Ex vivo sentinel node mapping in carcinoma of the colon and rectum

OBJECTIVE: Increasing evidence supports that the sentinel node (SN) is at greatest risk for harboring metastatic disease. This study describes a novel technique to identify the SN in colorectal carcinoma. METHODS: Within 30 minutes of resection, colorectal specimens were injected submucosally with isosulfan blue in four quadrants. Blue lymphatic channels were identified in the mesentery and followed to the blue-stained SN(s), which were then harvested. The specimen was fixed in formalin and subsequently analyzed in the usual fashion. Blue-stained nodes that were negative by hematoxylin and eosin staining were further analyzed by immunohistochemical staining. RESULTS: During a 6-month period, 26 patients with adenocarcinoma of the colon and rectum undergoing routine resection were studied. There were 18 men and 8 women ranging in age from 29 to 86 years (median 66). Blue-stained SNs were identified in 24 of 26 specimens. The mean number of SNs identified per patient was 2.8 +/- 1.6. Seventy-three SNs were identified from a total of 479 lymph nodes harvested. The mean number of nodes identified per patient was 18.4 +/-7. A total of 67 lymph nodes in 12 patients were identified by hematoxylin and eosin staining to have evidence of metastatic disease. Fourteen (20%) of these nodes in six patients were stained blue. However, with immunohistochemical staining, only one blue node did not have evidence of metastatic tumor in a lymphatic basin with tumor present. Four patients (29%) whose lymphatic basins were negative by hematoxylin and eosin staining were upstaged by immunohistochemical staining of the SN. CONCLUSIONS: Ex vivo mapping of the colon and rectum is technically feasible and may provide a useful approach to the ultrastaging of colorectal carcinoma.     

Laparoscopic lymphatic mapping and sentinel lymph node detection in colon cancer: technical aspects and preliminary results

Background The utility of lymph node mapping to improve staging in colon cancer is under evaluation. Laparoscopic colectomy for colon cancer has been validated in multicentric trials. This study assessed the feasibility of lymph node mapping in laparoscopic colectomy for colon cancer. Methods From March 2004 to December 2005, 22 patients were studied. Before resection, 2 to 3 ml of Patent Blue V dye was injected subserosally around the tumor. Colored lymph nodes were marked as sentinel nodes (SNs) with metal clips, and laparoscopic colectomy with lymphadenectomy was completed as normal. In SNs, multiple 4-μm slices at 50-μm intervals were stained with hematoxylin and eosin and examined. Anticytokeratin antibody immunostaining was applied in doubtful cases. Other lymph nodes were examined with multiple slices at 100- to 500-μm intervals by standard methods. Results The SN detection rate was 100%, although ex vivo lymph node mapping was necessary for an obese patient. Five patients (22.7%) were SN positive. There was one false-negative SN (16.7%). In two cases (9.1%) with aberrant lymphatic drainage, lymphadenectomy was extended. The SN reflected the status of the regional lymph nodes in 21 patients (95.4%). Accuracy was 95.4%, and negative predictive value was 94.1%. Conclusions Laparoscopic lymphatic mapping and SN removal is feasible in laparoscopic colectomy for colon cancer. Although the false-negative rate was high (16.7%), the overall results are promising and justify prospective studies to determine the real accuracy and false-negative rate for the technique. Presented at the annual meeting of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), April 26–29, 2006, Dallas, Texas, USA     

Intraoperative sentinel node detection improves nodal staging in invasive bladder cancer

