A detailed histological study on occult metastasis of the lymph nodes

Limited Clinical Significance of Splenectomy and Splenic Hilar Lymph Node Dissection for Type 4 Gastric Cancer

Purpose

Type 4 gastric cancer (GC) has a very poor prognosis even after curative resection, and the survival benefit of splenectomy for splenic hilar lymph node (LN; #10) dissection in type 4 GC remains equivocal. This study aimed to clarify the clinical significance of splenectomy for #10 dissection in patients with type 4 GC.

Materials and Methods

The data of a total of 56 patients with type 4 GC who underwent total gastrectomy with splenectomy were retrospectively analyzed. Postoperative morbidity, state of LN metastasis, survival outcomes, and therapeutic value index (TVI) of each LN station were evaluated. TVI was calculated by multiplying the incidence of LN metastasis at each nodal station and the 5-year overall survival (OS) of patients who had metastasis to each node.

Results

Overall, the postoperative morbidity rate was 28.6%, and the incidence of #10 metastasis in the patients was 28.6%. The 5-year OS rate for all patients was 29.9%, and most patients developed peritoneal recurrence. Moreover, the 5-year OS rates with and without #10 metastasis were 6.7% and 39.1% (median survival time, 20.4 vs. 46.0 months; P=0.006). The TVI of #10 was as low as 1.92.

Conclusions

The clinical significance of splenectomy in the dissection of #10 for type 4 GC is limited and splenectomy for splenic hilar dissection alone should be omitted.

Nodal metastasis in well-differentiated follicular carcinoma of the thyroid: Its incidence and clinical significance

The clinical significance of nodal metastasis in well-differentiated follicular carcinoma (WD-FC) of the thyroid remains a controversial issue. This study aimed to clarify clinical and pathological characteristics of WD-FC with nodal metastasis, based on the new WHO classification. We examined 249 WD-FC cases diagnosed between 1983 and 2004 in our hospital. Poorly differentiated follicular carcinoma was not included in this study. Of the 249 WD-FC cases, 9 (3.6%) revealed nodal metastasis. The incidences of nodal metastasis in minimally invasive and widely invasive cases were 2.0 and 9.8%, respectively. In four patients, nodal metastasis was detected in the ipsilateral lymph nodes during the initial surgery. A total of 6 patients presented with nodal metastasis 2-10 years after the initial operation, and 3 patients with bilateral and large nodal metastases were relatively young. No patients succumbed to the carcinoma. Primary lesions of WD-FC with nodal metastasis were microscopically conventional, and there were no findings predicting nodal metastasis. We hypothesized that the incidence of nodal metastasis in WD-FC, based on the new WHO classification, was lower compared with previous reports. Younger individuals may be at a higher risk of large bilateral nodal metastasis. The presence of nodal metastasis did not affect the long-term outcome of follicular carcinoma.

Prognostic significance of occult lymph node micrometastasis in gastric cancer: a histochemical and immunohistochemical study based on 1997 UICC TNM and 1998 JGCA classifications

BACKGROUND: Micrometastasis is a single or a cluster of malignant cells inside the lymph node that are not detected by routine histopathological sections. Micrometastasis is related to poorer prognosis in many gastric cancer studies the real significance of these cells is still controversial. AIM: To evaluate if lymph node micrometastasis is a significant independent prognostic factor and important risk factor for recurrence in gastric cancer. METHODS: A total of 1290 lymph nodes from 28 patients with gastric cancer, since 1998 until 2003, treated by radical resection (D2 and modified D3 lymphadenectomies) were studied. Three sections per lymph node were stained by Hematoxilin-Eosin, histochemical (AB-PAS) and immunohistochemical (AE1-AE3) techniques. Kaplan-Meier's survival curves and Log-rank/Cox tests were used in order to compares lymph node micrometastasis positivity, depth (pT) and location of tumor in gastric wall, histologic type, lymphatic, vascular and perineural invasion, lymph node status (pN) and stage. RESULTS: There were worse prognosis and recurrence in patients with positive lymph node micrometastasis related to vascular and perineural invasions, advanced lymph node status and advanced stages. CONCLUSION: Lymph node micrometastasis seems to be a significant independent prognostic factor and important risk factor for recurrence in gastric cancer, in a context of radical D2 lymphadenectomy

Histopathological assessment of lymph nodes in colorectal carcinoma: does triple levelling detect significantly more metastases?

AIMS

Standard practice is to take one section from every lymph node found in colorectal carcinoma resection specimens, to look for metastatic carcinoma. This study evaluates whether assessing three sections separated by 100 microm detects significantly more metastases in nodes than the conventional single section.

METHODS

A retrospective study of 100 colorectal carcinoma resection specimens. All blocks containing lymph nodes had two extra histological sections cut (separated by 100 microm) and stained with haematoxylin and eosin. The original slide was called level 1, and the extra two sections levels 2 and 3.

