Lymphatic Map Research Articles

Lymphatic Mapping with Multi-Lymphosome Indocyanine Green Lymphography in Legs with Lymphedema.

It is observed that the locations of the most functional lymphatic vessels in the lymphedematous limbs can differ significantly from those in healthy limbs. The aim of this study was to elucidate the lymphatic map of lymphedematous limbs. We retrospectively analyzed 59 patients (118 limbs) with lower limb lymphedema. Fifty-five were women and four were men. The mean age and duration of lymphedema was 62.4 and 7.7 years, respectively. For the lateral thigh lymphosome, we injected indocyanine green (ICG) at the lateral knee and measured the distance (Dt) between the anterior superior iliac spine (ASIS) and the point where the lymphatic vessels crossed the reference line (the line connecting the ASIS and the patellar center). For the lateral calf lymphosome, we injected ICG at the lateral ankle and measured the distance (Dc) between the inferior patellar border and the point where the lymphatic vessels crossed the reference line (the anterior border of the tibia). In the lateral thigh, the mean Dt was 30.4 ± 0.6 cm (range, 0-41 cm) and the distribution peaked at approximately 30 cm from the ASIS. In the calf, the mean Dc was 13.1 ± 0.9 cm (range, -11 to 32 cm). The distribution of lymphatic vessel locations was highly variable. We could establish the lymphatic map in the lymphedematous legs. The distribution of lymphatic vessels in the thigh and lower legs had one and two peaks, respectively.

Lymphatic mapping for image-guided radiotherapy in patients with locally advanced uterine cervical cancer: a feasibility study

BackgroundLymph node metastasis is an important prognostic factor in locally advanced cervical cancer (LACC). No imaging method can successfully detect all (micro)metastases. This may result in (lymph node) recurrence after chemoradiation. We hypothesized that lymphatic mapping could identify nodes at risk and if radiation treatment volumes are adapted based on the lymphatic map, (micro)metastases not shown on imaging could be treated. We investigated the feasibility of lymphatic mapping to image lymph nodes at risk for (micro)metastases in LACC and assessed the radiotherapy dose on the nodes at risk.MethodsPatients with LACC were included between July 2020 and July 2022. Inclusion criteria were: ≥ 18 years old, intended curative chemoradiotherapy, investigation under anesthesia. Exclusion criteria were: pregnancy and extreme obesity. All patients underwent abdominal MRI, [18F]FDG-PET/CT and lymphatic mapping after administration of 6–8 depots of 99mTc]Tc-nanocolloid followed by planar and SPECT/CT images 2–4 and 24 h post-injection.ResultsSeventeen patients participated. In total, 40 nodes at risk were visualized on the lymphatic map in 13/17 patients with a median of two [range 0–7, IQR 0.5–3] nodes per patient, with unilateral drainage in 4/13 and bilateral drainage in 9/13 patients. No complications occurred. The lymphatic map showed more nodes compared to suspicious nodes on MRI or [18F]FDG-PET/CT in 8/14 patients. Sixteen patients were treated with radiotherapy with 34 visualized nodes on the lymphatic map. Of these nodes, 20/34 (58.8%) received suboptimal radiotherapy: 7/34 nodes did not receive radiotherapy at all, and 13/34 received external beam radiotherapy (EBRT), but no simultaneous integrated boost (SIB).ConclusionLymphatic mapping is feasible in LACC. Almost 60% of nodes at risk received suboptimal treatment during chemoradiation. As treatment failure could be caused by (micro)metastasis in some of these nodes, including nodes at risk in the radiotherapy treatment volume could improve radiotherapy treatment outcome in LACC.Trail registration The study was first registered at the International Clinical Trial Registry Platform (ICTRP) under number of NL9323 on 4 March 2021. Considering the source platform was not operational anymore, the study was retrospectively registered again on February 27, 2023 at CilicalTrials.gov under number of NCT05746156.

Lymphatic drainage map of the head and neck skin squamous cell carcinoma detected by sentinel lymph node biopsy.