PURPOSE: We evaluated intraoperative SN detection in patients with invasive bladder cancer during radical cystectomy in conjunction with extended lymphadenectomy. MATERIALS AND METHODS: A total of 75 patients with invasive bladder cancer underwent radical cystectomy with extended lymphadenectomy. SNs were identified by preoperative lymphoscintigraphy, intraoperative dynamic lymphoscintigraphy and blue dye detection. An isotope (70 MBq (99m)Tc-nanocolloid) and Patent Blue(R) blue dye were injected peritumorally via a cystoscope. Excised lymph nodes were examined ex vivo using a handheld gamma probe. Identified SNs were evaluated by extended serial sectioning, hematoxylin and eosin staining, and immunohistochemistry. RESULTS: At lymphadenectomy an average of 40 nodes (range 8 to 67) were removed. Of 75 patients 32 (43%) were lymph node positive, of whom 13 (41%) had all lymph node metastases located only outside of the obturator spaces. An SN was identified in 65 of 75 patients (87%). In 7 patients an SN was recognized when the nodal basins were assessed with the gamma probe after lymphadenectomy and cystectomy. Of the 32 lymph node positive cases 26 (81%) had a positive (metastatic) SN. Thus, the false-negative rate was 6 of 32 cases (19%). Five false-negative cases had macrometastases and/or perivesical metastases. In 9 patients (14%) the SN contained micrometastases (less than 2 mm), in 5 of whom the micrometastasis was the only metastatic deposit. CONCLUSIONS: SN detection is feasible in invasive bladder cancer, although the false- negative rate was 19% in this study. Extended serial sectioning and immunohistochemistry revealed micrometastases in SNs in 9 patients and radio guided surgery after the completion of lymphadenectomy identified SNs in an additional 7. We believe that the technique that we used in this study improved nodal staging in these 16 of 65 patients (25%).     

Use of sentinel node mapping for cancer of the colon: 'to map or not to map"

Sentinel lymph node (SLN) mapping has become a cornerstone of oncologic surgery because it is a proven method for identifying nodal disease in melanoma and breast cancer. In addition, it can ameliorate the surgical morbidity secondary to lymphadenectomy. However, experience with SLN mapping for carcinoma of the colon and other visceral malignancies is limited. This study represents an update to our initial pilot experience with SLN mapping for carcinoma of the colon. Consenting patients over the age of 18 diagnosed with adenocarcinoma of the colon were included in this study. At the time of operation, 1 to 2 mL of isosulfan blue was injected with a 25-gauge needle into the subserosa at 4 sites around the edge of the palpable tumor. The SLN was identified visually and excised followed by a standard lymphadenectomy and surgical resection. SLNs were evaluated by standard hematoxylin and eosin (H&E) evaluation as well as immunohistochemical (IHC) techniques for carcinoembryonic antigen and cytokeratin if the H&E was negative. Sixty-nine patients underwent SLN mapping. A SLN was identified in 93 per cent (64 of 69) of patients. Nodal metastases were identified in 38 per cent (26 of 69) of patients overall. In 5 patients, the only positive node identified was the SLN, 2 of which were positive by IHC criteria alone. Therefore, 3 per cent (2 of 69) of patients were upstaged by SLN mapping. This technique was 100 per cent specific while being 46 per cent sensitive. Fourteen patients had false-negative SLNs. Metastasis to regional lymph nodes remains the key prognostic factor for colon cancer. SLN mapping is feasible for colon cancer and can identify a subset of patients who could benefit from adjuvant chemotherapy. Although SLN mapping did not alter the surgical management of colon cancer, it does make possible a more focused and cost-effective pathologic evaluation of nodal disease. We do not suggest routine utilization of SLN mapping for colon cancer, but we believe that the data supports proceeding with a national trial.     

Intraoperative lymphatic mapping and the sentinel node concept in colorectal carcinoma

BACKGROUND: Orderly progression of nodal metastases has been described for melanoma and breast cancer. The first draining lymph node, the sentinel node, is also the first to contain metastases and accurately predicts nodal status. The aim of this study was to assess the feasibility of lymphatic mapping and sentinel node biopsy in colorectal cancer. METHODS: In 50 patients with colorectal cancer patent blue dye was injected around the tumour. After resection of the tumour the specimen was examined to identify blue-stained lymph nodes. Routine histopathological examination was performed on all nodes and the blue, haematoxylin and eosin-stained tumour-negative nodes were tested immunohistochemically. RESULTS: Lymphatic mapping was possible in 35 of 50 patients (70 per cent). Pathological examination with haematoxylin and eosin staining showed lymph node metastases in 20 of 35 patients. In eight of these 20 patients the blue nodes showed tumour, while in 12 the blue nodes were not involved. This represents a false-negative rate of 60 per cent. CONCLUSION: Lymphatic mapping using patent blue dye is feasible in colorectal cancer. The blue-stained nodes do not predict nodal status of the remaining lymph nodes in the resected specimen. The concept of lymphatic mapping and sentinel node identification is not valid for colorectal cancer.     

