[Clinicopathological characteristics of angioimmunoblastic T-cell lymphoma with B-cell proliferation or neoplasms].

Objective: To investigate the clinical, pathological and immunophenotypic features, and differential diagnosis of angioimmunoblastic T-cell lymphoma (AITL) with B-cell proliferation or neoplasms. Methods: Eight qualified cases were collected from the Department of Pathology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China from January 2019 to July 2023. One case was diagnosed with AITL and diffuse large B-cell lymphoma (DLBCL) and the other seven cases were diagnosed with AITL and B-cell proliferation. Clinical characteristics and pathological morphology were summarized. Immunohistochemical analysis, fluorescence in situ hybridization and gene rearrangement detection were performed. Results: The patients' average age was 58 years. Five of them were male. Biopsies of the enlarged cervical lymph nodes showed structural destruction and exhibited various histologic patterns. Some cases revealed Burkitt-like morphology, a moderate tumor volume and slightly irregular nuclei. Some cases showed prominent nucleoli. High endothelial venules and expanded follicular dendritic cells were detected. Tumor cells derived from T-follicular helper (TFH) cells were positive for two or more TFH biomarkers. Nodular or diffuse patchy proliferation of B cells was noted around the tumor tissue, which was initially considered as B-cell lymphoma. All of the 8 cases showed monoclonal rearrangements of the T-cell receptor genes while 5 of them also showed clonal rearrangements of the Ig genes. Seven of the 8 cases were subject to the detection of C-MYC gene breakage and were all negative. EBV-positive cells were seen in 6 cases. Neoplastic B cells were positive for C-MYC (>40%), while proliferative B cells were negative for C-MYC (<40%). Conclusions: The histological morphology of AITL with B-cell proliferation or lymphoma may be different from AITL. An integrated analysis, incorporating clinical, morphologic, immunophenotypic, and molecular assessment, helps reach an accurate diagnosis. This group of cases demonstrated the clinical and pathological characteristics of AITL accompanied by B-cell proliferation and B-cell lymphoma. The findings suggest that C-MYC maybe a feasible indicator for distinguishing B-cell proliferation from B-cell lymphoma, and provide a simple and feasible immunohistochemical marker for the diagnosis and research of composite lymphoma.

Prolonged water-only fasting in the management of low-grade follicular lymphoma: a case series.

BACKGROUND: Follicular lymphoma typically follows an indolent and relapsing course often requiring several treatment cycles to achieve remission. Some patients opt to use complementary and alternative therapies particularly when observation is a treatment option. CASE PRESENTATION: Here we present a case series of three patients, a 50-year-old, White, Hispanic female, 56-year-old, White, non-Hispanic male, and 49-year-old, White, non-Hispanic male, who elected to undergo one or more prolonged water-only fasting and refeeding interventions to manage low to intermediate grade follicular lymphoma. Fasting was well tolerated in each patient. Each patient also experienced a reduction in the size and avidity of hypermetabolic lymph nodes as independently determined by their respective oncologists. CONCLUSION: The reported cases demonstrate positive outcomes in low-grade follicular lymphoma coinciding with prolonged water-only fasting and exclusively whole-plant-food dietary interventions. These findings highlight the potential of such interventions and warrant further exploration through preliminary observational research.

[Analysis of risk factors and construction of nomogram model for local lymph node metastasis in salivary gland mucoepidermoid carcinoma].

Objective: To analyze the risk factors affecting regional lymph node metastasis in salivary gland mucoepidermoid carcinoma (MEC) and to establish a nomogram model for individually predicting lymph node metastasis in salivary gland MEC. Methods: The clinical data of 2 152 patients with salivary gland MEC from 1975 to 2020 were collected from the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute. The collected data were divided into training cohort (1 506 cases) and validation cohort (646 cases) according to the ratio of 7∶3. Single-factor regression and multi-factor logistic regression were used to screen factors related to local lymph node metastasis in salivary gland MEC, with constructing of a nomogram. Calibration curve, receiver operating characteristic (ROC) curve, area under the ROC curve (AUC) and decision curve analysis were used to evaluate model performance in the validation cohort and the total cohort. Statistical tests were performed using SPSS (26.0) and R (4.3.0) software. Results: Multivariate logistic regression results showed that M stage [OR(95%CI):12.360(3.295-46.365), P=0.014], pathological grade Ⅱ、Ⅲ、Ⅳ[OR(95%CI): 1.956(1.329-2.879), 9.654(6.309-14.772), 9.298(6.072-14.238), P<0.001], T staging T2, T3, T4[OR(95%CI): 1.706(0.932-3.124), 3.021(1.790-5.096), 3.311(1.925-5.695), P<0.001], and gender [OR(95%CI):0.759(0.593-0.972), P=0.029] were independent factors affecting local lymph node metastasis in salivary gland MEC. Through verification in the validation cohort and the total cohort, the AUC values were greater than 0.8, and the calibration curve was close to the perfect reference line, proving that the constructed nomogram model had good specificity and sensitivity for predicting local lymph node metastasis in salivary gland MEC. Conclusion: M stage, pathological grade, T stage, and gender are risk factors for predicting regional lymph node metastasis and the established-nomogram has good predictive performance for local lymph node metastasis in salivary gland MEC.

