Determining the number and distribution of intraparotid lymph nodes according to parotidectomy classification of European Salivary Gland Society: Cadaveric study

Surgery of major salivary gland cancers: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the role of surgery of the primary tumor site in the management of primary major salivary gland cancer.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group, which drafted a non-systematic narrative review of the literature published on Medline, and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group, according to the formal consensus method.

RESULTS

Treatment of salivary gland tumor is mainly surgical. The gold standard for parotid cancer is a total parotidectomy, to obtain clear margins and remove all intraparotid lymph nodes. For low-grade tumors, partial parotidectomy with wide excision of the tumor is acceptable in the case of postoperative diagnosis on definitive histology. In the event of positive margins on definitive analysis, revision surgery should be assessed for feasibility, and performed if possible.

CONCLUSION

Treatment of primary major salivary gland cancer is based on surgery with clear resection margins, as far away as possible from the tumor. The type of surgery depends on tumor location, pathologic type and extension.

Neck management in metastatic cutaneous squamous cell carcinoma of the head and neck

Objective

Optimal neck management remains unclear in head and neck cutaneous squamous cell carcinoma (HNcSCC) with parotid metastasis. Our goal was to compare the impact of different cervical treatments on HNcSCC with parotid metastasis.

Methods

Patients were retrospectively included. The primary outcome variables were regional control (RC) and disease-specific survival (DSS). The impacts of observation, elective neck irradiation (ENI), and elective neck dissection (END) were analyzed using the Cox model and presented as hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

In total, 268 patients were enrolled. In the Cox model for RC, compared with ENI, observation was associated with a significantly higher risk of regional recurrence (p = 0.001, HR = 2.50, 95%CI = 1.45-4.30). However, END showed a comparable influence on regional recurrence (p = 0.246, HR = 0.70, 95%CI = 0.38-1.28). In the Cox model for DSS, END demonstrated a similar HR of 0.62 (95%CI = 0.30-1.26) compared to ENI (p = 0.184). However, patients who underwent observation were associated with an additional nearly twofold risk of cancer-related mortality (HR = 2.85, 95%CI = 1.55-5.23). Subgroup analysis showed that ENI predicted comparable RC (p = 0.389) and DSS (p = 0.346) in patients with one or two metastatic parotid lymph nodes, but worse RC (p = 0.007) and DSS (p = 0.024) in patients with more than three positive lymph nodes.

Conclusion

In HNcSCC with parotid metastasis, elective treatment of neck lymph nodes with END or ENI should always be performed.

Topography and probability diagram of cervical and intra-parotid lymph node metastasis in parotid gland cancer

In parotid gland cancer (PGC), cervical lymph node metastasis (LNM) and intra-parotid LNM are known as significant indicators of poor prognosis. However, the topography of LNM in the affected parotid gland and the lymphatic progression of PGC has never been explored in detail. This was a retrospective analysis of data from 423 patients with previously untreated primary PGC (2005 to 2020), excluding patients with squamous cell carcinoma, lymphoma or metastatic disease in the parotid gland. The pattern of LNM was analyzed by neck sub-level and parotid sub-site. Using the conditional probability of neck level involvement, a probability diagram was plotted on several thresholds to visualize the sequential progression of LNM in PGC. The pattern of LNM progression was found to be similar between low- and high-grade pathology, but the incidence differed significantly (8.0% vs. 45.4%). Intra-parotid LNs and level IIa LNs were the most common sites (57.3% and 61.0%) of LNM in PGC, followed by level III (31.7%), Ib (25.6%), IV (22.0%), IIb (20.7%) and Va (20.7%) LNM. In intra-parotid LNs, the incidence of LNM in the deep parotid LNs was relatively low (9.4%); most intra-parotid LNMs were observed in the superficial parotid (90.6%) and peri-tumoral (in contact with the tumor) (31.3%) LNs. LNM to levels Ia, Vb and contra-lateral LNM occurred only in the very late stage. Our results provide detailed information about LNM progression in PGC at the sub-level and can help clinicians decide the treatment extent, including surgery or radiation.

Elective parotidectomy and neck dissection are not beneficial in cutaneous squamous cell carcinoma of the head

OBJECTIVE

Cutaneous Squamous Cell Carcinoma (cSCC), a tumor with a significantly increasing incidence, is mostly diagnosed in the head region, where tumors have a worse prognosis and a higher risk of metastases. The presence of metastases reduces specific five-year survival from 99% to 50%. As the risk of occult metastases does not exceed 10%, elective dissection of the tributary parotid and neck lymph nodes is not recommended.