Prospective randomized study comparing sentinel lymph node evaluation with standard pathologic evaluation for the staging of colon carcinoma: results from the United States Military Cancer Institute Clinical Trials Group Study GI-01

BACKGROUND: The principal role of sentinel lymph node (SLN) sampling and ultrastaging in colon cancer is enhanced staging accuracy. The utility of this technique for patients with colon cancer remains controversial. PURPOSE: This multicenter randomized trial was conducted to determine if focused assessment of the SLN with step sectioning and immunohistochemistry (IHC) enhances the ability to stage the regional nodal basin over conventional histopathology in patients with resectable colon cancer. PATIENTS AND METHODS: Between August 2002 and April 2006 we randomly assigned 161 patients with stage I-III colon cancer to standard histopathologic evaluation or SLN mapping (ex vivo, subserosal, peritumoral, 1% isosulfan blue dye) and ultrastaging with pan-cytokeratin IHC in conjunction with standard histopathology. SLN-positive disease was defined as individual tumor cells or cell aggregates identified by hematoxylin and eosin (H&E) and/or IHC. Primary end point was the rate of nodal upstaging. RESULTS: Significant nodal upstaging was identified with SLN ultrastaging (Control vs. SLN: 38.7% vs. 57.3%, P = 0.019). When SLNs with cell aggregates < or =0.2 mm in size were excluded, no statistically significant difference in node-positive rate was apparent between the control and SLN arms (38.7% vs. 39.0%, P = 0.97). However, a 10.7% (6/56) nodal upstaging was identified by evaluation of H&E stained step sections of SLNs among study arm patients who would have otherwise been staged node-negative (N0) by conventional pathologic assessment alone. CONCLUSION: SLN mapping, step sectioning, and immunohistochemistry (IHC) identifies small volume nodal disease and improves staging in patients with resectable colon cancer. A prospective trial is ongoing to determine the clinical significance of colon cancer micrometastasis in sentinel lymph nodes.     

A novel lymphatic mapping technique to improve localization and staging of early colon cancer during laparoscopic colectomy

Encouraging results from our previous studies of sentinel lymph node (SLN) mapping in colorectal cancer (CRC) prompted investigation of its feasibility and accuracy during laparoscopic colectomy for early CRC. Between 1996 and 2000, 14 patients with clinically localized colorectal neoplasms underwent colonoscopic tattooing of the primary site and SLN mapping. In each case 0.5 to 1 cm3 of isosulfan blue dye was injected submucosally via the colonoscope. The blue-stained lymphatics were visualized through the laparoscope and followed to the SLN, which was marked with a clip, and laparoscopic colectomy was completed in the routine fashion. All lymph nodes were examined by hematoxylin and eosin (H&E) staining; in addition each SLN was subjected to focused examination by multisectioning and immunohistochemical staining using cytokeratin antibody. In all 14 patients the primary neoplasm and an SLN were identified laparoscopically. An average of 13.5 total lymph nodes and 1.7 SLNs per patient were identified. The SLN correctly reflected the tumor status of the nodal basin in 93 per cent of the cases. In four cases with unexpected lymphatic drainage, the extent of mesenteric resection was altered. In two cases (14%), nodal involvement was micrometastatic, confined to an SLN, and identified only by immunohistochemical staining. Lymphatic mapping caused no complications and added only 10 to 15 minutes to the overall operative time. Comparison of results in this group with results for a matched group of 14 patients undergoing SLN mapping during open colon resection showed that the laparoscopic technique had similar rates of accuracy and success. These preliminary findings indicate that colonoscopic/laparoscopic SLN mapping during laparoscopic colon resection is a feasible and technically simple means of identifying the primary colorectal neoplasm and its SLN. Focused pathologic examination of this node can upstage CRC and thereby may improve selection of patients for adjuvant chemotherapy.     