A study on the correlation of Doppler ultrasound in the diagnosis of cervical lymph nodes in patients with laryngeal and hypopharyngeal cancers: An observational study.

The objective was to assess the diagnostic efficacy of Doppler ultrasound in detecting cervical lymph nodes in patients diagnosed with laryngeal and hypopharyngeal cancers. Patients undergoing surgery for laryngeal and hypopharyngeal cancers in the Otolaryngology Department from January 2021 to January 2023 were included. Two groups, with equal numbers, underwent ultrasound examination and intensive CT examination in the experimental and control groups, respectively, along with routine cervical lymph node dissection. A resident with over 6 years of clinical experience in the otolaryngology department performed routine bilateral cervical lymph node palpation. Sensitivity, specificity, and validity were compared among different examination methods. The McNemar test assessed specificity and sensitivity between palpation, color Doppler ultrasonography, and enhanced CT, while the Kappa concordance test evaluated the concordance between the 2 examination methods. Data were statistically analyzed using SPSS 23.0. Palpation showed a diagnostic sensitivity (DS) of 52.83% and specificity of 91.11% for all patients with cervical lymph node metastasis. Ultrasonography demonstrated a DS of 77.78% and specificity of 81.82% in patients with cervical lymph node metastasis, while intensive CT had a DS of 75.86% and specificity of 60.00%. Statistical significance (P < .05) was observed in the sensitivity between palpation and ultrasonography, and between palpation and enhanced CT. The specificity between enhanced CT and ultrasonography (P = .021) and between palpation and enhanced CT scan (P = .003) both showed statistical significance (P < .05). Doppler ultrasound yields diagnostic results highly consistent with pathological diagnoses in patients with laryngeal and hypopharyngeal cancers. Utilizing Doppler ultrasound can enhance the accuracy of diagnosing these cancers, aiding physicians in devising more suitable treatment plans for patients.

Comparative analysis of F-18 FDG PET/CT images between scrub typhus and systemic lupus erythematosus.

This study evaluated the use of F-18 fluorodeoxyglucose (FDG) PET/CT imaging to differentiate between scrub typhus and systemic lupus erythematosus (SLE) in patients presenting with lymphadenopathy. We carried out a retrospective analysis of 18 scrub typhus patients and seven SLE patients, using various imaging parameters, including lymph node size, spleen and liver lengths, the distance between the two farthest lesions (Dmax), and assessments of glucose metabolism. On FDG PET images, we measured the maximum standardized uptake value (SUVmax) of the lymph nodes, spleen, and liver and the mean standardized uptake value (SUVmean) of the liver and spleen. The Dmax values of scrub typhus patients were significantly longer than those of SLE patients, indicating that lymphadenopathy is more generalized in the patients with scrub typhus. The SUVmax values for the lymph node, spleen, and liver were also higher in patients with scrub typhus, while the SUVmean of the liver and spleen did not differ between the two groups. This study is the first to compare FDG PET/CT images between these two conditions, suggesting the potential of this imaging modality to provide critical diagnostic distinctions.

Intrathoracic Lymph Node Microcalcifications are Associated With a High Prevalence of Malignancy and Anaplastic Lymphoma Kinase Rearrangement: The "Calce" Study.

