pT3 colorectal adenocarcinoma
Friday 5 July 2013
Peritoneal involvement is an important adverse prognostic factor in colorectal cancer (CRC) and determines a shift in the pathologic tumor node metastasis stage.
Because peritoneal involvement is difficult to identify, use of special stains highlighting the peritoneal elastic lamina and mesothelial surface has been proposed.
The use of a single elastic stain is a useful and inexpensive method to demonstrate peritoneal involvement by tumor and should be considered for routine use in all pT3N0 CRCs. (23774172)
Reliable ancillary techniques for detecting serosal penetration by the tumor and accurate criteria for stage assessment are needed.
Authiors evaluated the utility of cytologic preparations in determining tumor stage by comparing results of serosal scrape cytology with histologic stage assessment of 120 colon cancer resection specimens.
They correlated their findings with the presence and type of inflammatory changes near the serosa to determine which, if any, are reliable indicators of peritoneal penetration.
Cytologic smears from all pT1 and pT2 tumors were negative for carcinoma. 19% of pT3 tumors showed cancer in cytologic smears, all of which were deeply invasive. In fact, 46% of pT3 cancers present ≤1 mm from a serosal tissue reaction were associated with cancer in cytologic preparations from the serosa, which was comparable to pT4a tumors (55%).
They conclude that cytologic smears improve detection of peritoneal penetration among pT3 tumors compared with histology alone.
Tumors close (≤1 mm) to a fibroinflammatory tissue reaction on the serosa are likely associated with peritoneal involvement by cancer.
Peritumoral abscesses that communicate with the serosa and hemorrhage or fibrin on the serosa also predict cancer involvement of the peritoneum.
The presence of these findings among deeply invasive cancers should prompt their classification as pT4a lesions.
Histologic Features and Cytologic Techniques That Aid Pathologic Stage Assessment of Colonic Adenocarcinoma. Panarelli NC, Schreiner AM, Brandt SM, Shepherd NA, Yantiss RK. Am J Surg Pathol. 2013 Jun 14. PMID: 23774176
Retrospective Evaluation of Elastic Stain in the Assessment of Serosal Invasion of pT3N0 Colorectal Cancers. Liang WY, Zhang WJ, Hsu CY, Arnason T, Berger D, Hawkins AT, Sylla P, Lauwers GY. Am J Surg Pathol. 2013 Jun 14. PMID: 23774172