Sentinel node detection after preoperative short-course radiotherapy in rectal carcinoma is not reliable

BACKGROUND: Sentinel node (SN) detection may be used in patients with colonic carcinoma. However, its use in patients with rectal carcinoma may be unreliable. To address this, SN detection was evaluated in patients with rectal carcinoma after short-course preoperative radiotherapy. METHODS: Patent Blue V (1-2 ml) was injected peritumorally and submucosally directly after total mesorectal excision (TME) in 34 patients. The first one to four blue lymph nodes were categorized as SNs. All lymph nodes (non-SNs and SNs) were examined by conventional haematoxylin and eosin stained sections. If the SN was negative for metastasis, additional sections were immunostained with anticytokeratin CK7/8. In addition, SN detection was performed in 57 patients with colonic carcinoma. RESULTS: A SN was identified in 26 of 34 patients with rectal carcinoma. In three the SN was the only positive lymph node. There were six false-negative SNs (sensitivity 40 per cent) and two patients were upstaged. By contrast, SN detection was possible in 56 of 57 patient with colonic carcinoma with a sensitivity of 90 per cent, and four patients were upstaged. CONCLUSION: The SN procedure for rectal carcinoma is not reliable in combination with TME and preoperative short-course radiotherapy.     

Carbon Dye Staining of Sentinel Lymph Nodes Facilitates Microstaging of Colon Cancer Patients

Background Carbon dye, when peritumourally injected, permanently marks the drainage site of sentinel lymph nodes (SLN). The objective of the current study was to evaluate whether the use of carbon dye facilitated the detection of small nodal tumour infiltrates in colon cancer patients. Methods In a prospective trial, 19 patients underwent open, oncological resections of localized colon cancer and SLN procedure according to a standardized protocol. Isosulfan blue 1% and sterile filtered carbon dye (mixed 1:1) were injected into the subserosa circumferentially around the tumour. Lymph nodes staining blue were marked as SLN. Serial sections of each SLN were stained with hematoxylin and eosin (H&E) and with the pancytokeratin marker AE1/AE3. The intranodal presence and site of carbon particles were noted and compared with the location of possible tumour infiltrates. Results Identification of at least one SLN was successful in 18 patients (identification rate 95%). Four patients (22%) were pN+, 11 (61%) were pN0(i−). Three patients (17%) were upstaged from pN0(i−) to pN0(i+) as isolated tumour cells were detected in their SLN: in two (11%) of the three patients, carbon dye and isolated tumour cells were found in the same nodal compartment, hence facilitating the recognition of isolated tumour cells by the pathologist. Conclusion The use of carbon dye in the SLN procedure for colon cancer may facilitate the detection of small nodal tumour infiltrates. Presented at the 4th Biennial International Sentinel Node Congress, Los Angeles, CA, USA, December 3–6, 2004.     

Multiple sectioning and immunohistochemical staining of sentinel nodes in patients with breast cancer