Squamous cell carcinoma of the skin often affects the scalp and neck region and has a potential for complex lymphatic metastases. The aim of this study was to examine the pattern of lymphatic drainage that would enable better insight and prediction of lymphatic metastasis of head and neck squamous cell carcinoma (HNSCC) in relation to the anatomical localization of the primary process. A prospective analysis included 64 patients who underwent sentinel lymph node (SLN) biopsy. The biopsy was performed in patients with high-risk cutaneous head and neck squamous cell carcinoma between 2006 and 2010. SLNs in tumors of the forehead, temporal region, lateral cheek, and auricle were found in the cervical region at level II and parotid lymph nodes (p<0.001). In tumors of the nose, periorbital region, and postauricular tumors, SLNs were found in parotid lymph nodes (p<0.001), in tumors of the medial cheek in level I cervical lymph nodes and parotid lymph nodes (p=0.003). In tumors of the neck, SLNs were detected in the cervical region at level IV, whereas in tumors of the posterior scalp they were found in the occipital region (p<0.001). The results of SLN biopsy in high-risk cutaneous HNSCCs show the regularity of metastasis based on which a lymphatic drainage map can be constructed and thus potential metastatic sites depending on the primary tumor localization predicted.

Usefulness of histological superstudy of sentinel lymph nodes detected with radioisotopes in colon cancer

IntroductionAdjuvant chemotherapy (CT) significally reduces the rate of relapse in +pN (stage III) colon cancer (CC) and in some pN0 (stage II) with risk factors such as pT4, vascular invasion V1, perineural invasion Pn1, and complicated tumors. However, unexpectedly, 20%–30% of pN0 present a relapse in the follow-up, which may suggest that the lymph node involvement was not discovered in the conventional histological study (CS), and its finding with a superstudy (SS) could increase the number of patients who would benefit from neoadjuvant CT. It is not possible to perform this SS in every lymph node (LN) from the specimen, but it is possible in a small group of LN which are representative of the N status (definition of sentinel node SN). The aim of our work is to state the representativeness of the SN and to analyze de number of patients who are suprastaged after the SS of the SN. Material and MethodsProspective study of a series of patients who have undergone curative surgery for CC, to whom we perform selective biopsy of sentinel node (SBDN). Identification of SN was carried out with in vivo injection of the radiotracer, with ex vivo isolation of SN. Once the specimen is out, we take pictures of the surgical bed to rule out the presence of aberrant drainage routes, out of the routine oncological resection area. We performed the histological CS (Hematoxilin-Eosin stain (H-E) in conventional sections) in the rest of the LN from the mesocolon. In the SN we performed the CS and a SS with H-E in serial sections, immunohistochemistry (IHC) and molecular study with OSNA® (One Step Nucleic Acid Amplification). Diagnostic validity study od SBSN was carried out, defining the false negative (FN) as the negativity of the SN while other LN are positive (N+), as well as a valuation of the suprastaging due to the SS of the SN. ResultsWe performed lymphatic map in 72 patients, finding the SN in 62 of them (87.3%). The 9 identification failures happened in the first 17 cases. We have not found aberrant drainage routes. A total of 1.164 LN were studied in the 62 patients (18.8 LN/patient), from which 145 are SN (2,34 SN/patient), having found 103 positive LN with the CS and 112 positive with the SS of SN (9+ LN more in 8 patients than detected with the CS). Positivity after CS in the SN group is 17.24% (25/145), while it is 8.53% in the rest (87/1.019) (P < .001). With the CS, 50% of the patients (31/62) were pN+ (4 are N+ exclusively in the SN), and after the SS of the SN, only 1 of the 31 pN0 patients (3.2%) becomes pN1a, with a definitive 51.6% of N+ in the whole series (32 N+ in the 62 patients) (5 are N+ exclusively in the SN).Exclusively with the SS of the SN, FN rate (“-SN, +others”, meaning patients who are N+ having -SN) is 54.8% (17/31). With the SS of the SN, 8 of the 62 patients (12.9%) increase their total number of +LN: apart from the patient who turns from pN0 to pN1a, suprastaging from IIA to IIIB (and therefore increasing the total number of pN+ to 32), 5 of the 17 FN in the CS turns into positive (2 change the pN subindex and one is suprastaged from IIIB to IIIC), decreasing FN to 37.5% (12/32 cases). Besides, 2 patients whose SN is already positive in the CS increase the number of +SN after the SS of the SN, therefore both changing their pN subindex and one of them suprastaging from IIIB to IIIC. In summary, 8 patients increase the total number of positive SN after the SS (8/62, 12.9%), 5 of them changing the pN subindex (5/62, 12.9%), even if only 3 of them get suprastaged (3/62, 4.8%), among them the one who turns from pN0 to pN1a. ConclusionTechnique is valid and reproducible, with a high detection rate even with a high learning curve. It globally increases the number of affected LN in 12.9% of patients, having prognostic implications in 4.8% (suprastaging rate). Only 3.2% of pN0 patients in the CS turn to be +pN after the SS of the SN, with its therapeutic implications (prescription of adjuvant CT), which could be relevant when extrapolated to a big number of patients. The high FN rate (37.5%) prevents us from accepting the representativeness of SN as the global N status, but it is not clinically relevant in CC, as its aim is not to avoid lymphadenectomy, which remains mandatory (opposite to breast cancer or melanoma in which SN detection decides upon whether to perform or not the lymphadenectomy), but to decide which patients would benefit from adjuvant CT.

