Sentinel Lymph Node Evaluation in Early-Stage Vulvar Cancer.

OPINION STATEMENT: Sentinel lymph node mapping (SLNM) and dissection (SLND) should be used as an alternative to full inguinofemoral lymph node dissection (IFLND) in select patients with early-stage vulvar cancer. IFLND is associated with high postoperative complications such as wound breakdown, lymphedema, lymphocyst formation, and infection. SLND in select patients offers a safe, effective, and less morbid alternative. Candidates for SLND include patients with a unifocal vulvar tumor less than four centimeters, clinically negative lymph nodes, and no prior inguinofemoral surgeries. SLND should ideally be performed by a high-volume SLN surgeon. Most commonly, SLND is performed using both radiocolloid lymphoscintigraphy (e.g., Technetium-99) and a visual tracer such as blue dye; however, near infrared imaging with indocyanine green injection is becoming more widely adopted. Further prospective studies are needed to examine the safety and efficacy of various techniques for SLND. SLND has been demonstrated to be cost-effective, especially when including perioperative complications. Further studies are needed to demonstrate quality of life differences between IFLND and SLND.

Effect of inguinal lymph node dissection in lymph node negative patients with squamous cell carcinoma of the penis.

INTRODUCTION: The survival benefit of inguinal lymph node dissection (ILND) vs no ILND in patients with squamous cell carcinoma of the penis (SCCP) and the absence of lymph node invasion is unclear. We addressed this uncertainty within the Surveillance, Epidemiology and End Results (SEER 2000-2018) database. MATERIAL AND METHODS: We identified lymph node negative SCCP patients who either underwent ILND (pN0) or clinical examination only (cN0). We tested for the effect of ILND vs no ILND on cancer-specific mortality (CSM) in Kaplan-Meier plots, univariable and multivariable Cox regression analyses, in a pT stage-specific fashion, before and after 1:3 propensity score matching (PSM). Sensitivity analyses were conducted according to historical and contemporary treatment periods as well as geographic regions. RESULTS: Of 2520 SCCP patients, 369 (15%) underwent ILND (pN0) vs 2151 (85%) did not (cN0). The pN0 vs cN0 distribution according to pT stages was as follows: 80 (7%) vs 1092 (93%) in pT1b, and 289 (21%) vs 1059 (79%) in pT2-3. At 36 months, CSM-free survival in pT2-3 stage was 89% in ILND vs 74% in no ILND patients (multivariable hazard ratio: 0.42, CI 0.30-0.60, p < 0.001). This result was confirmed in sensitivity analyses, and after 1:3 PSM. The same analyses could not be completed in pT1b stage due to insufficient number of observations and events. CONCLUSIONS: In pT2-3 stage SCCP, a significantly lower CSM was recorded in lymph node negative patients treated with ILND than in their clinical lymph node negative counterparts who did not undergo ILND.

Inguinal lymph node metastases from rectal adenocarcinoma: a systematic review.

PURPOSE: Inguinal lymph nodes are a rare but recognised site of metastasis in rectal adenocarcinoma. No guideline or consensus exists for the management of such cases. This review aims to provide a contemporary and comprehensive analysis of the published literature to aid clinical decision-making. METHODS: Systematic searches were performed using the PubMed, Embase, MEDLINE and Scopus and Cochrane CENTRAL Library databases from inception till December 2022. All studies reporting on the presentation, prognosis or management of patients with inguinal lymph node metastases (ILNM) were included. Pooled proportion meta-analyses were completed when possible and descriptive synthesis was utilised for the remaining outcomes. The Joanna Briggs Institute tool for case series was used to assess the risk of bias. RESULTS: Nineteen studies were eligible for inclusion, encompassing 18 case series and one population-based study using national registry data. A total of 487 patients were included in the primary studies. The prevalence of ILNM in rectal cancer is 0.36%. ILNM are associated with very low rectal tumours with a mean distance from the anal verge of 1.1 cm (95% CI 0.92-1.27). Invasion of the dentate line was found in 76% of cases (95% CI 59-93). In patients with isolated inguinal lymph node metastases, modern chemoradiotherapy regimens in combination with surgical excision of inguinal nodes are associated with 5-year overall survival rates of 53-78%. CONCLUSION: In specific subsets of patients with ILNM, curative-intent treatment regimens are feasible, with oncological outcomes akin to those demonstrated in locally advanced rectal cancers.

Necessity of external iliac lymph nodes and inguinal nodes radiation in rectal cancer with anal canal involvement.

