Bone formation in a rectal inflammatory polyp

Table 1 Summary of reported cases of osseous metaplasia in benign colorectal polyps

Case	Author	Year	Age	Gender	Size (mm)	Location	Histology	Inflammation	Mucin deposition	Ref.
1	Sperling	1981	25	M	10	Rectum	Inflammatory polyp	+	+	[3]
2	Castelli	1992	22	F	10	Rectum	Inflammatory polyp	+	-	[4]
3	Groisman	1994	67	M	18	Rectum	Tubulovillous adenoma	-	-	[5]
4	Groisman	1994	3	F	20	Rectum	Juvenile polyp	+	+	[5]
5	Cavazza	1996	NI	NI	NI	NI	Tubulovillous adenoma	NI	NI	[6]
6	McPherson	1999	73	M	20	Cecum	Tubulovillous adenoma	-	-	[7]
7	Rothstein	2000	NI	NI	25	Sigmoid colon	Tubular adenoma	-	-	[8]
8	AI-daraji	2005	85	F	15	Sigmoid colon	Tubular adenoma	-	-	[9]
9	White	2008	63	F	NI	Transverse colon	Tubular adenoma	+	-	[10]
10	Present case	2009	39	M	12	Rectum	Inflammatory polyp	+	-	Present case

NI: Indicates not informative.