Anatomic-histologic study of the floor of the mouth: the lingual lymph nodes

Predicting nodal metastasis progression of oral tongue cancer using a hidden Markov model in MRI

Objectives

The presence of occult nodal metastases in patients with oral tongue squamous cell carcinomas (OTSCCs) has implications for treatment. More than 30% of patients will have occult nodal metastases, yet a considerable number of patients undergo unnecessary invasive neck dissection to confirm nodal status. In this work, we propose a probabilistic model for lymphatic metastatic spread that can quantify the risk of microscopic involvement at the lymph node level (LNL) given the location of macroscopic metastases and the tumor stage using the MRI method.

Materials and methods

A total of 108 patients of OTSCCs were included in the study. A hidden Markov model (HMM) was used to compute the probabilities of transitions between states over time based on MRI. Learning of the transition probabilities was performed via Markov chain Monte Carlo sampling and was based on a dataset of OTSCC patients for whom involvement of individual LNLs was reported.

Results

Our model found that the most common involvement was that of level I and level II, corresponding to a high probability of 𝑝b1 = 0.39 ± 0.05, 𝑝b2 = 0.53 ± 0.09; lymph node level I had metastasis, and the probability of metastasis in lymph node II was high (93.79%); lymph node level II had metastasis, and the probability of metastasis in lymph node III was small (7.88%). Lymph nodes progress faster in the early stage and slower in the late stage.

Conclusion

An HMM can produce an algorithm that is able to predict nodal metastasis evolution in patients with OTSCCs by analyzing the macroscopic metastases observed in the upstream levels, and tumor category.

Lymphomas Affecting the Sublingual Glands: A Clinicopathological Study

BACKGROUND

Lymphomas affecting the sublingual glands are extremely rare and very few case reports are currently available. Therefore, the aim of the current study is to describe the clinicopathological features of a series of lymphomas involving the sublingual glands.

METHODS

Cases diagnosed in four pathology services were assessed and the formalin-fixed paraffin-embedded tissue blocks were retrieved for diagnosis confirmation. Clinical data were obtained from patients' medical files.

RESULTS

We obtained seven cases of lymphomas in the sublingual glands, representing two follicular lymphomas, two diffuse large B cell lymphomas not otherwise specified (DLBCL NOS), two extranodal marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphomas) and one mantle cell lymphoma (MCL). In all cases the tumor cells infiltrated the glandular parenchyma, although in two of them the neoplastic cells were located more superficially and permeated the glandular acini and ducts. Clinically, the tumors presented as asymptomatic nodules and two patients (affected by DLBCL NOS and MCL) died, while the other five patients remained alive at last follow-up.

CONCLUSION

Lymphomas affecting the sublingual glands are usually of the mature B cell lineage, often represent low-grade subtypes and may clinically resemble other more common lesions in the floor of the mouth like salivary gland tumors.

Application of near-infrared fluorescence imaging in lingual lymph node screening and drainage pattern observation for tongue cancer

Objective: Lingual lymph node (LLN) metastasis is regarded as an indicator of unfavorable prognosis and a crucial sign of the high degree of primary tumor aggressiveness. However, detecting LLN metastasis is an important but frequently overlooked aspect of diagnosis and surgical treatment planning. The study aims to identify LLNs by intraoperative near-infrared (NIR) fluorescence imaging with indocyanine green absorbed into human serum albumin (ICG: HSA) and describe the presence of lymphatic drainage channels from the floor of the mouth in patients with tongue carcinoma.

Materials and Methods: 21 patients diagnosed with cT1-T4 squamous cell carcinoma (SCC) of the tongue margin and scheduled to undergo tumor resection and unilateral neck dissection were enrolled. After exposing the neck, the patients were injected with 0.3 ml of ICG: HSA (500 μM) in three quadrants around the tumor, excluding the mucous membrane of the basal region cavity. Employing a near-infrared fluorescence imaging system, the fluorescence of levels I, II, III, and IV was measured during neck dissection.

Results: LLNs were detected in four patients and were identified as metastatic LLNs in all 21 patients. The near-infrared fluorescence imaging system showed the existence of lymphatic drainage channels in the floor of the mouth. In patients receiving peritumoral injection of ICG: HSA, the mean fluorescence intensity (MFI)of metastatic lymph nodes (LNs) (178.4 ± 64.39, mean ± SD) was higher than that in non-metastatic LNs (132.0 ± 76.5, mean ± SD) (p < 0.05).