BACKGROUND AND PURPOSE: We aimed to explore the necessity of the external iliac lymph nodes (EIN) along with inguinal nodes (IN) region in clinical target volume (CTV) for rectal carcinomas covering the anal canal region. MATERIALS AND METHODS: This research premise enrolled 399 patients who had primary low rectal cancer detected below the peritoneal reflection via magnetic resonance imaging (MRI) and were treated with neoadjuvant radiotherapy (NRT), without elective EIN along with IN irradiation. We stratified the patients into two groups based on whether the lower edge of the rectal tumor extended to the anal canal (P group, n = 109) or not (Rb group, n = 290). Comparison of overall survival (OS), locoregional recurrence-free survival (LRFS), disease-free survival (DFS), as well as distant metastasis-free survival (DMFS) were performed via inverse probability of treatment weighting (IPTW) along with multivariable analyses. We compared the EIN and IN failure rates between the two groups via the Fisher and Gray's test. RESULTS: P group showed a similar adjusted proportion along with five-year cumulative rate of EIN failure compared with the Rb group. The adjusted proportion and five-year cumulative rate of IN failure in the P group was higher in comparison to the Rb group. There were no remarkable differences in the adjusted five-year OS, DFS, DMFS or LRFS between the two groups. Anal canal involvement (ACI) exhibited no effect on OS, LRFS, DFS, or DMFS. CONCLUSIONS: During NRT for rectal cancer with ACI, it may be possible to exclude the EIN and IN from the CTV.

Coverage probability planning for simultaneously integrated boosts of inguinal lymph nodes in vulvar cancer.

BACKGROUND AND PURPOSE: Strategies for minimizing irradiation of organs at risk (OARs) from pathological inguinal lymph node (PILN) boosting are needed to minimize the risk of morbidity. Coverage probability (CovP) is a conformal planning strategy for simultaneously integrated boost (SIB). Our aim was to investigate if SIB of PILN using CovP can be delivered safely in vulvar cancer. MATERIALS AND METHODS: Ten consecutive patients treated with definitive radiotherapy (RT) including SIB of PILN and with daily cone beam CT (CBCT) were included. Dose prescription was 51.2/32 fx to the elective target and 64 Gy/32 fx to the gross disease at the vulva and to positive lymph nodes (LN). PILN were contoured on both planning CT and MRI (GTV-N) and combined to form ITV-N. Each PILN GTV-N was contoured on every third CBCT, in total 11 CBCT for each patient. OARs were subcutaneous tissue (SC), inguinal vessels, skin rim, bowel, and body contour. Three plans were created for every patient: A) Standard CT-based planning; PTV-N based on GTV-NCT with a 10 mm isotropic margin. B) CT and MRI-based planning with smaller margins: PTV-N based on ITV-N with a 5 mm isotropic margin. C) CovP. The total delivered dose to GTV-Ns was estimated by accumulating dose across all fractions based on GTV-Ns contoured on CBCT. RESULTS: Thirty-five PILNs were boosted. There was no significant difference in accumulated GTV-N D98% between the three plans. CovP delivered a higher mean dose to the GTV-N D50% and D2% (p < 0.001). The planned mean doses to the OARs were reduced when applying CovP. CONCLUSIONS: SIB of PILN in vulvar cancer based on CovP and a 5 mm PTV margin does not compromise target coverage during RT and reduces the dose to normal tissues in the groin.

Dosimetric comparison of organs at risk using different contouring guidelines for definition of the clinical target volume in anal cancer.

BACKGROUND: There are different contouring guidelines for definition of the clinical target volume (CTV) for intensity-modulated radiation therapy (IMRT) of anal cancer (AC). We conducted a planning comparison study to evaluate and compare the dose to relevant organs at risk (OARs) while using different CTV definitions. METHODS: Twelve patients with a primary diagnosis of anal cancer, who were treated with primary chemoradiation (CRT), were selected. We generated four guideline-specific CTVs and subsequently planned target volumes (PTVs) on the planning CT scan of each patient. An IMRT plan for volumetric arc therapy (VMAT) was set up for each PTV. Dose parameters of the planned target volume (PTV) and OARs were evaluated and compared, too. RESULTS: The mean volume of the four PTVs ranged from 2138 cc to 2433 cc. The target volumes contoured by the authors based on the recommendations of each group were similar in the pelvis, while they differed significantly in the inguinal region. There were no significant differences between the four target volumes with regard to the dose parameters of the cranially located OARs. Conversely, some dose parameters concerning the genitals and the skin varied significantly among the different guidelines. CONCLUSION: The four contouring guidelines differ significantly concerning the inguinal region. In order to avoid inguinal recurrence and to protect relevant OARs, further investigations are needed to generate uniform standards for definition of the elective clinical target volume in the inguinal region.