Utilidad del superestudio anatomopatológico de ganglio centinela detectado con radioisótopos en el cáncer de colon

IntroductionAdjuvant chemotherapy (CT) significally reduces the rate of relapse in +pN (stage III) colon cancer and in some pN0 (stage II) with risk factors such as pT4, vascular invasion V1, perineural invasion Pn1, and complicated tumors. However, unexpectedly, 20-30% of pN0 present a relapse in the follow-up, which may suggest that the lymph node involvement was not discovered in the conventional histological study (CS), and its finding with a superstudy (SS) could increase the number of patients who would benefit from neoadjuvant CT. It is not possible to perform this SS in every lymph node (LN) from the specimen, but it is possible in a small group of LN which are representative of the N status (definition of sentinel node SN). The aim of our work is to state the representativeness of the SN and to analyze de number of patients who are suprastaged after the SS of the SN. Material and methodsProspective study of a series of patients who have undergone curative surgery for colon cancer, to whom we perform selective biopsy of sentinel node. Identification of SN was carried out with in vivo injection of the radiotracer, with ex vivo isolation of SN. Once the specimen is out, we take pictures of the surgical bed to rule out the presence of aberrant drainage routes, out of the routine oncological resection area. We performed the histological CS (hematoxilin-eosin stain in conventional sections) in the rest of the LN from the mesocolon. In the SN we performed the CS and a SS with hematoxilin-eosin in serial sections, immunohistochemistry (IHC) and molecular study with One Step Nucleic Acid Amplification (OSNA®). Diagnostic validity study od selective biopsy of sentinel node was carried out, defining the false negative (FN) as the negativity of the SN while other LN are positive (N+), as well as a valuation of the suprastaging due to the SS of the SN. ResultsWe performed lymphatic map in 72 patients, finding the SN in 62 of them (87.3%). The 9 identification failures happened in the first 17 cases. We have not found aberrant drainage routes. A total of 1.164 LN were studied in the 62 patients (18.8 LN/ patient), from which 145 are SN (2,34 SN/ patient), having found 103 positive LN with the CS and 112 positive with the SS of SN (9 +LN more in 8 patients than detected with the CS). Positivity after CS in the SN group is 17.24% (25/145), while it is 8.53% in the rest (87/1.019) (p<.001). With the CS, 50% of the patients (31/62) were pN+ (4 are N+ exclusively in the SN), and after the SS of the SN, only 1 of the 31 pN0 patients (3.2%) becomes pN1a, with a definitive 51.6% of N+ in the whole series (32 N+ in the 62 patients) (5 are N+ exclusively in the SN).Exclusively with the SS of the SN, FN rate (“-SN, +others”, meaning patients who are N+ having -SN) is 54.8% (17/31). With the SS of the SN, 8 of the 62 patients (12.9%) increase their total number of +LN: apart from the patient who turns from pN0 to pN1a, suprastaging from IIA to IIIB (and therefore increasing the total number of pN+ to 32), 5 of the 17 FN in the CS turns into positive (2 change the pN subindex and one is suprastaged from IIIB to IIIC), decreasing FN to 37.5% (12/32 cases). Besides, 2 patients whose SN is already positive in the CS increase the number of +SN after the SS of the SN, therefore both changing their pN subindex and one of them suprastaging from IIIB to IIIC. In summary, 8 patients increase the total number of positive SN after the SS (8/62, 12.9%), 5 of them changing the pN subindex (5/62, 12.9%), even if only 3 of them get suprastaged (3/62, 4.8%), among them the one who turns from pN0 to pN1a. ConclusionTechnique is valid and reproducible, with a high detection rate even with a high learning curve. It globally increases the number of affected LN in 12.9% of patients, having prognostic implications in 4.8% (suprastaging rate). Only 3.2% of pN0 patients in the CS turn to be +pN after the SS of the SN, with its therapeutic implications (prescription of adjuvant CT), which could be relevant when extrapolated to a big number of patients. The high FN rate (37.5%) prevents us from accepting the representativeness of SN as the global N status, but it is not clinically relevant in colon cancer, as its aim is not to avoid lymphadenectomy, which remains mandatory (opposite to breast cancer or melanoma in which SN detection decides upon whether to perform or not the lymphadenectomy), but to decide which patients would benefit from adjuvant CT.