BACKGROUND: Microcalcifications are acknowledged as a malignancy risk factor in multiple cancers. However, the prevalence and association of intrathoracic lymph node (ILN) calcifications with malignancy remain unexplored. METHODS: In this cross-sectional study, we enrolled patients with known/suspected malignancy and an indication for endosonography for diagnosis or ILN staging. We assessed the prevalence and pattern of calcified ILNs and the prevalence of malignancy in ILNs with and without calcifications. In addition, we evaluated the genomic profile and PD-L1 expression in lung cancer patients, stratifying them based on the presence or absence of ILN calcifications. RESULTS: A total of 571 ILNs were sampled in 352 patients. Calcifications were detected in 85 (24.1%) patients and in 94 (16.5%) ILNs, with microcalcifications (78/94, 83%) being the predominant type. Compared with ILNs without calcifications (214/477, 44.9%), the prevalence of malignancy was higher in ILNs with microcalcifications (73/78, 93.6%; P<0.0001) but not in those with macrocalcifications (7/16, 43.7%; P=0.93). In patients with lung cancer, the high prevalence of metastatic involvement in ILNs displaying microcalcifications was independent of lymph node size (< or >1 cm) and the clinical stage (advanced disease; cN2/N3 disease; cN0/N1 disease). The anaplastic lymphoma kinase (ALK) rearrangement was significantly more prevalent in patients with than in those without calcified ILNs (17.4% vs. 1.7%, P<0.001), and all of them exhibited microcalcifications. CONCLUSION: ILN microcalcifications are common in patients undergoing endosonography for suspected malignancy, and they are associated with a high prevalence of metastatic involvement and ALK rearrangement.

Delayed tumor-draining lymph node irradiation preserves the efficacy of combined radiotherapy and immune checkpoint blockade in models of metastatic disease.

Cancer resistance to immune checkpoint inhibitors motivated investigations into leveraging the immunostimulatory properties of radiotherapy to overcome immune evasion and to improve treatment response. However, clinical benefits of radiotherapy-immunotherapy combinations have been modest. Routine concomitant tumor-draining lymph node irradiation (DLN IR) might be the culprit. As crucial sites for generating anti-tumor immunity, DLNs are indispensable for the in situ vaccination effect of radiotherapy. Simultaneously, DLN sparing is often not feasible due to metastatic spread. Using murine models of metastatic disease in female mice, here we demonstrate that delayed (adjuvant), but not neoadjuvant, DLN IR overcomes the detrimental effect of concomitant DLN IR on the efficacy of radio-immunotherapy. Moreover, we identify IR-induced disruption of the CCR7-CCL19/CCL21 homing axis as a key mechanism for the detrimental effect of DLN IR. Our study proposes delayed DLN IR as a strategy to maximize the efficacy of radio-immunotherapy across different tumor types and disease stages.

High expression of PD-L1 on conventional dendritic cells in tumour-draining lymph nodes is associated with poor prognosis in oral cancer.

INTRODUCTION: Oral squamous cell carcinoma (OSCC), while common and with a favorable prognosis in early stages, presents a marked reduction in survival rate upon metastasis to lymph nodes. Early detection of lymph node metastasis via biomarkers could enhance the therapeutic strategy for OSCC. Here, we explored dendritic cells (DCs) and cytotoxic T-cells in tumour-draining lymph nodes (TDLNs) as potential biomarkers. METHOD: Dendritic cells and cytotoxic T-cells in 33 lymph nodes were analyzed with multi-parameter flow cytometry in TDLNs, regional non-TDLNs surgically excised from 12 OSCC patients, and compared to 9 lymph nodes from patients with benign conditions. RESULTS: Our results displayed a higher proportion of conventional cDC1s with immunosuppressive features in TDLN. Further, high PD-L1 expression on cDC1 in TDLNs was associated with metastasis and/or recurrent disease risk. Also, elevated levels of memory CD8+ T-cells and terminally exhausted PD-1+TCF-1-CD8+ T-cells were observed in TDLNs and non-TDLNs compared to healthy lymph nodes. CONCLUSIONS: We conclude that TDLNs contain cells that could trigger an anti-tumor adaptive response, as evidenced by activated cDC1s and progenitor-like TCF-1+ T-cells. The detection of high PDL1 expression on cDC1s was indicative of TDLN metastasis and an adverse prognosis, proposing that PD-L1 on dendritic cells in TDLN could serve as a predictive biomarker of OSCC patients with a worse prognosis.

Single-Cell RNA Sequencing Reveals Transcriptional Landscape of Neutrophils and Highlights the Role of TREM-1 in EAE.