Pathological and molecular diagnosis of bilateral inguinal lymph nodes metastases from low-grade endometrial adenocarcinoma: a case report with review of the literature.

BACKGROUND: Extra-abdominal metastases in low grade endometrial carcinoma are rare events. Inguinal lymphatic spread occurs usually in advanced disease and is associated with abdominal lymph nodes involvement. To our knowledge, isolated inguinal lymph node metastases in patients with early endometrial carcinoma have never been described thus far. CASE PRESENTATION: We present an uncommon case of inguinal lymph node metastasis in a 51-year old patient with early endometrial disease without other metastatic involvement. The metastatic loci were analyzed with the recently validated method of mitochondrial DNA sequencing to demonstrate clonality of the lesions. CONCLUSIONS: We describe the first case of inguinal metastasis from intramucous endometrial carcinoma; this case confirms the unpredictable spread of endometrial neoplasia and the importance of both patient's history and physical examination in good clinical practice.

Should epithelial ovarian carcinoma metastatic to the inguinal lymph nodes be assigned stage IVB?

OBJECTIVE: According to the revised FIGO staging system women with ovarian carcinoma and inguinal lymph node (LN) metastases, formerly stage III, are now considered stage IVB. In this study we compare their survival to that of women with stage III and stage IV disease. METHODS: Women diagnosed with epithelial ovarian carcinoma were drawn from the Surveillance, Epidemiology, and End Results database (2004-2013). Four groups were formed: group 1 (stage IV due to positive inguinal nodes), group 2 (stage III with positive para-aortic/pelvic nodes), group 3 (stage IV with positive distant nodes) and group 4 (stage IV with distant metastases). Overall (OS) and cancer-specific survival (CSS) rates were evaluated with the Kaplan-Meier method. The log-rank test and Cox-hazard models were employed for univariate and multivariate survival analysis. RESULTS: A total of 11,152 women were identified. Five-year OS for women in group 1 (n=151) was 46.3% compared to 44.9% for those in group 2 (n=4,403) (p=0.4), 32.9% in group 3 (n=642) (p<0.001) and 25.3% in group 4 (n=5,956) (p<0.001). After controlling for age, race and histology, group 1 had improved overall and cancer-specific mortality compared to groups 3 and 4 but not group 2. CONCLUSIONS: Ovarian cancer patients with stage IV ovarian cancer due solely to inguinal nodal metastases have similar survival as those with pelvic/para-aortic nodal involvement and improved survival compared to those harboring distant metastases. Our findings do not support the reclassification of these patients as stage IVB.

Comparing the safety and effectiveness of minimally invasive surgery and open inguinal lymph node dissection in penile cancer: A systematic review and meta-analysis.

OBJECTIVE: To compare the safety and effectiveness of minimally invasive surgery (MIS) with open inguinal lymph node dissection (O-ILND) in penile cancer. METHODS: We performed a systematic reviews and cumulative meta-analyses of primary results of interest according to PRISMA criteria, and quality assessment followed AMSTAR. The system searched five databases, including Zhiwang, Embase, PubMed, Cochrane Library and Web of Science. The search period ranged was from database creation until September 2023. The statistical analysis software used Stata16. RESULTS: A total of 16 studies, including 898 patients. Compared to O-ILND, MIS is superior in length of stay (WMD = -2.96, 95%CI [-4.38, -1.54], P < 0.05), drainage time (WMD = -3.24, 95%CI [-4.70, -1.78], P < 0.05) and estimated blood loss (WMD = -35.70, 95%CI [-46.27, -25.14], P < 0.05), while operation time, recurrence rate and 5-year overall survival rate are the same. The number of lymph nodes dissection between the two groups are not statistically significant. Subgroup analyses found that there are more lymph nodes dissection in robotic-assisted inguinal lymph nodes dissection (WMD = 0.50, 95%CI [0.20, 0.80], P < 0.05). The overall complication rate of MIS was lower (OR = 0.26, 95%CI [0.09, 0.70], P < 0.05). CONCLUSION: Minimally invasive inguinal lymph nodes dissection appears to be a better option for penile cancer cases. But more large samples and multicenter studies are needed to further confirm.

