Peritumoral tissue reaction at transrectal US as a possible cause of overstaging in rectal cancer: histopathologic correlation.
OBJECTIVE
To assess if peritumoral tissue reaction (PTR) can be differentiated from tumor with transrectal ultrasound (TRUS) to avert overstaging.


METHODS
Preoperative TRUS results in 40 consecutive patients with biopsy-proved rectal cancer were compared with histopathologic reports on the specimens (study 1). To test the hypothesis that areas more anechoic than the tumor were deemed responsible for incorrect staging in study 1, a prospective study was undertaken in another 40 consecutive patients (study 2). The thickest part of PTR was measured, and results were compared with the histopathologic findings.


RESULTS
In study 1, 28 (70%) of 40 rectal cancers were staged correctly with TRUS. PTR was responsible for the misinterpretation in six of seven overstaged cases. In study 2, 38 (95%) of 40 cancers were staged correctly, and the presence or absence of PTR was described in 39 cases (98%). A statistically significant positive correlation was noted between histopathologic classification of PTR and its thickness measured with TRUS (P = .0001).


CONCLUSIONS
Because of its more anechoic appearance, PTR may be differentiated from the tumor by means of TRUS. This may lead to a statistically significantly higher accuracy of TRUS in the staging of rectal cancer due to the avoidance of overstaging.
Maier
A G
AG
Department of Radiology, University of Vienna Medical School, Austria.
Barton
P P
PP
Neuhold
N R
NR
Herbst
F
F
Teleky
B K
BK
Lechner
G L
GL
D000273:Adipose Tissue / Q000000981:diagnostic imaging / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000000981:diagnostic imaging / Q000473:pathology; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011300:Preoperative Care; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D012007:Rectum / Q000000981:diagnostic imaging*; D012704:Serous Membrane / Q000000981:diagnostic imaging / Q000473:pathology; D012812:Sigmoidoscopy; D014463:Ultrasonography