Long-term oncologic and functional outcome in pleomorphic adenomas of the submandibular gland

A review of submandibular gland extirpation in an Australian quaternary referral centre: aetiologies and trends over 35 years

BACKGROUND

Submandibular gland pathology is common but rarely reported. This study was performed to evaluate demographic, pathological, and survival outcomes associated with submandibular gland extirpation.

METHODS

Retrospective analysis of patients treated in a single quaternary-care institution between 1989 and 2022 was performed.

RESULTS

Four hundred and sixty patients underwent submandibular gland extirpation with a female preponderance (n = 271, 59%) and a mean age of 51 years. Older age was associated with increased risk of malignancy (P < 0.001). Submandibular calculus was the most common pathology, with gland extirpation for this indication decreasing over time (P = 0.005). Pleomorphic adenoma was the most common benign tumour (n = 96, 52.7% of total tumours), and adenoid cystic carcinoma was the most common malignant tumour (n = 25, 13.7% of total tumours).

CONCLUSIONS

Submandibular calculus remains the most common indication for submandibular gland extirpation, although the rate is decreasing over time. Pleomorphic adenoma continues to be the most common tumour of the submandibular gland, whilst adenoid cystic carcinoma is the most common malignant tumour. The incidence of benign versus malignant tumours has remained constant over the period of this study.

Comparisons between partial and total sialoadenectomy for benign submandibular gland tumors: A systematic review and meta-analysis

This study aimed to compare postoperative efficacy and functional outcomes between partial sialoadenectomy (PS) and total sialoadenectomy (TS) in patients with benign submandibular gland (SMG) tumors. We systematically searched PubMed, Web of Science, EmBase, Cochrane Library, China Biomedical Literature, and CNKI from inception to 2024, following PICOS criteria (Population: Adults with benign SMG tumors; Intervention: PS; Comparison: TS; Outcomes: Salivary function, neurological complications, recurrence, operative duration, dry mouth, infection/hematoma; Study design: RCTs/observational studies with ≥ 6-month follow-up). The protocol was prospectively registered (PROSPERO CRD42024595824). Risk ratios (RR) were calculated for dichotomous outcomes, and weighted mean differences (WMD) for continuous outcomes, using random-effects models. Heterogeneity was quantified by I2 statistics and Q tests. Sensitivity analyses included leave-one-out methods, and publication bias was assessed via funnel plots and Egger's test. The analysis of findings was guided by the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) framework to evaluate evidence certainty, while also considering the size of intervention effects in alignment with GRADE methodology. From 1014 screened studies, 7 studies (3 RCTs, 4 cohort studies) involving 399 patients (PS: n = 188; TS: n = 211) were included. PS demonstrated superior static saliva flow (WMD = 0.24, 95 %CI 0.13, 0.35)and reduced neurological complications (RR = 0.22, 95 %CI 0.10, 0.49), operative duration (WMD = -14.19, 95 %CI -23.4, -4.99), and dry mouth (RR = 0.12, 95 %CI 0.03, 0.49). However, there were no significant differences between the two groups in stimulated saliva flow (WMD = 0.01, 95 %CI -0.01, 0.04), tumor recurrence (RR = 3.23, 95 %CI 0.13, 77.99), postoperative infection (RR = 0.25, 95 %CI 0.03, 2.26), and postoperative hematoma (RR = 0.36, 95 %CI 0.08, 1.72). GRADE revealed moderate-certainty evidence for functional outcomesbut low/very low certainty for neurological complications, recurrence, operative duration, dry mouth, postoperative infection and hematoma. The current results demonstrate that partial sialoadenectomy offers significant advantages over traditional total sialoadenectomy.It is recommended that clinicians consider adopting new surgical procedures for the treatment of benign tumors of the submandibular gland in the future.

Extracapsular dissection versus total excision for benign submandibular gland tumors

INTRODUCTION

Benign submandibular gland tumors pose challenges in balancing treatment effectiveness and preserving gland function. This study aimed to compare gland-preserving surgery, extracapsular dissection (ECD), with total excision in managing these tumors, focusing on function preservation and recurrence rate.

METHODS

Fifty consecutive patients with treatment-naïve benign submandibular gland tumors were alternatively allocated to receive ECD (n = 25) or total excision (n = 25) without randomization procedures. Intraoperative findings, postsurgical complications, subjective satisfaction, and gland function were assessed. Follow-up data were collected for a median duration of 55 months (24-80 months) to monitor recurrences.

