Lymphoma presenting as preauricular tumor in unilateral parotid gland agenesis: a case report and review of literature.

BACKGROUND: Parotid gland agenesis is a rare, congenital, usually asymptomatic disorder. Until now, only 24 cases with unilateral, incidentally found, parotid gland agenesis have been described. Here, we present the first reported case of an ipsilateral preauricular neoplasm in a patient with unilateral parotid gland agenesis. During surgery, the position of the greater auricular- and facial nerves was documented. Furthermore, we performed the first sialendoscopy for this rare disorder to assess the number of duct branches, which might be indicative of the abundance of parotid tissue. Moreover, we looked for sialendoscopic characteristic features that could aid in identifying these patients in the ambulatory setting. CASE PRESENTATION: A 50-year-old Greek man presented with a painless, slowly enlarging mass in the right parotid space. Magnetic resonance imaging revealed a complete absence of the right parotid gland without accessory parotid tissue. The right parotid gland was replaced by fatty tissue and the radiologist suggested a benign parotid tumor. Fine needle aspiration was indicative of a reactive lymph node. Sialendoscopy revealed only two branches within the right parotid duct. Surgical resection was performed through a conventional lateral parotidectomy. This revealed typical anatomic position of the greater auricular- and facial nerves despite the parotid tissue agenesis. Histopathology revealed a small lymphocytic lymphoma. CONCLUSIONS: Surgeons should feel confident to resect tumors of the parotid space in patients with parotid gland agenesis. Reduced branching observed during sialendoscopy might indicate parotid gland agenesis. Physicians should be even more cautious than usual with the watch and wait strategy in patients with tumors of parotid gland agenesis, since the probability of a tumor being a benign salivary gland tumor might be lower than usual.

Systematic review of the utilization of botulinum toxin in Mohs micrographic surgery.

The use of botulinum toxin for off-label indications has become more prevalent, but the specific benefits in Mohs micrographic surgery (MMS) have not yet been fully elucidated. A systematic review was performed of PubMed, Cochrane, EMBASE, and Scopus databases to identify all articles describing the use of botulinum toxin in MMS. Analysis was subdivided into scar minimization, parotid injury, and pain management. A total of nine articles were included. Scar minimization and treatment of parotid injury were the most reported uses. One case reported the use of botulinum toxin for pain management. Off label uses of botulinum toxin are being explored. Additional research is warranted to determine the efficacy and utility of botulinum toxin in MMS.

Basal cell adenoma and basal cell adenocarcinoma of the parotid gland: clinical findings and surgical outcomes in a single-institution study.

BACKGROUND: Basal cell adenoma (BCA) is a rare benign tumor within the salivary glands. Basal cell adenocarcinoma (BCAC), the malignant counterpart of BCA, is also an exceedingly rare tumor with very limited clinical studies conducted. This study aims to investigate the clinical characteristics, demographics, and surgical outcomes of patients diagnosed with BCA and BCAC within the parotid gland. METHODS: A retrospective analysis from May 2003 to August 2023 was performed for all patients undergoing parotidectomy for masses. Retrospective data on gender, age, tumor characteristics, and outcomes were collected. Surgical approaches, including negative margin attainment, capsule removal, and histological diagnosis, were also detailed. RESULTS: The study included 1268 patients who underwent parotidectomy, resulting in 81 cases of BCA and 7 cases of BCAC. BCA patients, with a mean age of 55.1 years, showed diverse age distribution and predominantly presented in the 50s. In BCAC cases, seven female patients exhibited a predominant location in the deep lobes. FNA revealed BCAC in three out of seven cases, and subsequent parotidectomy was performed, resulting in no observed recurrences or metastases. CONCLUSION: This study reports the largest number of BCA cases from a single institution and provides comprehensive insights into the demographics, tumor characteristics, and clinical outcomes of both BCA and BCAC. Although further research should be conducted, based on clinical follow-up results, appropriately including the capsule in the tumor excision indicates favorable outcomes, especially when the tumor size is not large.

Chinese surgical robot-assisted surgery for parotid tumor: a case report.

