Case Author(s): M. Roarke , 9/1/95 . Rating: #D3, #Q4
Diagnosis: Tubulovillous adenoma of the colon hepatic flexure.
Brief history:
This patient had an annular
constricting rectal Dukešs stage C carcinoma resected
in September 1994. Before this resection, the patient
had received a course of radiation therapy.
Subsequent to the resection, the patient received
chemotherapy. On a follow-up colonoscopy in April
1995, a sessile mass was noted in the ascending colon.
This mass was not noted prior to the operation since
colonoscopy could not be performed due to the marked
stricturing the rectal carcinoma. Biopsy in April 1995
demonstrated benign histology. The patient had a
repeat colonoscopy on 7-11-95, which again
demonstrated the sessile mass in the region of the
ascending colon/hepatic flexure. In light of the
previous history of rectal carcinoma, a PET study was
requested to evaluate for metastatic disease prior to
resection of the hepatic flexure lesion. Biopsy of the
hepatic flexure lesion on 7-11-95 again demonstrated
a benign histology. Patient with a history of
annular constricting rectal Dukešs stage C carcinoma
resected in September 1994.
Images:
Images from whole body F-18 FDG PET study.
View main image(pt) in a separate image viewer
Full history/Diagnosis is available below
Diagnosis: Tubulovillous adenoma of the colon hepatic flexure.
Full history:
This patient had an annular
constricting rectal Dukešs stage C carcinoma resected
in September 1994. Before this resection, the patient
had received a course of radiation therapy.
Subsequent to the resection, the patient received
chemotherapy. On a follow-up colonoscopy in April
1995, a sessile mass was noted in the ascending colon.
This mass was not noted prior to the operation since
colonoscopy could not be performed due to the marked
stricturing the rectal carcinoma. Biopsy in April 1995
demonstrated benign histology. The patient had a
repeat colonoscopy on 7-11-95, which again
demonstrated the sessile mass in the region of the
ascending colon/hepatic flexure. In light of the
previous history of rectal carcinoma, a PET study was
requested to evaluate for metastatic disease prior to
resection of the hepatic flexure lesion. Biopsy of the
hepatic flexure lesion on 7-11-95 again demonstrated
a benign histology.
Findings:
A single focus of moderately
increased activity was found in the area of the
previously described sessile mass in the ascending
colon hepatic flexure suspicious for malignancy. At
surgery, this lesion proved to be a tubulovillous
adenoma with a single area of atypia.
Discussion:
As of this writing, PET imaging
may not be sufficiently specific in differentiating
between malignant and some benign neoplasms of the
colon.
Followup:
Resection of the sessile mass in the
region of the hepatic flexure/ascending colon revealed
tubulovillous adenoma without evidence of
malignancy.
Major teaching point(s):
Although FDG-PET is very
useful in differentiating between recurrent colorectal
cancer and fibrosis, it may not be specific in
distinguishing malignant neoplasms of the colon from
some of the benign lesions with a high metabolic rate.
ACR Codes and Keywords:
References and General Discussion of PET Tumor Imaging Studies (Anatomic field:Gasterointestinal System, Category:Neoplasm, Neoplastic-like condition)
Search for similar cases.
Edit this case
Add comments about this case
Return to the Teaching File home page.
Case number: pt003
Copyright by Wash U MO