BACKGROUND AND OBJECTIVES: Neutrophils, underestimated in multiple sclerosis (MS), are gaining increased attention for their significant functions in patients with MS and the experimental autoimmune encephalomyelitis (EAE) animal model. However, the precise role of neutrophils in cervical lymph nodes (CLNs), the primary CNS-draining lymph nodes where the autoimmune response is initiated during the progression of EAE, remains poorly understood. METHODS: Applying single-cell RNA sequencing (scRNA-seq), we constructed a comprehensive immune cell atlas of CLNs during development of EAE. Through this atlas, we concentrated on and uncovered the transcriptional landscape, phenotypic and functional heterogeneity of neutrophils, and their crosstalk with immune cells within CLNs in the neuroinflammatory processes in EAE. RESULTS: Notably, we observed a substantial increase in the neutrophil population in EAE mice, with a particular emphasis on the significant rise within the CLNs. Neutrophils in CLNs were categorized into 3 subtypes, and we explored the specific roles and developmental trajectories of each distinct neutrophil subtype. Neutrophils were found to engage in extensive interactions with other immune cells, playing crucial roles in T-cell activation. Moreover, our findings highlighted the strong migratory ability of neutrophils to CLNs, partly regulated by triggering the receptor expressed on myeloid cells 1 (TREM-1). Inhibiting TREM1 with LR12 prevents neutrophil migration both in vivo and in vitro. In addition, in patients with MS, we confirmed an increase in peripheral neutrophils with an upregulation of TREM-1. DISCUSSION: Our research provides a comprehensive and precise single-cell atlas of CLNs in EAE, highlighting the role of neutrophils in regulating the periphery immune response. In addition, TREM-1 emerged as an essential regulator of neutrophil migration to CLNs, holding promise as a potential therapeutic target in MS.

Prognostic Value of Preoperative N Subcategories in Patients with Stage IIIA N2 Non-Small Cell Lung Cancer.

Purpose To evaluate the preoperative risk factors in patients with pathologic IIIA N2 non-small cell lung cancer (NSCLC) who underwent upfront surgery and to evaluate the prognostic value of new N subcategories. Materials and Methods Patients with pathologic stage IIIA N2 NSCLC who underwent upfront surgery in a single tertiary center from January 2015 to April 2021 were retrospectively reviewed. Each patient's clinical N (cN) was assigned to one of six subcategories (cN0, cN1a, cN1b, cN2a1, cN2a2, and cN2b) based on recently proposed N descriptors. Cox regression analysis was used to identify the significant prognostic factors for recurrence-free survival (RFS) and overall survival (OS). Results A total of 366 patients (mean age ± SD, 62.0 years ± 10.1; 202 male patients [55%]) were analyzed. The recurrence rate was 55% (203 of 366 patients) over a median follow-up of 37.3 months. Multivariable analysis demonstrated that cN (hazard ratios [HRs] for cN1 and cN2b compared with cN0, 1.66 [95% CI: 1.11, 2.48] and 2.11 [95% CI: 1.32, 3.38], respectively) and maximum lymph node (LN) size at N1 station (≥12 mm; HR, 1.62 [95% CI: 1.15, 2.29]), in addition to clinical T category (HR, 1.51 [95% CI: 1.14, 1.99]), were independent prognostic factors for RFS. For OS, clinical N subcategories (cN1, cN2a2, and cN2b vs cN0; HRs, 1.91 [95% CI: 1.11, 3.27], 1.89 [95% CI: 1.13, 2.18], and 2.02 [95% CI: 1.07, 3.80], respectively) and LN size at N1 station (HR, 1.75 [95% CI: 1.12, 2.71]) were independent prognostic factors. For clinical N1, OS was further stratified according to LN size (log-rank test, P < .001). Conclusion Assessing the proposed N subcategories by reporting single versus multistation involvement of N2 disease and maximum size of metastatic LN, reflecting metastatic burden, at preoperative CT may offer useful prognostic information for planning optimal treatment strategies. Keywords: CT, Lung, Staging, Non-Small Cell Lung Cancer Supplemental material is available for this article. ©RSNA, 2024.

Study of Diagnostic Yield of Nucleic Acid Amplification Test among Tuberculous Cervical Lymphadenitis in Immunocompetent Patients.