Robotic surgery is known as the "third technological revolution" in the field of surgery, and is an important milestone in the development of modern surgery. However, our country's innovative surgical robot industry is still in its early stages, and it is only being utilized in certain surgical fields. To explore the effectiveness of the application of domestic surgical robot in oral and maxillofacial surgery, the author successfully completed a case of benign parotid tumor resection with the assistance of a domestic autonomous robot. The operation was successful, facial nerve function was preserved, and postoperative wound healing was good.

Direct visualization of intraparotid facial nerve assisting in parotid tumor resection.

Precise recognition of the intraparotid facial nerve (IFN) is crucial during parotid tumor resection. We aimed to explore the application effect of direct visualization of the IFN in parotid tumor resection. Fifteen patients with parotid tumors were enrolled in this study and underwent specific radiological scanning in which the IFNs were displayed as high-intensity images. After image segmentation, IFN could be preoperatively directly visualized. Mixed reality combined with surgical navigation were applied to intraoperatively directly visualize the segmentation results as real-time three-dimensional holograms, guiding the surgeons in IFN dissection and tumor resection. Radiological visibility of the IFN, accuracy of image segmentation and postoperative facial nerve function were analyzed. The trunks of IFN were directly visible in radiological images for all patients. Of 37 landmark points on the IFN, 36 were accurately segmented. Four patients were classified as House-Brackmann Grade I postoperatively. Two patients with malignancies had postoperative long-standing facial paralysis. Direct visualization of IFN was a feasible novel method with high accuracy that could assist in recognition of IFN and therefore potentially improve the treatment outcome of parotid tumor resection.

Fenestration of the facial nerve by the stylomastoid artery.

BACKGROUND: Anatomic landmarks such as the tympanomastoid suture line, posterior belly of the digastric muscle, tragal pointer, and styloid process can assist the parotid surgeon in identifying and preserving the facial nerve. Vascular structures such as the posterior auricular artery and its branch, the stylomastoid artery, lay in close proximity to the facial nerve and have been proposed as landmarks for the identification of the facial nerve. In this case report, we describe an anatomic variation in which the stylomastoid artery has fenestrated the main trunk of the facial nerve, dividing it in two. METHODS: Two patients underwent parotidectomy (one for a pleomorphic adenoma, the second for a parotid cyst) through a standard anterograde approach with identification of the usual facial nerve landmarks. RESULTS: The appearance of the main trunk of the facial nerve was unusual in both patients due to its being fenestrated by the stylomastoid artery. The stylomastoid artery was divided, and the remainder of the facial nerve dissection was performed uneventfully with subsequent resection of the parotid mass in both patients. CONCLUSIONS: In rare instances, the stylomastoid artery can penetrate through the common trunk of the facial nerve. This is an important anatomic variant for the parotid surgeon to be aware of, as it can increase the difficulty of facial nerve dissection.

Mucosa-associated lymphoid tissue lymphoma at the parotid gland.

MALT (mucosa-associated lymphoid tissue) lymphomas are low-grade extra-nodal B-cell lymphomas that may involve various sites in the head and neck including the thyroid, salivary, and lacrimal glands. Development of MALT lymphoma in the head and neck is often associated with auto-immune diseases such as Sjögren syndrome or Hashimoto thyroiditis. Here, we report a case of a MALT lymphoma of the left buucal mucosa that likely arose in the parotid gland. The patient was successfully treated with surgical excision with chemotherapy and remained disease-free at the 10-year follow-up. Since it was rare in the head and neck region, we present this case.

Parotid Gland Metastases of Cutaneous Squamous Cell Carcinoma of the Head: Occult Metastases Occurrence and Their Late Manifestation.