Conclusion: NIR fluorescence imaging with ICG: HSA could be used for intraoperative identification of LLNs and assist in the determination of metastatic lymph nodes for tongue carcinoma patients. Additionally, this finding demonstrates the feasibility of near-infrared fluorescence imaging in defining lymphatic drainage channels in the head and neck.

A novel definition and treatment of hyperinflammation in COVID-19 based on purinergic signalling

Hyperinflammation plays an important role in severe and critical COVID-19. Using inconsistent criteria, many researchers define hyperinflammation as a form of very severe inflammation with cytokine storm. Therefore, COVID-19 patients are treated with anti-inflammatory drugs. These drugs appear to be less efficacious than expected and are sometimes accompanied by serious adverse effects. SARS-CoV-2 promotes cellular ATP release. Increased levels of extracellular ATP activate the purinergic receptors of the immune cells initiating the physiologic pro-inflammatory immune response. Persisting viral infection drives the ATP release even further leading to the activation of the P2X7 purinergic receptors (P2X7Rs) and a severe yet physiologic inflammation. Disease progression promotes prolonged vigorous activation of the P2X7R causing cell death and uncontrolled ATP release leading to cytokine storm and desensitisation of all other purinergic receptors of the immune cells. This results in immune paralysis with co-infections or secondary infections. We refer to this pathologic condition as hyperinflammation. The readily available and affordable P2X7R antagonist lidocaine can abrogate hyperinflammation and restore the normal immune function. The issue is that the half-maximal effective concentration for P2X7R inhibition of lidocaine is much higher than the maximal tolerable plasma concentration where adverse effects start to develop. To overcome this, we selectively inhibit the P2X7Rs of the immune cells of the lymphatic system inducing clonal expansion of Tregs in local lymph nodes. Subsequently, these Tregs migrate throughout the body exerting anti-inflammatory activities suppressing systemic and (distant) local hyperinflammation. We illustrate this with six critically ill COVID-19 patients treated with lidocaine.

Prognostic impact of lingual lymph node metastasis in patients with squamous cell carcinoma of the tongue: a retrospective study

Squamous cell carcinoma (SCC) of the tongue rarely metastasizes to the lingual lymph nodes (LLNs), which are inconstant nodes and often situated outside the areas of basic tongue tumor surgery. The current study evaluated the clinicopathological features and prognostic impact of LLN metastasis (LLNM), compared to that of cervical lymph node metastasis, in patients with tongue SCC. A total of 608 patients underwent radical surgery for tongue SCC at our department between January 2001 and December 2016. During neck dissection, we scrutinized and resected lateral LLNs, when present. Of the 128 patients with lymph node metastasis, 107 had cervical lymph node metastasis and 21 had both cervical lymph node metastasis and LLNM. Univariate analysis demonstrated that LLNM was significantly associated with the adverse features of cervical lymph node metastasis. The 5-year disease-specific survival (5y-DSS) was significantly lower in patients with LLNMs than in those without LLNMs (49.0% vs. 88.4%, P < 0.01). Moreover, Cox proportional hazards model analyses revealed that cervical lymph node metastasis at level IV or V and LLNM were independent prognostic factors for 5y-DSS. LLNM has a strong negative impact on survival in patients with tongue SCC. An advanced status of cervical lymph node metastasis may predict LLNM.

MR lymphography with superparamagnetic iron oxide for sentinel lymph node mapping of N0 early oral cancer: A pilot study

OBJECTIVES

The purpose of this pilot study was to evaluate the usefulness of magnetic resonance lymphography (MRL) with superparamagnetic iron oxide (SPIO) in sentinel lymph node (SLN) mapping of clinically N0 early oral cancer, and to conduct a comparative study of this MRL with CT lymphography (CTL).

METHODS

CTL and MRL were performed for SLN mapping before surgery for 20 patients with clinically N0 early oral cancer. The detection rate, number, and location of SLNs in CTL and MRL were evaluated. Furthermore, optimal scanning/imaging timing in MRL was examined.