Is there a route for metachronous inguinal lymph node in colonic cancer? A case report.

As the inguinal lymph nodes do not serve as the primary route for the lymphatic drainage of the colon, inguinal metastasis from colorectal carcinomas is considered an unusual finding, especially in the 2nd year follow-up. A 76-year-old male patient, operated on for non-metastatic right colic adenocarcinoma, consulted 2 years after for a right inguinal swelling. A biopsy was performed. Unexpectedly, it showed an adenocarcinoma metastasis in favor of a colonic origin. There was no relapse of the disease. The pathological examination of the resected inguinal lymph node confirmed malignant cells from a colonic origin. As the positron emission tomography scan showed no other tumoral localizations, a multidisciplinary discussion ensued, culminating in the choice of chemotherapy for optimal pathological response. This case highlights the fact that colic drainage may encounter inguinal lymph nodes and thus inguinal groin metastasis could exceptionally have been seen in colonic carcinomas.

Management of Bulky Inguinal and Pelvic Lymph Nodes.

Penile cancer with bulky inguinal metastasis has a high probability of harboring pathologically involved lymph nodes best managed in a multidisciplinary care setting. Appropriate staging with cross-sectional imaging and fine-needle aspirate cytology of suspicious nodes guide decision-making for the use of platinum-based neoadjuvant chemotherapy followed by inguinal lymph node dissection. Surgical resection plays an important diagnostic, therapeutic, and guiding role in disease management. Patients with adverse pathologic features, especially those with extranodal disease extension, may derive additional benefit from adjuvant radiotherapy.

The role of preoperative ultrasound evaluation of inguinal lymph nodes in patients with vulvar malignancy.

OBJECTIVES: Inguinal lymphadenectomy in vulvar malignancies is associated with significant morbidity, especially in patients over 70 years old. Under certain conditions, surgical guidelines recommend biopsy and evaluation of the sentinel node in early vulvar cancer. The purpose of our study is to evaluate ultrasonography as a predictor of inguinal lymph node involvement. METHODS: A retrospective study was performed with 60 patients who had vulvar malignancies (92% of which were squamous cell carcinomas) and who were treated at our hospital between 2002 and 2012. The patients ranged in age from 35 to 89 years, with a median age of 76 years. In total, 118 groin scans were retrospectively evaluated for sonographic evidence of lymph node involvement (i.e., absence of fatty hilum, irregular shape, cortical region diameter and vascularization pattern). The results were then compared with histopathologically confirmed lymph node status. RESULTS: Histopathologically confirmed lymph node status was available for 107 of the inguinal nodes examined by ultrasound, and lymph node metastases were found in 38 (35.5%) cases. The presence or absence of inguinal lymph node metastases was correctly identified by sonography in 92 (86.0%) of the scanned areas. Sensitivity was 76.3%, specificity was 91.3%, and positive and negative predictive values were 82.9% and 87.5%, respectively. CONCLUSIONS: Ultrasonography of the inguinal lymph nodes showed a relatively high sensitivity and specificity for predicting inguinal tumor metastases. However, our results indicate that surgical lymph node staging is still needed to precisely determine inguinal lymph node status in vulvar cancer, especially because a missed lymph node-metastasis is often fatal.

Streptococcus suis contributes to inguinal lymph node lesions in piglets after highly pathogenic porcine reproductive and respiratory syndrome virus infection.

The swine pathogens porcine reproductive and respiratory syndrome virus (PRRSV) and Streptococcus suis have both been reported to cause damage to the immune organs. Inguinal lymph node (ILN) injury has been reported in PRRSV-infected pigs with secondary S. suis infection, but not much is known about the mechanism. In this study, secondary S. suis infection after highly pathogenic (HP)-PRRSV infection caused more severe clinical symptoms, mortality, and ILN lesions. Histopathological lesions were seen in ILNs with a marked decrease in lymphocyte numbers. Terminal deoxynucleotidyl transferase (TdT)-mediated de-oxyuridine triphosphate (dUTP)-biotin nick end-labeling (TUNEL) assays revealed that HP-PRRSV strain HuN4 alone induced ILN apoptosis, but dual-infection with S. suis strain BM0806 induced greater levels of apoptosis. Besides, we found that some HP-PRRSV-infected cells underwent apoptosis. Furthermore, anti-caspase-3 antibody staining confirmed that ILN apoptosis was mainly induced by a caspase-dependent pathway. Pyroptosis was also observed in HP-PRRSV-infected cells, and there was more pyroptosis in piglets infected with HP-PRRSV alone compared with those with secondary S. suis infection, and HP-PRRSV-infected cells underwent pyroptosis. Altogether, this is the first report to identify pyroptosis in ILNs and which signaling pathway is related to ILN apoptosis in single or dual-infected piglets. These results contribute to a better understanding of the pathogenic mechanisms during secondary S. suis infection.

