Detection of venous invasion in surgical specimens of colorectal carcinoma: the efficacy of various types of tissue blocks: Table 1

Abstract

Background: Venous invasion (VI) is an important prognosis predictor after colorectal carcinoma (CRC) resection, enabling more accurate staging and influencing postoperative management. Aims: To assess/compare various tissue block types (perpendicular, tangential, across mesentery (AM), from major vessels or lymph nodes (LNs)) for VI detection in CRC. Methods: Fifty two CRCs (51 colectomies, one polypectomy) were studied. Tumours were measured, surface area calculated, and colorectum and bowel wall sites recorded. Weigert's staining for elastin facilitated VI detection. VI sites, type, and amount were recorded. Ratios of relative yield of tissue block types to their frequency were calculated. Results: Average numbers of tissue blocks/colectomy specimen were: perpendicular, 10.2; tangential, 9.1; AM, 3.3; from major vessels, 2.1. Average number of LNs examined was 16.47. VI was detected in 22 tumours. Overall, VI was detected in 16 perpendicular, seven tangential, five AM, and two LN blocks. VI was detected in eight, two, one, and three tumours in perpendicular, tangential, LN, and AM blocks alone, respectively. In seven tumours, VI was identified in multiple tissue block types. The average number of blocks obtained was 39.7, 42.1, and 38 from all tumours, VI positive, and VI negative tumours, respectively (p = 0.0497). Efficacy to detect VI was 2.151, 2.088, 1.092, 0.172, and 0 for AM, perpendicular, tangential, LN, and mesenteric vessel blocks, respectively. Conclusions: VI was identified most frequently and in eight cases only in perpendicular blocks. However, extramural VI was detected in six tumours only in blocks cut tangentially, AM, or from harvested LNs. Hence, all these types of blocks should be submitted routinely and scanned for VI.

Vascular Invasion is Underrecognized in Colorectal Cancer Using Conventional Hematoxylin and Eosin Staining

“…This situation is in some ways analogous to the identification of Bmicrometastases^within lymph nodes draining primary tumors in that the clinical significance of this phenomenon is unclear and may be variable between tumor types-being more significant in malignant melanoma than most carcinomas, for example. 15 This is reflected in the current TNM staging guidelines, which indicate that collections of tumor cells < 0.2 cm across within lymph nodes should be termed Bmicrometastases.^1 6 Within colorectal cancer, studies combining detailed characterization of VI with long-term clinical follow-up will be required to determine the true clinical significance of VI when identified using methods additional to H&E alone. Patients with Dukes C (pTanyN1/2) CRC are now considered for postoperative chemotherapy, whereas this additional treatment is considered for patients with Dukes B * VI was recorded as present if identified using one or more of the four demonstration methods.…”

“…The utility of histochemical staining for elastic fibers has been previously demonstrated in CRC. 5,6 Immunohistochemical highlighting of vascular spaces in CRC has previously been performed using factor VIII related antigen and Ulex europeus lectin (both uncommonly used in routine practice today) 8-10 but use of the more modern endothelial markers, such as CD31 and CD34, has been restricted to studies of microvessel density in CRC. 11 Therefore, to our knowledge, our study is the first to use CD31 and CD34 immunohistochemistry to study VI in CRC and to compare these methods to routine hematoxylin staining and elastic fiber immunohistochemistry.…”

“…However, previous studies using histochemical staining for elastic fibers have suggested that this might result in significant underrecognition of VI compared with enhanced methods in which the vessel walls are highlighted. 5,6 This study was designed to test the hypothesis that the use of connective tissue staining and immunohistochemical staining to highlight blood and lymphatic vessel walls significantly increases the proportion of cases of colorectal cancer in which extramural and intramural VI is identified.…”

Vascular invasion detected by orcein staining and its significance in different tumours, with emphasis on colorectal cancer

“…To minimize the false negative rate, they suggested increasing the number of blocks and slides, using elastic stains and cutting tangential blocks from the perimeter of the tumour, across the mesentery, and from mesenteric vessels. Their results indicate that there is a direct relationship between VI incidence and tumour stage, while inverse relationship was found between VI incidence and tumour differentiation, and the greater mean number of blocks was examined, the higher rates of VI were detected [31]. According to the calculation of Talbot el al., 3.9% of cases with extramural VI would be missed if 5 blocks were taken, while 41.3% would be missed if only 2 blocks were processed [34].…”

“…Sternberg applied similar system with partially different designations [31]. Most of the studies have found invasion type insignificant [26].…”