Cutaneous squamous cell carcinomas (cSCC) are malignant tumours with excellent prognosis unless nodal metastases develop. The aim of our study is to determine the prognostic significance of the clinical stage of parotid gland metastases and the incidence of occult cervical lymph node involvement in cSCC of the head. Our retrospective analysis includes 39 patients with cSCC parotid gland metastases, 15 of whom had concurrent cervical node involvement. In 32 patients, the lymph nodes manifested at stage N3b. A total of 26 patients were treated with parotidectomy, 9 patients received radiotherapy alone, and 4 received symptomatic therapy. The surgical treatment included either total conservative (21 cases) or superficial parotidectomy (5 cases) and neck dissection (therapeutic neck dissections in 11 cases and elective in 14 cases). In all cases, surgery was performed with sufficient tumour-free resection margins. Adjuvant radiotherapy was administered postoperatively in 16 patients. Occult metastases were present in 21% of cases after an elective neck dissection, but not in any case in the deep lobe of the parotid gland. The five-year overall survival and recurrence-free interval were 52% and 55%, respectively. Patients with the cN3b stage and G3 histological grade tend to have a worse prognosis, but not at a statistically significant level. The prognosis was not worse in patients with concurrent parotid and cervical metastases compared to those with metastases limited to the parotid gland only. The addition of adjuvant irradiation, in comparison to a single modality surgical treatment, was the only statistically significant prognostic factor that reduced the risk of death from this diagnosis (p=0.013). The extent of parotidectomy (partial vs. total) had no impact on either the risk of recurrence or patient prognosis. The combination of surgery with irradiation provides the best results and should be applied to all patients who tolerate the treatment. A partial superficial parotidectomy should be sufficient, with a minimum risk of occult metastasis in the deep lobe. Conversely, the relatively high incidence of occult neck metastases indicates that patients could likely benefit from elective neck dissection.

Post-parotidectomy facial nerve rehabilitation outcomes: Comparison between benign and malignant neoplasms.

BACKGROUND: Facial nerve dysfunction can be a devastating trouble for post-parotidectomy patients. OBJECTIVE: To assess rehabilitation outcomes concerning patients with post-parotidectomy facial nerve dysfunction, comparing benign versus malignant neoplasms. METHODS: Prospective study enrolling adults who underwent parotidectomy with facial nerve sparing between 2016 and 2020. The Modified Sunnybrook System (mS-FGS) was used for facial assessments. Physiotherapy began on the first post-operative day with a tailored program of facial exercises based on Neuromuscular Retraining, to be performed at home 3 times/day. From the first outpatient consultation, Proprioceptive Neuromuscular Facilitation was added to the treatment of cases with moderate or severe facial dysfunctions. RESULTS: Benign and malignant groups had a statistically significant improvement in mS-FGS (p < 0.001 and p = 0.005, respectively). There was no significant difference between groups regarding treatment duration or number of physiotherapy sessions performed. The history of previous parotidectomy resulted in more severe initial dysfunctions and worse outcome. Age over 60 years and initially more severe dysfunctions impacted the outcome. CONCLUSION: Patients with benign and malignant parotid neoplasms had significant and equivalent improvement in postoperative facial dysfunction following an early tailored physiotherapy program, with no significant difference in the final facial score, treatment duration, or number of sessions required.

Elective nodal dissection for cN0 intermediate-grade parotid mucoepidermoid carcinoma: A NCDB study.

PURPOSE: To determine the occult nodal disease rate and whether elective regional lymph node dissection (RLND) confers any 10-year overall survival (OS) in cN0 intermediate-grade mucoepidermoid carcinoma (MEC) of the parotid gland. MATERIALS & METHODS: The National Cancer Database was reviewed from 2004 to 2016 on adults with cT1-4aN0M0 intermediate-grade parotid MEC undergoing resection with/without RLND. Comparisons between patients with and without RLND were made. Occult nodal rate and 10-year overall survival (OS) were determined. RESULTS: Out of 898 included patients with cN0 intermediate grade parotid MEC undergoing elective RLND, the occult nodal rate was 7.6%. This was significantly different from low-grade (3.9%) and high-grade (25.7%) cN0 disease. When stratified by pT-classification, marginal differences were identified between low-grade and intermediate-grade tumors, whereas high-grade tumors demonstrated increased occult nodal disease with low T-stage (pT1-pT2, 20.4% vs. 5.1%) and high T-stage (pT3-pT4a, 32.1% vs. 17.6%). Patients undergoing elective RLND were more often treated at an academic facility (53.8% vs. 41.2%), had higher pT3-pT4 tumors (19.2% vs. 10.4%), and more frequently underwent total/radical parotidectomy (46.0% vs. 29.9%) with adjuvant radiation therapy (53.8% vs. 41.0%) Cox-proportional hazard modeling did not identify RLND, regardless if stratified by nodal yield or pT-classification, nor nodal positivity as significant predictors of 10-year OS. CONCLUSIONS: The occult nodal disease in intermediate-grade parotid MEC is low and similar to low-grade. Elective RLND may have a limited impact on OS, though its effect on locoregional control remains unknown. LEVEL OF EVIDENCE: III.