The postnatal development of the compartments in human lymph nodes up to 15 years of age.

The postnatal development of normal human lymph nodes (LN) is largely unknown but is of relevance for intranodal desensitization and for comparison to lymphoma. Superficial inguinal lymphoid (LN) of 25 children (newborn up to 14 years) were studied by routine histology and immunohistology for T and B lymphocytes. The LN were obtained from the legal medicine department at necropsy. The cortex and medulla were identifiable in LN of children of less than 1 month of age. Later high endothelial venules as typical structures for the T cell area are present. Secondary follicles were obvious from 3 months of age onwards in lymph nodes of adolescents also the histology of the LN was similar to adults. The structural elements for an intranodal desensitization are given in human children. The normal development of LN structure is essential to identify pathology like lymphoma in children.

Synchronous ovarian and Bartholin gland carcinoma: Case report and review of literature.

To our knowledge, this is the first reported case of synchronous ovarian and vulva (Bartholin gland) cancer. A postmenopausal woman presented with a complex multiloculated left adnexal mass and 2-cm right Bartholin gland mass. CA 125 was 59 IU/mL. Computed tomography of chest, abdomen, and pelvis showed a very large (32 × 13.5 × 22.5 cm) complex mass arising from the pelvis and extending to the level of the T12/L1 disk space. A right Bartholin mass with suspicious right inguinal nodes was seen. Midline laparotomy, total abdominal hysterectomy, bilateral salpingo-oophrectomy, infracolic omentectomy, pelvic peritoneal biopsies, and peritoneal washings were carried out. Wide local excision of the right Bartholin gland mass was carried out in the same setting. Histopathology came back as Stage 2B left ovarian clear-cell carcinoma and synchronous right Bartholin gland adenoid cystic carcinoma with lymphovascular invasion, incompletely excised, staged at least FIGO Stage 1B. Following local multidisciplinary team discussion and positron emission tomography scan review, the local committee agreed to start three cycles of adjuvant chemotherapy then proceed with Bartholin gland scar re-excision and bilateral groin lymph node dissection. After the three cycles, the groin lymph nodes came back as metastatic adenocarcinoma with overall morphologic and immunohistochemical features consistent with metastatic ovarian clear-cell carcinoma. Postoperative adjuvant chemotherapy was given. Initial follow-up period over 9 months was uneventful.

Discussion on the necessity of bilateral inguinal lymphatic area irradiation for cervical cancer with invasion of the lower one-third of the vagina.

Context: According to the National Comprehensive Cancer Network guidelines for cervical cancer, patients with cervical cancer invading the lower one-third of the vagina require bilateral inguinal lymphatic area preventive irradiation. However, it is not clear whether they need preventive inguinal area irradiation. Aims: The aim of this study is to evaluate the necessity of bilateral inguinal lymphatic area irradiation for patients with cervical cancer with invasion of the lower one-third of the vagina. Settings and Design: Patients without inguinal lymph node metastasis were divided into preventive radiotherapy and nonpreventive radiotherapy groups. The occurrence of inguinal skin damage, lower extremity edema, and femoral head necrosis was observed during and after treatment. Methods and Material: In total, 184 patients with cervical cancer with invasion of the lower one-third of the vagina were selected. A trial and control method was used to select 180 patients without inguinal lymph node metastasis. Statistical Analysis: Comparison between groups was performed using a t test. Data were enumerated using frequency (percentage), and comparison between groups was performed using a Chi-square test. Results: Imaging examination revealed inguinal lymph node enlargement in 7.07% of patients, and only four cases (2.17%) were further confirmed by pathology. The inguinal lymph node metastasis rate in these patients was very low. The prophylactic irradiation group showed a high occurrence rate of side injury. In the follow-up of both groups, no recurrence was detected in the inguinal lymph nodes. Conclusions: Prophylactic irradiation of inguinal lymph nodes is not essential for patients without pathological metastasis.

Inguinal lymph node dissection in the era of minimally invasive surgical technology.