RESULTS

Twenty Dukes's A (equivalent to WHO-UICC stage grouping I, pTNM stage pT1/2N0), 43 Dukes's B (equivalent to WHO-UICC stage grouping II, pTNM stage pT3/4N0), and 37 Dukes's C (equivalent to WHO-UICC stage grouping III, pTNM stage at least pN1) cases were examined (total 1453 nodes). Twelve extra metastases (in 11 patients) were discovered in nodes at levels 2 and 3, which were negative in level 1. Ten cases were Dukes's C and, in one patient, this led to upstaging from N1 to N2 (pTNM classification system). One case was Dukes's B and the discovery of a single metastasis on level 2 upstaged it to Dukes's C.

CONCLUSIONS

Triple levelling detected more tumour deposits than the conventional single section. In two patients, the staging classification of the lesion was changed, with potentially important implications for prognosis and management.

Sentinel lymph node mapping in colon cancer

BACKGROUND

By systematically reviewing the literature on sentinel lymph node mapping of colon cancers, this study aimed to evaluate this technique as it applies to colon cancers.

METHODS

Human studies on lymphatic mapping for colon cancers were reviewed. Multiple publications of the same studies, abstracts, and case reports were excluded. Current Contents, MEDLINE, EMBASE, and Cochrane Library databases were investigated.

RESULTS

Lymphatic mapping appears to be readily applicable to colon cancers, identifying lymph nodes most likely to harbor metastases. Identification of sentinel lymph nodes varied from 58% to 100% and carried a false-negative rate of approximately 10% in larger studies, but potentially rose 4% to 25% among patients representing a range from node-negative to node-positive (micrometastases) conditions. The prognostic implication of these micrometastases requires further evaluation. Lymphatic mapping in 6% to 29% of cases identified aberrant lymphatic drainage that altered the extent of the lymphadenectomy.

CONCLUSIONS

Further follow-up evaluation to assess the prognostic significance of micrometastases for colon cancers is required before the staging benefits of sentinel node mapping can have therapeutic implications. Lymphatic mapping offers the possibility of improving staging by identifying patients with early disseminated disease who should be considered for adjuvant treatment or included in trials of adjuvant treatment to speed up the breakthrough of more effective adjuvant regimens. Large studies are needed to determine whether the sentinel node concept is as valid for colon cancers as studies so far have shown it is for malignant melanoma and breast cancer.

Pathologic evaluation of sentinel lymph nodes in colorectal carcinoma

BACKGROUND

The identification of lymph node metastases in colorectal resection specimens is necessary for accurate tumor staging. However, routine lymph node dissection by the pathologist yields only a subset of nodes removed surgically and may not include those nodes most directly in the path of lymphatic drainage from the tumor. Intraoperative mapping of such sentinel lymph nodes (SLNs) has been reported in cases of melanoma and breast cancer. We applied a similar method to cases of colorectal carcinoma, with emphasis on the pathology of the SLNs.

METHODS

Eighty-three consecutive patients with colorectal carcinoma were evaluated after intraoperative injection of 1 to 2 mL of 1% isosulfan blue dye (Lymphazurin) into the peritumoral subserosa. Blue-stained lymph nodes were suture-tagged by the surgeon within minutes of the injection for identification by the pathologist, and a standard resection was performed. Designated SLNs were sectioned at 10 levels through the block; a cytokeratin immunostain (AE1) was also obtained. To evaluate the possibility that increased detection of metastases in the SLN might be solely due to increased histologic sampling, all initially negative non-SLNs in the first 25 cases were sectioned also at 10 levels.

RESULTS

Sentinel lymph nodes were identified intraoperatively in 82 (99%) of 83 patients and accounted for 152 (11.9%) of 1275 lymph nodes recovered, with an average of 1.9 SLNs per patient. A total of 99 positive lymph nodes (38 positive SLNs and 61 positive non-SLNs) were identified in 34 node-positive patients. The SLNs were the only site of metastasis in 17 patients (50%), while 14 patients (41%) had both positive SLNs and non-SLNs. Three patients (9%) had positive non-SLNs with negative SLNs, representing skip metastases. In patients with positive SLNs, 91 (19%) of 474 total lymph nodes and 53 (12%) of 436 non-SLNs were positive for metastasis. In patients with negative SLNs, 8 (1%) of 801 total lymph nodes and 8 (1.2%) of 687 non-SLNs were positive for metastasis. Multilevel sections of 330 initially negative non-SLNs in the first 25 patients yielded only 2 additional positive nodes (0. 6%). All patients with positive SLNs were correctly staged by a combination of 4 representative levels through the SLN(s) together with a single cytokeratin immunostain.

CONCLUSIONS

Intraoperative mapping of SLNs in colorectal carcinoma identifies lymph nodes likely to contain metastases. Focused pathologic evaluation of the 1 to 4 SLNs so identified can improve the accuracy of pathologic staging.

Clinical significance of lymph node micrometastasis of pN0 esophageal squamous cell carcinoma

The lymph nodes of 59 patients with pN0 esophageal squamous cell carcinomas were examined immunohistochemically using cytokeratin (CK) antibody. Primary tumors were immunostained with cyclin D1 (CD1) and E-cadherin (E-cad) antibody. Lymph node micrometastasis (MM) was found in 39 (55.5%) patients. Tumor recurrence was found in 17 patients and all but one of them had MM. The 5-year survival rate was significantly poorer in patients with MM than in those without MM. Almost all patients with positive CD1 and negative E-cad expression had MM. The examination of CD1 and E-cad expression in primary tumors may be useful for predicting MM.

