Use of an elastic stain to show venous invasion in colorectal carcinoma: a simple technique for detection of an important prognostic factor

BACKGROUND

Venous invasion (VI) is an important prognostic factor in colorectal cancer; it is positively associated with visceral metastases and may affect the decision to treat with adjuvant therapy.

AIMS

To evaluate whether an elastic tissue (Movat) stain facilitates identification of VI, the number of Movat-stained blocks needed to detect VI, and whether VI identified with a Movat stain is prognostically equivalent to VI identified on H&E-stained slides.

METHODS

H&E-stained sections from colorectal carcinomas from the year 2000 (n = 92) were examined for VI and compared to Movat-stained slides. Clinical charts were reviewed to compare rates of metastases in VI-positive versus VI-negative patients.

RESULTS

With the Movat stain, VI was identified in 44% of cases previously categorised as negative (p<0.001) on review of H&E slides alone. One Movat-stained section was often sufficient to identify VI, with a statistically significant benefit to performing multiple stains if necessary. In H&E sections, two clues helped identify VI: the "unaccompanied artery" sign, where large arteries were seen without an accompanying vein; and the "protruding tongue" sign, where smooth tongues of tumour extended into pericolic/rectal fat. Metastases were present in 61% of cases positive for VI compared to 35% in VI-negative cases (p = 0.03). 45% of cases positive for intramural VI only developed metastases (p = 0.39), while 65% of cases positive for extramural VI only developed metastases (p = 0.03).

CONCLUSIONS

Pathologists should look for morphological clues of VI in H&E stained sections; when VI is not apparent, an elastic tissue stain on all tumour blocks significantly improves identification of VI. Morphological clues include the "unaccompanied artery" and "protruding tongue" signs.

Plastic bread-bag clips in the gastrointestinal tract: report of 5 cases and review of the literature

Plastic bread-bag clips have been identified as a cause of local perforation or obstruction at many sites in the gastrointestinal tract. This study is the largest case series yet reported, consisting of 3 cases presenting as small-bowel perforation, 1 case in which the clip was found incidentally in the small bowel at laparotomy during vascular surgery and 1 case in which the clip was found incidentally in the small bowel at autopsy. In all cases there was no radiographic evidence to suggest a foreign body in the gastrointestinal tract. People older than 60 years of age who have either partial or full dentures seem to be particularly at risk for the accidental ingestion of these devices. If accidentally ingested, plastic bread-bag clips represent a significant health hazard. As the population ages, small-bowel perforation secondary to ingestion of such clips may occur with increasing frequency. The authors recommend elimination or redesign of the clips, to prevent their being swallowed and becoming impacted in the small bowel or to allow them to be identified in the gastrointestinal tract by conventional radiography.