BACKGROUND: Inguinal lymph node dissection (ILND) is an essential step in both treatment and staging of several malignancies including penile and vulvar cancers. Various open, video endoscopic, and robotic-assisted techniques have been utilized so far. In this review, we aim to describe available minimally invasive surgical approaches for ILND, and review their outcomes and complications. METHODS: The PubMed, Wiley Online Library, and Science Direct databases were reviewed in February 2020 to find relevant studies published in English within 2000-2020. FINDINGS: There are different minimally invasive platforms available to accomplish dissection of inguinal nodes without jeopardizing oncological results while minimizing postoperative complications. Video Endoscopic Inguinal Lymphadenectomy and Robotic Video Endoscopic Inguinal Lymphadenectomy are safe and achieve the same nodal yield, a surrogate metric for oncological adequacy. When compared to open technique, Video Endoscopic Inguinal Lymphadenectomy and Robotic Video Endoscopic Inguinal Lymphadenectomy may offer faster postoperative recovery and fewer postoperative complications including wound dehiscence, necrosis, and infection. The relatively high rate and severity of postoperative complications hinders utilization of recommended ILND for oncologic indications. Minimally invasive approaches, using laparoscopic or robotic-assisted platforms, show some promise in reducing the morbidity of this procedure while achieving adequate short and intermediate term oncological outcomes.

Radiation therapy in the management of the inguinal region in penile cancer: What's the evidence?

Due to its rarity and lack of prospective studies, clinical evidence for the management of the inguinal lymphatic nodal basin with radiation therapy in penile cancer (PeCa) has been limited. In this report, we review the current literature and further investigated the landscape of radiation sensitivity in nodal metastases of PeCa utilizing our well-established genome-based radiosensitivity index (RSI) platform. We hypothesized that optimal therapeutic gain could be achieved in PeCa stratified by the combination of clinicopathological parameters, genomic heterogeneity, and RSI-based radiation dose prescription (RxRSI). Similar to primary PeCa lesions, we found that the majority of PeCa nodal metastases are genomically radioresistant with significant heterogeneity. RxRSI should be considered to inform and optimize the radiation therapy dose prescription to the individual tumor biology.

Kimura disease with Allergic Bronchopulmonary Aspergillosis: a case report.

BACKGROUND: Kimura disease (KD) is a rare chronic idiopathic condition of unknown etiology that is prevalent in Asian males. It often causes subcutaneous lumps and enlarged lymph nodes, especially in head and neck region. But KD is also a systemic disease that can involve multiple organs, such as the kidneys and skin. CASE PRESENTATION: We report a 62-year-old Chinese man who presented with paroxysmal cough, enlarged inguinal lymph nodes, recurrent skin itching, and elevated IgE antibodies specific to A. fumigatus. After a comprehensive review, the final diagnosis for this patient was KD with Allergic Bronchopulmonary Aspergillosis (ABPA). CONCLUSIONS: The age of onset and the location of the lump involved were not characteristic for the illness. This case report described the patient's diagnosis and treatment process. This case report serves to arouse the attention of multidisciplinary team to explore the potential relationship between KD and ABPA. It will contribute to preventing the misdiagnosis and missed diagnosis of KD.

Pathological Changes in the Lymphatic System of Patients with Secondary Lower Limb Lymphedema Based on Single Photon-Emission Computed Tomography/Computed Tomography/Lymphoscintigraphy Images.

Background: In patients with secondary upper limb lymphedema, positive correlations have been observed between the dermal back flow (DBF) type and visualization of lymph nodes around the clavicle, between the former and the lymph flow pathway type, and between the latter and the visualization of lymph nodes around the clavicle when using single photon-emission computed tomography/computed tomography/lymphoscintigraphy (SPECT-CT LSG). Methods and Results: We analyzed the associations between the visualization of inguinal lymph nodes, the lymph flow pathway type, and the DBF type using SPECT-CT LSG in 81 patients with unilateral secondary lower limb lymphedema by statistical analysis using Fisher's exact test. We revealed that the lymph flow pathways in the lower limb can be classified into nine types because the type in the lower leg is not always equal to the type in the thigh. Associations were observed between the visualization of inguinal lymph nodes and types of DBF (p < 0.01), between the types of lymph flow pathway in the thighs and visualization of the inguinal lymph nodes (p = 0.02), and between the lymph flow pathway types in the thighs and lower legs (p < 0.01). Conclusion: Detriment to the superficial lymph flow pathways in the lower limb appears to usually start from the proximal side, and deep pathways are considered to become dominant from a compensatory perspective as lymphedema severity increases.