METHODS

We retrospectively analyzed a group of 12 patients with cSCC of the head after elective dissections of regional (parotid and cervical) nodes by means of superficial parotidectomy and selective neck dissection.

RESULTS

We diagnosed occult metastases neither in the cervical nor parotid nodes in any patient. None were diagnosed as a regional recurrence during the follow-up period.

CONCLUCION

Our negative opinion on elective parotidectomy and neck dissection in cSCC of the head is in agreement with the majority of published studies. These elective procedures are not indicated even for tumors showing the presence of known (clinical and histological) risk factors for lymphogenic spread, as their positive predictive value is too low. Elective parotidectomy is individually considered as safe deep surgical margin. If elective parotidectomy is planned it should include only the superficial lobe. Completion parotidectomy and elective neck dissection are done in rare cases of histologically confirmed parotid metastasis in the parotid specimen. Preoperatively diagnosed parotid metastases without neck involvement are sent for total parotidectomy and elective selective neck dissection. Cases of clinically evident neck metastasis with no parotid involvement, are referred for comprehensive neck dissection and elective superficial parotidectomy. The treatment of concurrent parotid and cervical metastases includes total conservative parotidectomy and comprehensive neck dissection.

LEVEL OF EVIDENCE

How common is the problem? Step 4 (Case-series) Is this diagnostic or monitoring test accurate? (Diagnosis) Step 4 (poor or non-independent reference standard) What will happen if we do not add a therapy? (Prognosis) Step 4 (Case-series) Does this intervention help? (Treatment Benefits) Step 4 (Case-series) What are the COMMON harms? (Treatment Harms) Step 4 (Case-series) What are the RARE harms? (Treatment Harms) Step 4 (Case-series) Is this (early detection) test worthwhile? (Screening) Step 4 (Case-series).

Lymph node surgery for salivary gland cancer: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the indications for neck dissection in the management of parotid, submandibular or minor salivary gland cancers depending on the clinical situation: i.e., clinical lymph node involvement (cN+) or not (cN0); low or high risk of occult nodal metastasis; diagnosis of malignancy before, during or after surgery.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group which drafted a narrative review of the literature published on Medline and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group according to the formal consensus method.

RESULTS

In cN+ salivary gland cancer, ipsilateral neck dissection is recommended. In cN0 salivary gland cancer, ipsilateral neck dissection is recommended, except for tumors at low risk of occult nodal metastasis. If definitive pathology reveals a high risk of occult nodal involvement, additional neck treatment is recommended: ipsilateral neck dissection or elective nodal irradiation.

CONCLUSION

The rate of occult lymph node involvement, and therefore the indication for elective neck dissection, depends primarily on the pathologic grade of the salivary gland cancer.

Application of ultrasound in distinguishing the incipient microtumor from inherent lymph nodes of the parotid glands

BACKGROUND

Parotid microtumors (size ≤ 1 cm) pose a significant clinical challenge due to their malignant potential and risks associated with surgery. It is imperative to explore the diagnostic workflow that incorporates ultrasound (US) in order to make appropriate clinical decisions with minimal invasiveness.

METHODS

The patients receiving both US and ultrasound-guided fine needle aspiration (USFNA) for the parotid microtumors in a medical center were retrospectively recruited. The ultrasonic features, cytology of USFNA, and final surgical pathology were analyzed to differentiate the tumor origins and their malignant potential.

RESULTS

From August 2009 to March 2016, a total of 92 patients were enrolled in the study. The short axis, long-to-short axis ratio, and presence of an echogenic hilum were found to be significantly useful in distinguishing lymphoid tissue origin from salivary gland origin, which was confirmed by USFNA. An irregular border was predictive for malignant parotid microtumors from both origins. Intra-tumoral heterogeneity was also identified as a significant feature associated with malignant lymph nodes. USFNA was able to confirm all malignant lymph nodes, but it had a false negative rate of 8.5% in parotid microtumors of salivary gland origin. Based on the analysis of US and USFNA results, a diagnostic workflow for parotid microtumors was proposed.

CONCLUSION

US and USFNA can be helpful in classifying the origins of parotid microtumors. US-FNA carries the risk of producing false negative results specifically for microtumors originating from salivary glands, but not lymphoid tissue. The diagnostic workflow, which incorporates both US and USFNA, assists in determining the clinical decision for diagnosing and managing parotid microtumors.