Mapping the spreading routes of lymphatic metastases in human colorectal cancer

Lymphatic metastases are closely associated with tumor relapse and reduced survival in colorectal cancer (CRC). How tumor cells disseminate within the lymphatic network remains largely unknown. Here, we analyze the subclonal structure of 94 tumor samples, covering the primary tumors, lymph node metastases (LNMs), and liver metastases from 10 CRC patients. We portray a high-resolution lymphatic metastatic map for CRC by dividing LNMs into paracolic, intermediate, and central subgroups. Among the 61 metastatic routes identified, 38 (62.3%) are initiated from the primary tumors, 22 (36.1%) from LNMs, and 1 from liver metastasis (1.6%). In 5 patients, we find 6 LNMs that reseed 2 or more LNMs. We summarize 3 diverse modes of metastasis in CRC and show that skip spreading of tumor cells within the lymphatic network is common. Our study sheds light on the complicated metastatic pattern in CRC and has great clinical implications.

Feasibility of fluorescence lymph node imaging in colon cancer: FLICC.

In colon cancer, appropriate tumour excision and associated lymphadenectomy directly impact recurrence and survival outcomes. Currently, there is no standard for mesenteric lymphadenectomy, with a lymph node yield of 12 acting as a surrogate quality marker. Our goal was to determine the safety and feasibility of indocyanine green (ICG) fluorescence imaging to demonstrate lymphatic drainage in colon cancer in a dose-escalation study. A prospective pilot study of colon cancer patients undergoing curative laparoscopic resection was performed. At surgery, peritumoural subserosal ICG injection was done to demonstrate lymphatic drainage of the tumour. A specialized fluorescence system excited the ICG and assessed lymphatics in real time. The primary outcome was the feasibility of ICG fluorescent lymphangiography for lymphatic drainage in colon cancer. Secondary outcomes were the optimal protocol for dose, injection site, and ICG lymphatic mapping timing. Ten consecutive patients were evaluated (six males, mean age 69.5years). In all, lymphatic channels were seen around the tumour to a varying extent. Eight (80%) had drainage to the sentinel node. In all cases where the lymphatic map was seen, there was no further spread 10 min after injection. In 2 patients (20%), additional lymph nodes located outside of the proposed resection margins were demonstrated. In both cases the resection was extended to include the nodes and in both patients these nodes were positive on histopathology. Factors contributing to reduced lymphatic visualization were inadequate ICG concentrations, excess India ink blocking drainage, and inflammation from tattoo placement. ICG can be safely injected into the peritumoural subserosal and demonstrate lymphatic drainage in colon cancer. This proof of concept and proposed standards for the procedure can lead to future studies to optimize the application of image-guided precision surgery in colon cancer. Furthermore, this technique may be of value in indicating the need for more extended lymphadenectomy.

