Accurate specimen preparation and examination is mandatory to detect lymph nodes and avoid understaging in colorectal cancer

Abstract

Lymph node involvement in colorectal cancer, one of the most important prognostic factors, can be sometimes underestimated. In this study the authors report the results of two different techniques of specimen preparation and examination. In 240 patients (Group I), histologic examination was performed using a conventional procedure. In Group II (60 cases) the resected bowel and its mesentery were separately stretched, pinned on to a cork board, and fixed. The mesentery was divided according to node location (intermediate and principal) and evaluated by sight and palpation to identify lymph nodes. The bowel segment was divided from 5 cm proximally to 5 cm distally to the tumor every 10 mm in serial 3 mm slices. Three and 10 mm slices were then carefully examined by sight and palpation. Isolated lymph nodes embedded in groups (10-12 per paraffin block) were stained and investigated for neoplastic involvement. The specimen examination procedure used in Group II resulted in identification of a higher number of lymph nodes (mean = 41.1) and nodal metastases (mean = 10) compared to the standard technique used in Group I (mean = 11.3 and 2.4, respectively--P < .05). The percentage of N+ cases also was increased in Group II (48.3%) when compared to that in Group I (30.4%; P < .05). The new technique is simple, inexpensive, and efficacious for the detection of lymphatic metastases in colorectal cancer.

Techniques to increase lymph node harvest from gastrointestinal cancer specimens: a systematic review and meta‐analysis

“…Fat stretching and MB staining combined with fat clearing were also shown to increase lymph node yield significantly when compared to MND 27,39 …”

Is there a minimum number of lymph nodes that should be histologically assessed for a reliable nodal staging of T3N0M0 colorectal carcinomas?

“…There are large differences between different studies as concerns the number of lymph nodes examined; the difference may even be fourfold [18]. The major influencing factors here are probably related to the extent of surgery and the diligence of the pathology staff in the search for lymph nodes.…”

Reliability and Effectiveness of GEWF Solution in the Identification of Lymph Nodes in Specimens of Colorectal Carcinoma

“…[7][8][9][10][11][12] Furthermore, handling with other adjunctive solutions, including GEWF (glacial acetic acid, ethanol, distilled water, and formaldehyde) solution, has also been proposed to improve lymph node harvest. [13][14][15][16][17][18] Since its introduction by Newell et al, 13 the efficiency of GEWF solution in retrieval of lymph nodes from the CRC resections has been a subject of debate in the literature. 7,8,[10][11][12][13] It is therefore interesting to further evaluate the reliability and effectiveness of GEWF solution in our own cases, because there was a relatively high proportion of conventionally fixed CRC resections having 12 or more yielded lymph nodes in our institution (86.9% in 2011).…”