T3 anorectal adenocarcinoma

Case contributed by Dr Jan Frank Gerstenmaier


This patient presents with an ulcerating anorectal mass and bleeding.

Patient Data

Age: 70
Gender: Male

MRI Pelvis (staging)

MR Rectal Cancer Staging

Multiplanar noncontrast small field of view MR imaging of the pelvis has been obtained. The anorectal rectal tumor extends between the lower rectum  and the anal verge.The superior border lies below the peritoneal reflection. It measures 10.5 cm inn length, and extends from 9 to 2 o'clock (clockwise). The tumor has two components - lower rectal and lower anal. The impression is that the two components are contiguous by a thin stalk along the anal canal where tumor is based at the 12 o'clock position superiorly and at the 10 o clock position in the mid-lower anal canal.

Tumor invades the muscularis propria and extends 5 mm into the mesorectal fat at 10-1 o clock where it abuts Denonvillier's fascia. The colorectal resection margin (CRM) is at risk here. There is no evidence of prostate invasion however. In the anal canal there is evidence of sphincter involvement but no T4 disease is seen. There no convincing evidence of extramural venous invasion. The peritoneal reflection is not involved. There is one suspicious mesorectal lymph nodes. There are no bone mets evident. There is no extension into the presacral fat.

Conclusion: This is an advancedT3 N1 MX anorectal cancer CRM is at risk at 10 - 1 o clock where T3 disease abuts Denonvillier's fascia.


CT chest, abdomen and pelvis

Oral and intravenous contrast enhanced examination.

Mural thickening at the anorectal junction is compatible with the stated site of primary tumor. No enlargement of thoracic, abdominal or pelvic lymph nodes. No pleural effusion. Nonspecific 4 mm nodule in the right lower lobe (image 42 series 6). Punctate dense (almost certainly benign) micronodule in the right posterior lung base. No other pulmonary nodule or mass. Uncomplicated sigmoid diverticular disease. Right renal simple cortical cyst. Other abdominal viscera are within expected limits. In particular, there is no evidence of focal liver lesion. Small non-specific sclerotic focus in the left fifth lateral rib. Note made of left total hip replacement.

Conclusion:No definite evidence of metastatic disease. A 4 mm right lung nodule and a small sclerotic focus in the left fifth lateral rib are non-specific.

Case Discussion

On sagittal imaging there is impression of two separate tumor masses, rectal and anal. On axial images through the anal canal, a thin stalk of connecting tumor is visible between the two dominant tumor masses. On imaging this is a T3 N1 M0 tumor, i.e. stage IIIB.

The plan is abdominoperitoneal resection following neo-adiuvant chemoradiotherapy.

Histology to follow.

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Case information

rID: 30913
Published: 11th Sep 2014
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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