BACKGROUND: The aim of the present study was to investigate whether focused analysis of sentinel nodes is more useful than routine haematoxylin and eosin examination of axillary lymph nodes obtained by axillary lymph node dissection. METHODS: One hundred and fifty-two patients with breast cancer with clinically negative axillary nodes underwent successful sentinel node biopsy using a combination of dye and radioisotope, followed immediately by standard level I and II axillary lymph node dissection. Multiple sectioning, with haematoxylin and eosin and immunohistochemical analysis of sentinel nodes using cytokeratin antibody, was compared with single section and haematoxylin and eosin analysis of sentinel and non-sentinel nodes (routine examination). RESULTS: A mean of 1.9 (range 1-12) sentinel nodes and 11.2 (range 4-24) non-sentinel nodes were excised per patient. Metastases were detected in 44 patients (29 per cent) by single section and haematoxylin and eosin analysis of sentinel and non-sentinel nodes. An additional five patients (3 per cent) with metastases were detected by multiple sectioning and haematoxylin and eosin analysis of sentinel nodes. A further 20 patients (13 per cent) with metastases were identified by multiple sectioning and immunohistochemical analysis of sentinel nodes. Both haematoxylin and eosin and immunohistochemical analysis of sentinel nodes missed one patient with node metastases, which led to a false-negative rate of 1 per cent. CONCLUSION: Multiple sectioning and immunohistochemical staining of sentinel nodes identified 16 per cent more patients with positive axillary lymph nodes than routine haematoxylin and eosin examination.     

Combination probe and dye-directed lymphatic mapping detects micrometastases in early colorectal cancer

Nodal metastasis is the single most important prognostic factor in early colorectal cancer (CRC). Lymphatic mapping can identify sentinel nodes for focused histopathologic examination and thereby improve the nodal staging of CRC; however, the optimal technique for identifying sentinel nodes in CRC is unclear. We hypothesized that a combination of radiotracer and blue dye would more accurately identify tumor-positive sentinel nodes than blue dye alone. Lymphatic mapping was performed in 48 consecutive patients undergoing resection for CRC and in two original patients who underwent sentinel node mapping in 1996. Prior to resection, 1% vital blue dye and radiotracer were injected around the tumor in the subserosal layer. Nodes were designated as sentinel by blue coloration and/or radioactivity. Lymphatic mapping identified at least one sentinel node in 49 patients. Focused examination of multiple sentinel node sections by means of hematoxylin and eosin and immunohistochemical analysis showed that sentinel nodes accurately predicted the status of the nodal basin in 93.8% (46 of 49) of patients. Of the 19 patients with nodal metastases, 11 had macrometastases (>.2 mm), three had micrometastases (between 2 mm and 0.2 mm), and five had isolated tumor cells or clusters (<.2 mm) identified by immunohistochemical analysis only.Patients had significantly fewer blue/radioactive (“hot”) nodes than blue-only nodes (1.38 vs. 2.48 per patient; P = 0.0001). It is important to note that nodal metastases were more common in blue/ hot nodes than in blue-only nodes (27.3% [19 of 68] vs. 8.8% [11 of 124]; P = 0.005). Dual-agent lymphatic mapping more accurately identifies sentinel node metastases than blue dye alone. In addition, this technique allows a more focused histopathologic examination of these nodes, in conjunction with the revised American Joint Committee on Cancer guidelines, and thereby offers the potential for significant upstaging of CRC. Presented at the Forty-Third Annual Meeting of The Society for Surgery of the Alimentary Tract, San Francisco, California, May 19–22, 2002 (oral presentation). Supported by grant CA090848 from the National Cancer Institute; the Rogovin-Davidow Foundation, Los Angeles, California; the Rod Fasone Memorial Cancer Fund, Indianapolis, Indiana; and U.S. Surgical Corp., Norwalk, Connecticut.     

淋巴绘图和前哨淋巴结定位在腹腔镜结肠癌切除术中的应用

目的 探讨淋巴绘图(LM)和前哨淋巴结(SLN)定位分析在腹腔镜结肠癌手术中的应用价值.方法 32例结肠癌患者,术中在纤维电子肠镜辅助下,将0.5～1.0 mL异硫蓝染剂注射在瘤体四周的黏膜下层,随即通过腹腔镜观察,蓝染的SLN清晰可见.结肠采用标准术式切除.所有淋巴结经苏木精-伊红(HE)染色,对每一个SLN进行多点取材,同时进行HE染色及抗细胞角蛋白免疫组织化学(IHC)染色双重病理检查.结果 所有患者在腹腔镜下至少识别1个SLN.94%成功检出SLN,并正确反映了该区域淋巴结的肿瘤状况.8例(25.0%)蓝染的淋巴管系超出了术前预计范围,术中实行了宽系膜切除.4例(12.5%)患者的SLN经HE染色阴性而IHC染色证实存在微转移灶.结论 SLN绘图在腹腔镜结肠癌切除术中,可以指导切除范围;联合应用IHC染色可以提高肿瘤分期,将对患者手术方式的选择和预后评估更加准确.     