BACKGROUND: The most common form of extrapulmonary tuberculosis (TB) is tuberculous lymphadenitis, which constitutes about 30-40% of all extrapulmonary TB cases. A new diagnostic method like the nucleic acid amplification test (NAAT) is a very sensitive and rapid test for diagnosing tuberculous cervical lymphadenopathy. It also detects rifampicin sensitivity among positive patients. OBJECTIVES: (1) To evaluate the diagnostic yield of TrueNAT for detecting Mycobacterium tuberculosis bacteria in the fine-needle aspirated samples of cervical lymph nodes compared with Ziehl-Neelsen (ZN) staining; (2) to evaluate the diagnostic yield of TrueNAT for diagnosis of tuberculosis through comparison with the cytology report of fine-needle aspiration (FNA) sample of cervical lymph node and with necrotic cervical lymph node on ultrasonography (USG) neck. MATERIALS AND METHODS: A total of 50 patients enrolled in this prospective study from January to December 2022. Demographic profile and clinical history were noted. Fine-needle aspirate samples were sent for TrueNAT assay, cytological examination, and ZN staining. USG neck was done for necrotic findings in the cervical lymph nodes. RESULTS: The TrueNAT positivity rate was 70%. TrueNAT sensitivity and specificity were assessed according to the cytology report, acid-fast bacilli (AFB) positivity on ZN stain, and the finding of necrosis in the cervical lymph node on the USG neck. The sensitivity and specificity of the TrueNAT assay were 80.49 and 77.78%, respectively, in accordance with necrosis on FNA cytology; 17.14 and 93.33%, respectively, in accordance with AFB positivity on ZN stain; and 74.29 and 33.33%, respectively, in accordance with lymph node necrosis on USG neck. CONCLUSION: The TrueNAT assay should be used as an adjunctive test in addition to the conventional cytological examination of the FNA sample of lymph nodes for the rapid diagnosis of tuberculosis. It also detects rifampicin resistance simultaneously.

Reevaluating Diagnosis of Sarcoidosis: Biopsy with Necrosis in Mycobacterial Endemic Areas.

BACKGROUND: Sarcoidosis is a multisystem inflammatory disease with a variable presentation. The most characteristic feature of sarcoidosis is nonnecrotizing granulomas. However, when sarcoidosis presents with rare organ involvement, and biopsy shows necrosis, the diagnosis becomes challenging. CASE PRESENTATION: Here, we present three cases of sarcoidosis with unusual organ involvement and biopsy findings of necrosis, leading to a delay in diagnosis and treatment. Case 1 was presented with lymphoreticular involvement within the intraparotid lymph node and genitourinary area. Biopsy from the epididymis showed necrosis, initially leading to treatment for tuberculosis (TB). Case 2 describes lymphoreticular involvement and cardiac symptoms. His cervical and bone marrow biopsies showed necrosis. Case 3's presentation was disseminated lymphadenopathy with hepatosplenomegaly, initially suspected as malignancy or TB. CONCLUSION: While biopsy plays a significant role in diagnosing sarcoidosis, the presence of necrosis alone should not lead to its exclusion.

An optical photothermal infrared investigation of lymph nodal metastases of oral squamous cell carcinoma.

In this study, optical photothermal infrared (O-PTIR) spectroscopy combined with machine learning algorithms were used to evaluate 46 tissue cores of surgically resected cervical lymph nodes, some of which harboured oral squamous cell carcinoma nodal metastasis. The ratios obtained between O-PTIR chemical images at 1252 cm-1 and 1285 cm-1 were able to reveal morphological details from tissue samples that are comparable to the information achieved by a pathologist's interpretation of optical microscopy of haematoxylin and eosin (H&E) stained samples. Additionally, when used as input data for a hybrid convolutional neural network (CNN) and random forest (RF) analyses, these yielded sensitivities, specificities and precision of 98.6 ± 0.3%, 92 ± 4% and 94 ± 5%, respectively, and an area under receiver operator characteristic (AUC) of 94 ± 2%. Our findings show the potential of O-PTIR technology as a tool to study cancer on tissue samples.

A Rare Case of Ileocecal Lymph Node Recurrence After Surgery in Siewert's Classification Type I Esophagogastric Junction Adenocarcinoma.

