Peritoneal carcinomatosis - colorectal carcinoma

Case contributed by Dr Michael P Hartung


Mid abdominal pain.

Patient Data

Age: 50 years
Gender: Male

Medium amount of abdominal ascites.

Thickening and nodularity of the omentum forming an omental cake. Few areas of subtle nodularity in the peritoneum, for example right paracolic gutter. Thickening and irregularity of the distal descending/proximal sigmoid colon, without obstruction. Several low-attenuation hepatic lesions.

Small right and trace left pleural effusions. 

Near obstructing colonic mass at 40 cm
2 cm polyp at 20 cm

Incomplete colonoscopy with biopsy of the mass.
Sigmoid polyp

Patient comes to us after presenting the emergency room earlier this week with abdominal pain and was diagnosed with presumed carcinomatosis ascites liver metastases and a stricturing lesion of the proximal sigmoid colon by CT. He is without a sense of obstipation or constipation. He did tolerate his bowel prep.


Digital exam was unremarkable. I used the adult endoscope to get her approximately 40 cm. With a water lavage technique I could identify a concentric lumen about inflamed mucinous circumferential abnormal tissue. I attempted to use a pediatric scope. I could not cross this area.

I took several cold biopsies of the area. Approximately 35 cm there is a quarter sized area that appeared hypervascular and I elected not to biopsy this. At 20 cm there is a pedunculated polyp that was irregular and approximately 2 cm that was removed by snare cautery.


Specimen A - Received in formalin labeled sigmoid 40 cm are four 0.2 cm tan mucosal
fragments which are entirely submitted in cassette A.
Specimen B - Received in formalin labeled sigmoid 20 cm is an irregular 1.5 x 1.0 x 1.0
cm tan/red polypoid mucosal fragment which is bisected and entirely submitted in
cassette B.

40 cm - Irregular glands within desmoplastic stroma, consistent with invasive

Colon, sigmoid, 40 cm, biopsy - Moderately differentiated adenocarcinoma.
Colon, sigmoid, 20 cm, biopsy - Tubular adenoma.

Case Discussion

Fairly typical case of peritoneal carcinomatosis from colon cancer, evidenced by ascites, peritoneal nodularity, omental thickening, and hepatic metastases. In the absence of a known primary tumor, ultrasound-guided biopsy of the omentum can be safely performed to obtain tissue diagnosis.

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Case information

rID: 60828
Published: 9th Jun 2018
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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