Association between factor of parotid lymph node and prognosis in parotid cancer

INTRODUCTION

Survival significance of parotid lymph node (LN) factors in parotid cancer remains unclear, our goal was to assess the impact of number, size, and extranodal extension (ENE) of metastatic parotid LNs on prognosis in parotid cancer.

MATERIALS AND METHODS

Patients with surgically treated parotid cancer were retrospectively enrolled. Primary outcome variable was recurrence-free survival (RFS) and overall survival (OS). The hazard ratios (HRs) of main predictive variables including the number, size, and ENE of positive parotid LNs on RFS and OS were analyzed using Cox model. The secondary outcome variable was ENE of metastatic parotid LN, its association with clinicopathologic variables were evaluated using Chi-square test.

RESULTS

In total, 453 patients (186 male and 267 female) were included. The 10-year RFS and OS rates were 73% (95%CI: 69%-77%) and 61% (95%CI: 55%-67%), respectively. In Cox model, compared none parotid LN metastasis, one metastatic parotid LN did not offer additional compromise of RFS (p = 0.224) or OS (p = 0.135), but two or more positive LNs decreased the control of RFS (HR: 2.017; 95%CI: 1.378-4.632) and OS (HR: 2.173; 95%CI: 1.367-4.275). When accounting for the number of metastatic LNs, LN size or ENE was no longer related to RFS or OS. ENE of parotid LN tended to develop if there was presence of T3/4 stage, lymphovascular invasion, high histologic grade, N2/3 stage, and three or more positive parotid LNs.

CONCLUSION

Quantitative parotid LN burden but not ENE or LN size is an important determinant of survival in patients with parotid cancer.

Assessment of Parotid Gland Tumors by Means of Quantitative Multiparametric Ultrasound (mpUS)

OBJECTIVE

The preoperative diagnostical differentiation of parotid gland tumor (PGT) is not always simple due to several different entities. B-mode-ultrasound (US) remains the imaging modality of choice, while histopathology serves as the gold standard for finalizing the diagnosis. We aimed to evaluate the use of multiparametric US (mpUS) in the assessment of PGT.

METHODS

We included 97 PGTs from 96 patients. A standardized mpUS protocol using B-mode-US, shear-wave elastography (SWE), and standardized contrast-enhanced ultrasound (CEUS) was performed prior to surgical intervention. SWE was assessed by real-time measurement conducting a minimum of five measurements, while quantitative CEUS parameters were assessed with a post-processing perfusion software.

RESULTS

SWE allowed differentiation between benign PGT (Warthin's Tumor (WT) paired with lymph nodes (LN) and pleomorphic adenoma (PA)), and WT and LN were softer compared to PA. WT showed lower velocities than squamous cell carcinoma (SCC): the most common malignant PGT. CEUS parameters showed significant group differences between WT and PA, WT and malignant lesions, WT and SCC, WT paired with LN versus PA, and WT paired with LN versus SCC.

CONCLUSION

MpUS seems to be beneficial in the assessment of PGT characterization, with benign PGT appearing to be softer in SWE than tumors with malignant tendencies. The quantitative CEUS parameter shows higher perfusion in WT than in PA, and malignant PGTs are less vascularized than WTs.

Role of Intra-Parotid Lymph Node Metastasis in Primary Parotid Carcinoma

The parotid gland contains intra-glandular lymph nodes, the distribution of which is crucial for understanding the pathogenesis of intra-parotid lymph node metastases of parotid carcinoma and other head and neck carcinomas. Positive intra-parotid lymph node metastasis predicts the risk of positive cervical nodal metastasis. It is important to establish whether prophylactic neck dissection, including intra-parotid lymph nodes, contributes to treatment outcomes. The presence or absence of intra-parotid lymph nodes or metastasis-positive lymph nodes warrants further study. A preoperative diagnosis by imaging and fine-needle aspiration cytology of intra-parotid lymph nodes is difficult. Although intraoperative frozen section biopsy is performed during surgery, it is challenging to identify intra-parotid lymph nodes. The number of lymph nodes was the largest (47%) in the lower half of the superficial lobe, with 35% of nodes being concentrated in the inferior part of the cervicofacial branch, i.e., the lower pole of the parotid gland. Therefore, superficial parotidectomy and lower pole lobectomy need to be performed in cases in which a malignant tumor localizes to the superficial lobe or a lower pole. When intra-parotid lymph node metastases are detected during surgery, selective neck dissection (at least levels II and III) needs to be simultaneously performed.