One hundred consecutive cases of sentinel lymph node mapping in early colorectal carcinoma: Detection of missed micrometastases

Almost one third of patients with "node-negative" colorectal carcinoma (CRC) develop systemic disease. This implies that these patients have occult disease that is inadequately treated by surgery alone. We have coupled sentinel lymph node mapping and a focused pathologic examination to detect occult nodal micrometastases in CRC. Since 1996, sentinel lymph node mapping has been performed in 100 consecutive patients undergoing colectomy for CRC. Peritumoral injection of 0.5 to 1.0 ml of isosulfan blue dye was performed to demonstrate the sentinel node(s). All lymph nodes in the resection specimen were examined by routine hematoxylin and eosin staining. In addition, a focused examination of multiple sections of the sentinel nodes was performed using both hematoxylin and eosin and cytokeratin immunohistochemical analysis (CK-IHC). Overall, lymphatic mapping successfully demonstrated one to four sentinel lymph nodes in 97 (97%) of 100 patients. These sentinel nodes accurately reflected the status of the nodal basin in 92 (95%) of 97 patients. All five of the false negative cases occurred in T3/T4 tumors, and three of the five occurred during the first 30 cases in the experience. Unexpected lymphatic drainage was encountered in eight patients (8%) and altered the operative approach. Twenty-six patients were node positive by routine hematoxylin and eosin staining. Of the remaining 74 patients with hematoxylin and eosin-negative nodes, an additional 18 patients (24%) were upstaged by identification of occult nodal micrometastases that were missed on routine hematoxylin and eosin staining but detected on multiple sections (n = 5) or by CK-IHC (n = 13). The sentinel lymph nodes were the only positive nodes in 19 cases. Sentinel lymph node mapping may be performed in CRC with a high degree of success and accuracy. A focused pathologic examination of the sentinel node detects micrometastatic disease that is missed by conventional techniques in a significant proportion of patients with early CRC. Further studies are necessary to elucidate the clinical relevance of these micrometastases. Presented at the Forty-Second Annual Meeting of The Society for Surgery of the Alimentary Tract, Atlanta, Georgia, May 20–23, 2001 (oral presentation). Supported in part by grant T32 CA 09689 and 090848 from the National Cancer Institute and by funding from the Rogovin-Davidow Foundation, Los Angeles, California and the Rod Fasone Memorial Cancer Fund, Indianapolis, Indiana.     

Mapping sentinel nodes in patients with early-stage gastric carcinoma

BACKGROUND: Nodal status in gastric carcinoma is related not only to prognosis but also to the extent of nodal dissection. However, a method for accurate assessment of nodal status during operation has not been established. This study aimed to map the sentinel nodes of gastric carcinoma and to estimate the clinical usefulness of sentinel node biopsy. METHODS: Following laparotomy, a vital dye (0.2 ml 2 per cent patent blue) was injected through a gastroscope into the submucosal layer at four sites around a clinical T1 gastric carcinoma. The dye immediately appeared at the serosal surface and stained lymphatic vessels and nodes. The stained nodes were removed and examined by frozen sectioning. RESULTS: The assay was successful in mapping the lymphatic basins in 203 (96.2 per cent) of 211 patients. The dye stained one or more metastatic nodes in 31 patients, but failed to indicate a metastatic node in four patients with a large involved node. Meticulous postoperative examination of all resected nodes in the standard paraffin slices revealed no new metastases. The accuracy of the assay was 98.0 per cent. CONCLUSION: The method was accurate in predicting nodal status in patients with early-stage gastric carcinoma.     