The lymphatic map of the lung

The lymphatic map of the lung

肺のリンパ経路―非小細胞性肺癌N2群の層別化―

肺のリンパ経路―非小細胞性肺癌N2群の層別化―

Cross-Reactivity of Filariais ICT Cards in Areas of Contrasting Endemicity of Loa loa and Mansonella perstans in Cameroon: Implications for Shrinking of the Lymphatic Filariasis Map in the Central African Region.

BackgroundImmunochromatographic card test (ICT) is a tool to map the distribution of Wuchereria bancrofti. In areas highly endemic for loaisis in DRC and Cameroon, a relationship has been envisaged between high L. loa microfilaria (Mf) loads and ICT positivity. However, similar associations have not been demonstrated from other areas with contrasting levels of L. loa endemicity. This study investigated the cross-reactivity of ICT when mapping lymphatic filariasis (LF) in areas with contrasting endemicity levels of loiasis and mansonellosis in Cameroon.Methodology/Principal FindingsA cross-sectional study to assess the prevalence and intensity of W. bancrofti, L. loa and M. perstans was carried out in 42 villages across three regions (East, North-west and South-west) of the Cameroon rainforest domain. Diurnal blood was collected from participants for the detection of circulating filarial antigen (CFA) by ICT and assessment of Mf using a thick blood smear. Clinical manifestations of LF were also assessed. ICT positives and patients clinically diagnosed with lymphoedema were further subjected to night blood collection for the detection of W. bancrofti Mf. Overall, 2190 individuals took part in the study. Overall, 24 individuals residing in 14 communities were tested positive by ICT, with prevalence rates ranging from 0% in the South-west to 2.1% in the North-west. Lymphoedema were diagnosed in 20 individuals with the majority of cases found in the North-west (11/20), and none of them were tested positive by ICT. No Mf of W. bancrofti were found in the night blood of any individual with a positive ICT result or clinical lymphoedema. Positive ICT results were strongly associated with high L. loa Mf intensity with 21 subjects having more than 8,000 L. loa Mf ml/blood (Odds ratio = 15.4; 95%CI: 6.1–39.0; p < 0.001). Similarly, a strong positive association (Spearman’s rho = 0.900; p = 0.037) was observed between the prevalence of L. loa and ICT positivity by area: a rate of 1% or more of positive ICT results was found only in areas with an L. loa Mf prevalence above 15%. In contrast, there was no association between ICT positivity and M. perstans prevalence (Spearman’s rho = - 0.200; p = 0.747) and Mf density (Odds ratio = 1.8; 95%CI: 0.8–4.2; p = 0.192).Conclusions/SignificanceThis study has confirmed the strong association between the ICT positivity and L. loa intensity (Mf/ml of blood) at the individual level. Furthermore, the study has demonstrated that ICT positivity is strongly associated with high L. loa prevalence. These results suggest that the main confounding factor for positive ICT test card results are high levels of L. loa. The findings may indicate that W. bancrofti is much less prevalent in the Central African region where L. loa is highly endemic than previously assumed and accurate re-mapping of the region would be very useful for shrinking of the map of LF distribution.

Shrinking the Lymphatic Filariasis Map of Ethiopia: Reassessing the Population at Risk through Nationwide Mapping.