RESULTS

SLNs were detected by CTL in 18 (90%) patients, and the total and mean number of SLN were 35 and 1.8, respectively. All SLNs could be detected 2 min and 3.5-5 min after contrast medium injection. In all patients, SLNs were detected by MRL at 10 min after SPIO injection, and the total and mean number of SLN was 53 and 2.7, respectively. MRL at 30 min after the injection showed additional 18 secondary lymph nodes.

CONCLUSION

MRL with SPIO is safe and useful imaging for the detection of SLNs in clinically N0 early oral cancer, and the optimal imaging timing is 10 min after SPIO injection.

Lingual Lymph Node Metastases as a Prognostic Factor in Oral Squamous Cell Carcinoma-A Retrospective Multicenter Study

Backgrounds and Objectives: The epidemiology and prognostic role of lingual lymph node (LLN) metastasis in patients with oral squamous cell carcinoma (OSCC) remain unclear. Here, we aimed to analyze the clinicopathological features, risk factors, and prognostic role of LLN metastasis in patients with OSCC. Materials and Methods: In total, 945 patients with OSCC were retrospectively analyzed. Clinicopathological features were compared between patients with and without LLN metastasis. The risk factors of LLN metastasis and its effects on survival outcomes were evaluated using multi-variate analysis. Results: LLN metastasis was noted in 67 patients (7.1%). Habitual alcohol consumption and clinical neck node metastasis were independent risk factors for LLN metastasis. LLN metastasis was an independent prognostic factor for disease-free and overall survival, although LLN dissection did not improve survival outcomes. Conclusion: LLN metastasis is an independent adverse prognostic factor. Further prospective studies are needed to fully assess the extent of LLN dissection required in OSCC patients.

Metastasis to the lateral lingual lymph node located behind the submandibular gland: A case of squamous cell carcinoma of the tongue

Inconsistency in the definition of LLNs may be a hurdle in ensuring the accuracy of the evidence. Refinements in the classification of LLNs, based on the fascial anatomy and lymphatic vessels, are warranted.

Regional metastasis to anatomies beyond traditional neck dissection boundaries: a multi-institutional analysis focused on unconventional metastases in oral cancer patients

Background

Regional metastasis sometimes occurs in anatomies that are not included in traditional neck dissections. The purpose of this study was to evaluate the treatment outcomes of squamous cell carcinoma of oral cavity (SCCOC) patients with unconventional metastatic lymph nodes (UMLNs) in sublingual, buccinator, and parotid anatomies.

Methods

This retrospective multi-institutional analysis of squamous cell carcinoma of oral cavity patients with unconventional metastatic lymph nodes was performed from January 2008 to December 2015. All the included patients received surgical treatment for unconventional metastatic lymph nodes. The end point of the study was to determine the factors influencing these patients’ survival and the corresponding solutions to improve survival. Pathological grade, contralateral metastasis, extranodal extension, and other factors were collected and analyzed by logistic regression and the Cox model.

Results

A total of 89 patients were identified. Among these patients, 25 (28.1%) received primary treatment, 28 (31.5%) received staged (therapeutic) neck dissections, and 36 (40.4%) had recurrent or residual diseases. Altogether, 45 patients (51%) had buccinator node metastases, 31 (35%) had sublingual metastases, 12 (14%) had parotid metastases, and 1 had both buccinator and parotid metastases. Regarding regional metastases, 31 patients (34.8%) had isolated unconventional metastatic lymph nodes. Adjuvant therapies were administered to 72 (80.9%) patients, 25 (28.1%) of whom were treated with radio-chemotherapies. The overall survival rate was 38.2%. Multivariate analysis found that the subsites of unconventional metastatic lymph nodes (P = 0.029), extranodal extension in both unconventional metastatic lymph nodes (P = 0.025) and cervical lymph nodes (P = 0.015), sites of primary or recurrent squamous cell carcinoma of oral cavity (P = 0.035), and types of neck dissections (P = 0.025) were significantly associated with overall survival.

Conclusions

Unconventional metastatic lymph nodes are uncommon, yet awareness of potential unconventional metastatic lymph nodes should be heightened. Early surgical interventions are warranted in patients with sublingual or buccinator metastases, while caution should be given to those with parotid metastases. Aggressive en bloc (in-continuity) resections may be mandatory in advanced oral cancer cases for close anatomic locations with possible buccal or sublingual metastases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-020-02057-6.