Evaluation of axillary lymph nodes using touch imprint cytology and immunohistochemistry

BACKGROUND: The success of sentinel node biopsy in determining axillary lymph node status necessitates an accurate and rapid method for intraoperative examination of the nodes. The aim was to determine the feasibility and accuracy of immunohistochemistry (IHC) of touch imprints in detecting axillary nodal metastases intraoperatively. METHODS: Some 344 axillary nodes from 30 patients with early breast cancer were bisected, imprinted and subjected to IHC. Results were compared with those of routine haematoxylin and eosin examination of the same nodes. RESULTS: Using IHC, 29 nodes from nine patients were positive for metastases. Using haematoxylin and eosin, 28 nodes from eight patients were positive. On a patient basis, the sensitivities of IHC and haematoxylin and eosin were 100 and 88.9 per cent, and negative predictive values (NPVs) were 100 and 95.5 per cent, respectively. On a node basis, the sensitivities were 96.7 and 93.3 per cent, and NPVs were 99.7 and 99.3 per cent, respectively. There were no false positives. The results were obtained within 30-45 min, depending on the number of nodes examined. CONCLUSION: IHC of touch imprints can provide a fast and sensitive method for detecting metastases in axillary nodes during breast cancer surgery.     

Effect of increasing the surface sampled by imprint cytology on the intraoperative assessment of axillary sentinel lymph nodes in breast cancer patients

As axillary sentinel nodes predict the nodal status and may allow dissection of the axilla on a selective basis we assessed the effects of increasing the surface sampled during intraoperative imprint cytology. Sentinel nodes from 110 patients identified with Patent blue and/or the high radioactivity due to the uptake of 99m-Tc-labeled colloidal albumin were analyzed via hematoxylin and eosin-stained touch preparations. Imprint cytology was performed either on bisected nodes (Protocol One; n = 55) or on sentinel nodes sliced into multiple pieces at 2- to 3-mm intervals (Protocol Two; n = 55). The sentinel nodes were submitted in toto to permanent step sectioning and immunostaining for cytokeratins. There were equal numbers of patients with involved nodes in the two groups assessed. With Protocols One and Two the imprints had sensitivities of 52 and 61 per cent, negative predictive values of 74 and 78 per cent, and false negative rates of 47 and 39 per cent, respectively. No macrometastasis missed by Protocol Two was absent from the surface sampled. These data suggest that increasing the surface sampled improves the proportion of involved sentinel nodes detected intraoperatively by imprint cytology, but a number of metastatic nodes still remain undetected by this method. The sampling of multiple surfaces is encouraged for a more accurate intraoperative assessment.     

Sentinel lymph node dissection for primary cutaneous melanoma: a community hospital's initial experience

Management of the regional lymph nodes remains the most controversial aspect of treating patients with intermediate-thickness cutaneous melanoma. Prospective studies have failed to demonstrate a significant survival advantage for patients undergoing elective lymph node dissection. The sentinel lymph node dissection (SLND) technique has been proposed as a method of accurately identifying patients with occult metastases in whom a regional lymph node dissection would be indicated. The majority of studies evaluating this technique have come from academic centers, most with dedicated melanoma clinics. This report describes the initial experience with SLND at a community hospital. Fifteen patients with intermediate-thickness primary cutaneous melanoma underwent preoperative lymphoscintigraphy with 99Tc-sulfur colloid. In addition, intraoperative lymphatic mapping using intradermally injected isosulfan blue was performed. Dissection was guided by radioactivity levels (in counts per second) as measured by a hand-held gamma probe. The resected lymph node or nodes were evaluated for micrometastases using routine hematoxylin and eosin staining and immunohistochemistry with S-100 and HMB-45. All patients were followed clinically for any evidence of recurrence. A sentinel node(s) was identified on preoperative lymphoscintigraphy in all 15 patients (100%). A single sentinel node was identified in 11 of 15 (73%), two nodes in 3 (20%), and one node in 1 (6.7%). The hand-held gamma probe reading correlated well with the site marked the "hot spot" (600-15,320 cps for the hot spot versus 10-350 cps for background). The sentinel lymph node was successfully identified and resected in all 15 patients. Blue-stained lymphatics and/or lymph nodes were present in 8 of 15 (53%) cases. Histopathology was negative for evidence of occult micrometastases in all patients. At mean follow-up of 221 days, all 15 patients remain with no evidence of disease. The outcomes for mapping and harvesting the sentinel node at a community institution compare favorably with results at major academic institutions. SLND may therefore be offered to patients with intermediate-thickness cutaneous melanoma in the community hospital setting with regional lymph node dissection and adjuvant interferon alpha-2b as options for patients with nodal micrometastases.     