Ignoring small lymph nodes can be a major cause of staging error in gastric cancer

BACKGROUND

Stage migration in gastric cancer confounds establishment of standard treatment according to stage.

METHODS

To determine how closely lymph nodes should be examined to report correct staging, 402 node-positive patients were evaluated retrospectively. A total of 23,233 lymph nodes were reviewed histologically and their maximum dimension was measured. Another 254 nodes from 12 patients were used to evaluate shrinkage after fixation and preparation of the histological slide.

RESULTS

Metastasis was detected in 3142 nodes, 1163 with well differentiated tumours (WDTs) and 1979 with poorly differentiated tumours (PDTs). Mean(s.d.) size of metastatic nodes was 7.80(5.08) mm in all, 8.44(5.74) mm in WDTs and 7.42(4.62) mm in PDTs. Both positive and negative nodes shrank between 10 and 20 per cent during histological processing. If all nodes 5 mm or less in size when fixed are ignored 37.8 per cent of all metastatic nodes will be missed. Downstaging will occur in 14.9 per cent and 4.2 per cent of the cases if all nodes less than 6 and 4 mm respectively are ignored.

CONCLUSION

To keep the rate of stage migration caused by this factor below 5 per cent, all lymph nodes 4 mm or more in size (5 mm when fresh) should be retrieved and examined.

Extranodal connective tissue invasion and the expression of desmosomal glycoprotein 1 in squamous cell carcinoma of the oesophagus

We investigated extranodal connective tissue involvement (ECTI) in 39 patients with oesophageal carcinoma. Both the primary tumour and ECTI were immunohistochemically examined using the monoclonal antibody 32-2B for desmosomal glycoprotein 1 (DG1). Connective tissue carcinoma deposits were identified as cells within small lymph nodes, as lymphatic or venous vessel invasion or as widespread invasion beyond the capsule of metastatic lymph nodes. These histological findings were present in at least one area in 20 of 39 patients (51.3%). DG1 immunostaining intensity by tumour was graded as DG1 (++), DG1 (+) or DG1 (-). DG1 (+) or DG1 (-) primary tumours demonstrated lymph node metastases and ECTI more frequently than DG1(++) tumours (P<0.05). Among 17 patients in whom DG1 immunohistochemistry was performed on ECTI, there were three DG1(++), five DG1(+) and nine DG1(-) patients. The DG1 expression of ECTI was equal to or less intense than the primary tumour. These results indicate that reduction or loss of DG1 expression may promote ECTI and lymph node metastases. One should be aware of the potential for ECTI in oesophageal carcinomas. In the future, adjuvant therapy may be advisable for some oesophageal carcinomas based on the phenotype of individual cancer cells, including expression of DG1.

New method to evaluate the therapeutic value of lymph node dissection for gastric cancer

The results of 1281 potentially curative resections for advanced gastric cancer performed at the National Cancer Center Hospital between 1972 and 1986 were studied using a novel approach which circumvents the stage migration phenomenon. The incidence of metastasis and the 5-year survival rate of patients with positive nodes were calculated independently for each lymph node 'station', without any reference to overall pathological nodal stage. The therapeutic value of extended lymph node dissection was estimated by multiplication of incidence of metastasis and percentage 5-year survival rate of patients with metastasis for each station. The incidence of metastasis ranged from 2.4 per cent to 66 per cent and the 5-year survival rate of affected patients from 0 to 58.7 per cent in perigastric stations, depending on the site of the primary tumour. The incidence of metastasis was between 3.0 per cent and 44.4 per cent in the second tier of nodes (n2), and the 5-year survival rate ranged from 0 per cent to 47.5 per cent. The majority of second-tier stations showed evidence of benefit from node dissection.

Occult lymph node metastasis in gastric cancer with submucosal invasion

To evaluate more precisely the incidence of lymph node metastasis in patients with submucosally invaded (sm) gastric cancer, three additional sections were made from the remaining half of 1,794 lymph nodes taken from 57 patients, for a detailed reexamination. Lymph node metastasis was demonstrated in 19 nodes from 11 patients by the initial routine examination; however, the detailed reexamination showed cancer involvement in a further nine lymph nodes from eight patients. Of these eight patients, metastasis had not been detected in any lymph nodes by routine examination in six. Macroscopically, the lesion was of the depressed or mixed type in six of the eight patients. From the intranodal location and growth pattern of the cancer foci, lymph nodes with occult metastasis were divided into the marginal sinus type, the medullary sinus type, and the mixed type, with the marginal type being found most frequently. The overall incidence of lymph node metastasis in patients with sm gastric cancer was as high as 29.8% (17/57) in this series. Moreover, a follow-up study revealed that two patients with occult metastasis died of cancer recurrence postoperatively. Accordingly, systematic regional lymph node dissection should be carried out at the time of surgery for sm gastric cancer.