RESULTS

ECD demonstrated significant advantages, including shorter operation time, reduced bleeding, and preservation of the facial artery and vein (P < 0.05). Both groups exhibited acceptable postsurgical pain and taste sensations. Complications were minimal and similar between the two groups. ECD resulted in superior facial contour satisfaction (P = 0.030) and preserved gland function, as evidenced by salivary scintigraphy. No recurrences were observed in either group during the follow-up period.

CONCLUSIONS

ECD is a practical approach for benign submandibular gland tumors, offering favorable functional outcomes, reduced surgical morbidity, shorter operation times, and improved cosmetic results.

Functional gland-preserving surgery for submandibular gland pleomorphic adenoma

PURPOSE

Conventional surgery for submandibular gland tumour is total excision of the gland affected by the tumour. Gland-preserving surgery is commonly used for benign tumours arising in the parotid gland but not in the submandibular gland. This study evaluated long-term oncological and functional outcomes after gland-preserving surgery in patients with pleomorphic adenoma of the submandibular gland via the submental approach.

METHODS

This longitudinal study included 105 consecutive patients with submandibular gland pleomorphic adenoma who underwent the gland-preserving surgery combined with the en-bloc resection of tumours via the submental approach. Salivary scintigraphy was performed 6 months after surgery, and ultrasonography was regularly followed. Intraoperative findings, postoperative complications, cosmetic and salivary functions, and tumour recurrence were assessed in these patients.

RESULTS

Median tumour size and submental incision length were 2.0 and 3.3 cm, respectively. Median operation time and amount of blood loss were 25 min and 18.5 mL, respectively. None had marginal or lingual nerve paralysis and most patients were satisfied with incision scar and facial contour. The salivary function of the affected gland was equal to that of the unaffected gland. One patient (0.9%) had single nodular recurrence 54 months after surgery and others had no recurrence for follow-up of median 96 months.

CONCLUSIONS

Pleomorphic adenoma of the submandibular gland can be safely removed by the gland-preserving surgery via the submental approach which has operation time, cosmetic and functional benefits with compromising oncological outcomes.

Histopathological comparison of pleomorphic adenomas of the parotid and submandibular gland

OBJECTIVE

The aim of this study was to investigate and compare the histopathological findings in pleomorphic adenomas (PA) of the parotid and submandibular gland with emphasis on the histological subtype and capsular characteristics.

MATERIALS AND METHODS

The histopathological specimens of all patients with PAs of the parotid and submandibular gland between 2000 and 2020 were re-examined by an experienced head and neck pathologist. Patients without representative slides allowing evaluation of the whole periphery of the PA were excluded from our study sample.

RESULTS

Nine hundred and thirty-four patients formed our study sample (327 men, 607 women, male-to-female ratio: 0.53:1). Eight hundred and forty-four cases had a PA in the parotid gland and the remaining 90 in the submandibular gland. Our comparative analysis showed that submandibular PAs are characterized by the consistent presence of an intact anatomical capsule, infrequent occurrence of pseudopodia and satellite nodules, and a low proportion of the high-risk myxoid subtype.

CONCLUSION

Our study highlights significant differences between PAs of the parotid and submandibular glands in their histopathological characteristics. Their differences likely underlie the favorable surgical outcome observed in PAs of the submandibular glands and may explain the propensity of PAs of the parotid glands for local recurrences.

Resection of benign tumours of the submandibular gland with harmonic scalpel-assisted minimally extracapsular dissection

Objective

This study was performed to compare the oncologic and functional outcomes in patients with benign submandibular gland (SMG) tumours after harmonic scalpel-assisted minimally extracapsular dissection (HS-MECD) or total gland excision (TGE).

Methods

In total, 133 consecutive patients who were preoperatively diagnosed with benign SMG tumours (pleomorphic adenoma, Warthin’s tumour, basal cell adenoma, or lymphoepithelial cyst) from 2013 to 2016 were included in this two-centre retrospective study. Sixty-four patients underwent HS-MECD and 69 patients underwent TGE. All tumours were within 4 cm. Surgical variables, complications, functional outcomes, and recurrence rates were evaluated.

Results

The operation time, blood loss, drainage time and volume, and length of hospital stay were significantly lower in the HS-MECD than TGE group. HS-MECD reduced local pain and transient facial nerve paralysis outcomes. Incision scars and facial deformities were less visible according to the visual analogue scale. No significant differences were found in either unstimulated or stimulated whole saliva at 1 month postoperatively, whilst higher unstimulated levels were detected in the HS-MECD group at 6 months. The recurrence rate was similar between the two groups.

Conclusion

For benign SMG tumours of <4 cm, HS-MECD represents a less invasive technique than TGE and affords patients increased postoperative functionality.