BackgroundMapping of lymphatic filariasis (LF) is essential for the delineation of endemic implementation units and determining the population at risk that will be targeted for mass drug administration (MDA). Prior to the current study, only 116 of the 832 woredas (districts) in Ethiopia had been mapped for LF. The aim of this study was to perform a nationwide mapping exercise to determine the number of people that should be targeted for MDA in 2016 when national coverage was anticipated.Methodology/Principal FindingA two-stage cluster purposive sampling was used to conduct a community-based cross-sectional survey for an integrated mapping of LF and podoconiosis, in seven regional states and two city administrations. Two communities in each woreda were purposely selected using the World Health Organization (WHO) mapping strategy for LF based on sampling 100 individuals per community and two purposely selected communities per woreda. Overall, 130 166 people were examined in 1315 communities in 658 woredas. In total, 140 people were found to be positive for circulating LF antigen by immunochromatographic card test (ICT) in 89 communities. Based on WHO guidelines, 75 of the 658 woredas surveyed in the nine regions were found to be endemic for LF with a 2016 projected population of 9 267 410 residing in areas of active disease transmission. Combining these results with other data it is estimated that 11 580 010 people in 112 woredas will be exposed to infection in 2016.ConclusionsWe have conducted nationwide mapping of LF in Ethiopia and demonstrated that the number of people living in LF endemic areas is 60% lower than current estimates. We also showed that integrated mapping of multiple NTDs is feasible and cost effective and if properly planned, can be quickly achieved at national scale.

75. Endoscopic sentinel node biopsy and axillary dissection for early breast cancer can be navigated by the fusion image of 3D-CT lymphography and SPECT-CT

75. Endoscopic sentinel node biopsy and axillary dissection for early breast cancer can be navigated by the fusion image of 3D-CT lymphography and SPECT-CT

74. GIST may have a higher incidence of second primary cancers which negatively impact upon survival

74. GIST may have a higher incidence of second primary cancers which negatively impact upon survival

O1-7-6 - Endoscopic Sentinel Node Biopsy Can Be Navigated by the Fusion Image of 3D-Ct Lymphography and Spect-Ct

Background: 3D-CT mannmary lymphography (LG) can image the detail lymphatic map from the breast gland to the axillary nodes (AN) and can enable us to detect the precise sentinel node (SN) and to perform the endoscopic SN biopsy easily. It can also detect the second and the third SN on the lymphatic map. These node biopsy will contribute to omit AN dissection on the SN-positive patients. Now we try to overlay the fusion image of SPECT on the endoscopic view, and evaluate its real-time navigation of endoscopic surgery.Methods: 3D-CT LG was performed by the subcutaneous injection of 2 ml Iopamidol 300 above the tumor and near areola, and by taking CT images at 1 minute. They were reconstructed to produce a 3D image of lymph ducts and lymph nodes by the volume rendering method. SPECT was performed by injection of 99mTc phytate 74mBq and taking images after 2 hours. SN biopsy and AN dissection were performed by dye and RI method using endoscope with the optical trocar Visiport through only 1 cm long skin incision, and overlaying 3D-CT image on the endoscopic view with free-hand SPECT.Results: We have performed the endoscopic SN biopsy on 350 patients. The SN metastasis was found on 80 patients: single SN metastasis on 32, the second SN on 8, and the third SN on 7. The fusion image of 3D-CT LG and SPECT enable us to identify the anatomical position of SN on AN map by RI detector probe, and to introduce the endoscope by the overlay system. It also enable us to get the second SN easily. The axillary node metastasis was not observed on the patients without second SN metastasis. There was no false negative study. There is no local recurrence at 10 years after surgery.Discussions: The overlay of 3D-CT LG on the endoscopic view improve the identification rate of SN and the manipulation of the endoscopic surgery. We are developing these visual processing technique to apply the real-time navigation for the endoscopic partial mastectomy.

Shrinking the lymphatic filariasis map: update on diagnostic tools for mapping and transmission monitoring.

Lymphatic filariasis (LF), which is highly endemic in 73 countries worldwide, is targeted for elimination by 2020. The strategy for achieving this goal is based on 4 sequential programmatic steps: mapping, Mass drug administration (MDA) implementation, post-MDA surveillance and verification of LF elimination. All 4 stages of the implementation process are dependent on the availability of user friendly and highly sensitive rapid diagnostic tools. By the end of 2012, 59 countries had completed mapping for LF and Eritrea was the only country yet to start the process. Rolling out new diagnostic tools to facilitate the mapping process will enable an accelerated shrinking of the LF map to zero endemic countries by 2020. When the Global Programme to Eliminate Lymphatic Filariasis was launched in 2000, diagnostic tools for LF were limited to clinical examination, detection of microfilaria (MF) by microscopy in night blood samples and detection of antibodies to native-antigen preparations. There has been a significant improvement in the traditional LF diagnostic methods in recent years and some new tools are now available. This paper provides an update on the human diagnostic tests available for LF and their current applications as tools in mapping and transmission monitoring. The values of entomological indicators and parasite detection and speciation methods applied to vector populations are also discussed.