BACKGROUND Although recurrence after surgery for esophagogastric junction (EGJ) adenocarcinoma frequently develops in the mediastinal and para-aortic lymph nodes (LN), distant LN recurrence in the mesocolon is rare. We report a rare case of ileocecal LN metastasis in the ascending mesocolon after radical surgery for an EGJ adenocarcinoma. CASE REPORT We performed subtotal esophagectomy with mediastinal and para-gastric LN dissection in a patient with an advanced EGJ adenocarcinoma. Clinicopathologically, the patient was diagnosed with type I EGJ adenocarcinoma based on Siewert's classification (pathological T3N1M0). One year after surgery, computed tomography showed enlarged lymph nodes around the ileocolic artery, and further examination was performed. Although positron emission tomography-computed tomography showed that the lesion had moderate uptake of fluorodeoxyglucose, we did not find the reason for the enlarged lymph nodes. Finally, laparoscopic ileocecal resection was performed for diagnostic and therapeutic purposes. Clinicopathological tests revealed that the specimen was a moderately differentiated adenocarcinoma, which was strongly suspected to be a metastasis of the EGJ adenocarcinoma. CONCLUSIONS We encountered a rare case of EGJ adenocarcinoma that spread to the ileocecal LN in the ascending mesocolon. To the best of our knowledge, this is the first such report in the literature to date. Laparoscopic ileocecal resection for metastasis to the ascending mesocolon seems reasonable as a local control.

Comparison of D2 vs D3 lymph node dissection for RIght COloN cancer (RICON): study protocol for an international multicenter open-label randomized controlled trial.

BACKGROUND: Colon cancer is a global health concern, ranking fifth in both new diagnoses and deaths among tumors worldwide. Surgical intervention remains the primary treatment for localized cases, with a historical evolution marked by a focus on short-term outcomes. While Japan pioneered radical tumor removal with a systematic categorization of lymph nodes (D1, D2, D3), the dissemination of Japanese practices to the West was delayed until 90th of last century. Discrepancies between Japanese D3 dissection and the CME with CVL principle persist, with variations in longitudinal margins and recommended procedures. Non-randomized trials indicate the superiority of D3 over D2, but a consensus is lacking. METHODS: This prospective, international, multicenter, randomized controlled trial employs a two-arm, parallel-group, open-label design to rigorously compare the 5-year overall survival outcomes between D2 and D3 lymph node dissection in stage II-III right colon cancer. Building on prior studies, the trial aims to address existing knowledge gaps and provide a comprehensive evaluation of the outcomes associated with D3 dissection. The study population comprises patients with right colon cancer, ensuring a focused investigation into the specific context of this disease. The trial design emphasizes its global scope and collaboration across multiple centers, enhancing the generalizability of the findings. DISCUSSION: This study's primary objective is to elucidate the potential superiority in 5-year overall survival benefits of D3 lymph node dissection compared to the conventional D2 approach in patients with stage II-III right colon cancer. By examining this specific subset of patients, the research aims to contribute valuable insights into optimizing surgical strategies for improved long-term outcomes. The trial's international and multicenter nature enhances its applicability across diverse populations. The outcomes of this study may inform future guidelines and contribute to the ongoing discourse surrounding the standardization of colon cancer surgery, particularly in the context of right colon cancer. TRIAL REGISTRATION: ClinicalTrials.gov NCT03200834. Registered on June 27, 2017.

Modelling the lymphatic metastatic progression pathways of OPSCC from multi-institutional datasets.

The elective clinical target volume (CTV-N) in oropharyngeal squamous cell carcinoma (OPSCC) is currently based mostly on the prevalence of lymph node metastases in different lymph node levels (LNLs) for a given primary tumor location. We present a probabilistic model for ipsilateral lymphatic spread that can quantify the microscopic nodal involvement risk based on an individual patient's T-category and clinical involvement of LNLs at diagnosis. We extend a previously published hidden Markov model (HMM), which models the LNLs (I, II, III, IV, V, and VII) as hidden binary random variables (RVs). Each represents a patient's true state of lymphatic involvement. Clinical involvement at diagnosis represents the observed binary RVs linked to the true state via sensitivity and specificity. The primary tumor and the hidden RVs are connected in a graph. Each edge represents the conditional probability of metastatic spread per abstract time-step, given disease at the edge's starting node. To learn these probabilities, we draw Markov chain Monte Carlo samples from the likelihood of a dataset (686 OPSCC patients) from three institutions. We compute the model evidence using thermodynamic integration for different graphs to determine which describes the data best.The graph maximizing the model evidence connects the tumor to each LNL and the LNLs I through V in order. It predicts the risk of occult disease in level IV is below 5% if level III is clinically negative, and that the risk of occult disease in level V is below 5% except for advanced T-category (T3 and T4) patients with clinical involvement of levels II, III, and IV. The provided statistical model of nodal involvement in OPSCC patients trained on multi-institutional data may guide the design of clinical trials on volume-deescalated treatment of OPSCC and contribute to more personal guidelines on elective nodal treatment.