Squamous cell carcinoma of the colon and rectum, originating proximal
to the transitional zone, is a rare complication of idiopathic inflamm
atory bowel disease (IIBD). To date there are only 15 single case repo
rts of such an occurrence. This carcinoma develops more commonly in fe
males and in patients with pancolonic disease of more than 8 years' du
ration. The rectum is affected in two thirds of the cases. Squamous ce
ll changes, in the vicinity of the primary adenocarcinoma, are present
in 27% of cases. The carcinoma is in a pathologically advanced stage
in one third of the cases. Colectomy is the main therapeutic modality.
Survival following surgical resection ranged from 7 months to 21 year
s. We present an additional case of rectal squamous cell carcinoma (SC
C) complicating chronic ulcerative colitis in a 33-year-old woman who
had the disease for 15 years. Multiple biopsies of a gross lesion loca
ted 5 cm above the dendate line were consistent with invasive basaloid
cell carcinoma. The patient received 5-FU, mitomycin C, and radiother
apy prior to a proctocolectomy and ileostomy. The only histopathologic
finding at pathologic review of the surgical specimen was severe squa
mous dysplasia. (C) 1995 Wiley-Liss, Inc.