Classification TNM du cancer bronchique

The TNM classification has changed in 2009 on the basis of a new methodological approach. The various modifications and the new system are described with the different descriptors and symbols used. The new lymphatic nodes map is presented with the different stations and zones. The prognostic and operational roles are discussed as well as the potential improvements that might be proposed.

Lymphatic drainage of the external ear

Lymphoscintigraphy reveals inconsistencies in our knowledge of the lymphatic anatomy of the external ear. Fifteen external ears from 9 unembalmed human cadavers were studied. Six percent hydrogen peroxide was used to find the lymphatic vessels using a surgical microscope. They were injected with a radio-opaque mixture, dissected, photographed, and radiographed to demonstrate lymphatic vessels in the tissue. Final results were transferred to the computer for analysis. Four groups of lymph collecting vessels were found. The anterior branch, in all specimens, drained directly or indirectly (having merged with a vessel descending from the scalp) into the preauricular lymph nodes. The superior, middle, and inferior (lobule) branches drained to their multiple first tier lymph nodes. An accurate lymphatic map of the external ear is described to upgrade our anatomic knowledge. It will be of benefit for the clinical management of malignancies in this region.

Estudio del ganglio centinela en tumores de labio y cavidad oral

ObjectivesThis study shows the results obtained by the application of the sentinel node (SN) in oral and lip cancer and performs a lymphatic map of these tumours. Patients and methodWe prospectively studied 14 patients with lip and oral tumours, all of them N0. We injected colloidal particles of serum albumin labeled with Tc-99 peritumoraly and we located the SN intraoperatively. The SN was then sent for anatomopathological study. ResultsSentinel node was identified in all of the patients. In 11 of them the sentinel node was negative for metastases and correctly predicted the status of the neck. In 3 patients the sentinel node was the only node that contained metastases. There were no false negatives. The sensibility of the technique was 100%. ConclusionsThe results showed that this technique is a feasible method for tumours in these locations and can avoid neck dissections in N0 patients.

Lymph node micrometastasis and lymphatic mapping determined by reverse transcriptase-polymerase chain reaction in pN0 gastric carcinoma

Background. The purposes of this study were to examine lymph node micrometastasis (LMM) by reverse transcriptase-polymerase chain reaction (RT-PCR) method, and clarify the initial nodes involved by metastatic disease according to tumor location. Methods. We examined 312 lymph nodes obtained from 50 patients with node-negative gastric carcinoma. RT-PCR and immunohistochemistry were performed. The clinical characteristics of LMM were investigated, and the map of LMM was made according to tumor location. Results. The number of patients and LMM detected by RT-PCR was 14 and 17 and by immunohistochemistry was 7 and 8, respectively. RT-PCR was a more sensitive method than immunohistochemistry. LMM by RT-PCR correlated with depth of tumor invasion and lymphatic invasion. Regarding pT1 tumor, 9 patients with LMM had tumors that were of the macroscopically depressed type and 2 cm or more in diameter. According to the lymphatic map, right pericardial lymph nodes and lymph nodes along the lesser curvature were the initial nodes involved in the upper third of the stomach. Right pericardial lymph nodes, lymph nodes along the lesser curvature, and infrapyloric nodes were more important initial metastatic sites in the middle third of the stomach, and lymph nodes along the lesser curvature and infrapyloric nodes in the lower third. Conclusions. We demonstrated the relationship between LMM and clinicopathologic factors, especially in pT1 tumor. The mapping of LMM may prove useful for selecting the optimal treatment. (Surgery 2002;131:630-5.)