Lingual lymph nodes: Anatomy, clinical considerations, and oncological significance

Lingual lymph nodes are an inconstant group of in-transit nodes, which are located on the route of lymph drainage from the tongue mucosa to the regional nodes in neck levels I and II. There is growing academic data on the metastatic spread of oral cancer, particularly regarding the spreading of oral tongue squamous cell carcinoma to lingual nodes. These nodes are not currently included in diagnostic and treatment protocols for oral tongue cancer. Combined information on surgical anatomy, clinical observations, means of detection, and prognostic value is presented. Anatomically obtained incidence of lingual nodes ranges from 8.6% to 30.2%. Incidence of lingual lymph node metastasis ranges from 1.3% to 17.1%. It is clear that lymph nodes that bear intervening tissues from the floor of the mouth should be removed to improve loco-regional control. Extended resection volume, which is required for the surgical treatment of lingual node metastasis, cannot be implied to every tongue cancer patient. As these lesions significantly influence prognosis, special efforts of their detection must be made. Reasonably, every tongue cancer patient must be investigated for the existence of lingual lymph node metastasis. Lymphographic tracing methods, which are currently implied for sentinel lymph node biopsies, may improve the detection of lingual lymph nodes.

Sentinel lymph node mapping of clinically N0 early oral cancer: a diagnostic pitfall on CT lymphography

OBJECTIVE

The purpose of this study was to reevaluate preoperative computed tomography lymphography (CTL) and enhanced CT images during follow-up to clarify whether SLNs enhanced by CTL were identified accurately before primary surgery with sentinel lymph node biopsy (SLNB) for clinically N0 early oral cancer.

METHODS

Thirty two early oral cancer patients without cervical lymph node metastasis were enrolled in this study. To clarify whether SLNs enhanced by CTL were identified accurately before primary surgery with SLNB, we reevaluated preoperative CTL and enhanced CT images during follow-up in all patients.

RESULTS

SLNs were detected by CTL in 31 of 32 patients (96.9%). During follow-up after primary surgery with SLNB, 4 of 27 patients without SLN metastasis had occult neck metastasis. Of the 4 patients, only 1 patient with cancer of floor of the mouth had overlooking of SLN, and the overlooking rate of SLN was 3.1%. The overlooked small SLN (2.9 × 3.3 × 3.1 mm) was located at contralateral level IB. The CT numbers before, 2, 5, 10 min after iopamidol injection, were 33 HU, 37 HU, 62 HU, 52 HU, respectively. The CT numbers of overlooked SLN 5 and 10 min after the injection was higher than CT images scanned before the iopamidol injection.

CONCLUSIONS

The enhancement of SLNs in CTL images after iopamidol injection should be compared sufficiently with CT images before iopamidol injection to avoid overlooking of SLNs in N0 early oral cancer.

CT lymphography for sentinel lymph node mapping of clinically N0 early oral cancer

BACKGROUND

The objectives of this retrospective study were to evaluate the usefulness of computed tomography lymphography (CTL) and to clarify the optimal timing of CTL in sentinel lymph node (SLN) mapping of clinically N0 early oral cancer.

METHODS

Twenty patients with clinically N0 early oral cancer underwent CTL with a 128 multi-detector row CT scanner to detect SLN the day before resection of primary tumor and SLN biopsy with indocyanine green (ICG) fluorescence guidance. CT scanning was performed in the first 10 patients at 2, 5, and 10 min after submucosal injection of iopamidol and in the remaining 10 patients at 2, 3.5, 5, and 10 min after the injection of contrast medium. We evaluated the SLN detection rate at each scan timing and the number and location of SLNs. We evaluated whether CTL-enhanced SLNs could be identified intraoperatively as ICG fluorescent lymph nodes.

RESULTS

SLNs were detected by CTL in 19 of the 20 patients (95.0%), and the mean number of SLNs was 2 (range, 1-4). All SLNs were located on the ipsilateral side; 35 of 37 SLNs were located at level I and II, and 2 SLNs were lingual lymph nodes. All SLNs could be detected 2 min and 3.5-5 min after contrast medium injection, and CTL-enhanced SLNs could be identified intraoperatively as fluorescent lymph nodes.

CONCLUSIONS

CTL could facilitate the detection of SLNs in early oral cancer, and the optimal timing of CT scanning was at 2 and 5 min after injection of contrast medium.