Validation of Lymphatic Mapping in Colorectal Cancer: In Vivo, Ex Vivo, and Laparoscopic Techniques

Background:The use of lymphatic mapping (LM) is being investigated to improve the staging of colorectal cancer (CRC) and thereby identify patients who might benefit from adjuvant chemotherapy. This study evaluated in vivo, laparoscopic, and ex vivo approaches for the ultrastaging of CRC.Methods:Seventy-five CRC patients were enrolled in a study of LM with peritumoral injection of isosulfan blue dye. LM was undertaken during open colon resection (OCR) in 64 patients, during laparoscopic colon resection (LCR) in 9 patients, and after specimen removal (ex vivo) in 2 patients. Ex vivo LM was also undertaken in 6 patients after unsuccessful in vivo LM. All nodes were examined by hematoxylin and eosin (H&E) staining; in addition, sentinel lymph nodes (SNs) were multisectioned and examined by immunohistochemical staining with cytokeratin (CK-IHC).Results:At least one SN was identified in 72 patients (96%). In vivo LM identified SNs in 56 of 64 (88%) patients undergoing OCR and in 9 of 9 (100%) patients undergoing LCR. Ex vivo LM was undertaken as the initial mapping procedure in 2 cases of intraperitoneal colon cancer and after in vivo LM had failed in 6 cases of extraperitoneal rectal carcinoma; an SN was identified in 7 of the 8 cases. Focused examination of the SN correctly predicted nodal status in 53 of 56 OCR cases, 9 of 9 LCR cases, and 6 of 7 ex vivo cases. Multiple sections and CK-IHC identified occult micrometastases in 13 patients (17%), representing 10 OCR, 1 LCR, and 2 ex vivo cases.Conclusions:LM of drainage from a primary CRC can be accurately performed in vivo during OCR or LCR. Ex vivo LM can be applied when in vivo techniques are unsuccessful and may be useful for rectal tumors. During LCR, colonoscopic injection can be used to mark the primary tumor and define the lymphatic drainage so that adequate resection margins are obtained. These LM techniques improve staging accuracy in CRC.Presented at the 53rd Annual Meeting of the Society of Surgical Oncology, New Orleans, Louisiana, March 16-19, 2000     

Survival benefit of high ligation of the inferior mesenteric artery in sigmoid colon or rectal cancer surgery

BACKGROUND: The aim of this study was to assess the impact of inferior mesenteric artery (IMA) root nodal dissection before high ligation of the artery on survival in patients with sigmoid colon or rectal cancer. METHODS: Data on 1188 consecutive patients who underwent resection for sigmoid colon or rectal cancer, with high ligation of the IMA, were identified from a prospective database (April 1965 to December 1999). Survival of patients with involvement of nodes along the IMA proximal to the origin of the left colic artery (root nodes, station 253) through the bifurcation of the superior rectal artery (trunk nodes, station 252) was determined. RESULTS: Twenty patients (1.7 per cent) had metastatic involvement of station 253 lymph nodes and 99 (8.3 per cent) had metastases to station 252. The 5- and 10-year survival rates of patients with metastases to station 253 were 40 and 21 per cent, and those for patients with metastases to station 252 were 50 and 35 per cent, respectively. CONCLUSION: High ligation of the IMA allows curative resection and long-term survival in patients with cancer of the sigmoid colon or rectum and nodal metastases at the origin of the IMA.