas, and 64 with 3 or more adenomas), the risk of 
harboring synchronous adenomas was associated with villous morphology, proximal 
location, and the presence of a Paneth cell-containing adenoma. Thus, the 
presence of a Paneth cell-containing adenoma may be a marker for increased risk 
of developing colorectal neoplasia.