[Postauricular hairline plus temporal approach gasless full-endoscopic parotidectomy for tumors in deep lobe of parotid gland: a 16-case report].

To investigate the safety and feasibility of gasless total endoscopic resection of deep lobe parotid gland tumors via a postauricular hairline plus temporal approach. The approach was designed as: a 4 to 5 cm main incision was designed at the postauricular hairline, and a 0.5 cm auxiliary incision was designed in the temporal hairline. The operating cavity was established with the assistance of a special retractor. "Anterograde" dissection of the facial nerve was performed throughout the procedure, along with partial or total gland removal of the tumor. All 16 operations were successfully completed without conversion to open surgery. During the operation, the trunk and branches of the facial nerve were completely preserved, the tumor was completely removed, and the incision healed. Six patients had mild facial paralysis after operation, and recovered completely after 3 to 6 months. There was no salivary fistula, Frey syndrome, infection, or other complications. The postoperative incision was concealed and the aesthetic effect was good. The postauricular hairline plus temporal approach gasless total endoscopic parotidectomy is safe and feasible. This technique can achieve the complete dissection of the total trunk to the branches of the facial nerve, and has good access to the tumors located in any part of the parotid gland region. On the basis of radical resection of the tumor, it achieves minimally invasive and aesthetic improvement.

The Volumetric Effect of Botulinum Toxin Type A Injection on the Parotid Gland: A Randomized Controlled Trial.

BACKGROUND: Botulinum neurotoxin type A (BTX-A) to the masseter muscle is a useful tool for the aesthetic narrowing of the width of the lower face. The administration of BTX-A to visible parotid glands is also effective to reduce lower facial width. However, no studies have quantitatively analyzed the effect of BTX-A on the parotid glands. METHODS: The purpose of this study was to confirm the impact of BTX-A injection on the parotid gland and to suggest the effective dosage of BTX-A in facial slimming. This study was conducted by selecting patients who desired facial slimming from among patients who required surgery for a facial bone fracture. Patients undergoing BTX-A injection were randomized to high-dose, low-dose, and placebo groups, and different doses of BTX-A for each group were injected into both parotid glands during facial bone surgery. RESULTS: A total of 30 patients were enrolled in this study. Ten patients in the high-dose group, eight in the low-dose group, and nine in the control group completed the clinical trial. There were significant changes in both the high- and low-dose groups compared with the control group ( P < 0.001, P < 0.001), and in interaction of time and group ( P < 0.001). Volume recovery after 3 months was found in 7.6% in the high-dose group and in 4.8% in the low-dose group. CONCLUSION: BTX-A injection into parotid glands can be an effective treatment option in managing salivary gland enlargement for lower face contouring. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

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.

Tumor localization is the important factor for recovery time of postoperative facial nerve paralysis in benign parotid surgery.

OBJECTIVE: Facial nerve paralysis is the most problematic complication of surgery for parotid tumors. This study aimed to examine the progress of recovery from postoperative transient facial nerve paralysis (POFNP). METHODS: Participants were 203 patients who developed POFNP after benign parotid surgery. A Kaplan-Meier showed the progress of recovery from paralysis. Factors involved in recovery were examined. For factors for which a significant difference was found, recovery from paralysis was examined over time. RESULTS: Rates of recovery from paralysis were as follows: 28.6% of patients at 1 month, 58.3% at 3 months, 85.9% at 6 months, and 95.1% at 12 months after surgery. Deep lobe tumors were shown to be significantly associated with delayed recovery from paralysis. The relationship between tumor location and the time of recovery from was that deep lobe tumors had a significantly worse recovery from paralysis at 4 and 5 months after surgery. CONCLUSION: Patients who develop POFNP must be informed about the progress of recovery and factors involved in recovery from paralysis. We believe that the results of the present study are a useful reference to that end.

The Role of Parotid Gland Invasion in Adenoid Cystic Carcinoma of the External Auditory Canal.

OBJECTIVE: This study aimed to investigate the significance of parotid gland invasion in predicting distant metastasis of adenoid cystic carcinoma in the external auditory canal. STUDY DESIGN: Single-institution retrospective cohort study. METHODS: A retrospective review of patients with adenoid cystic carcinoma of the external auditory canal who underwent surgery was performed. Information on patient demographics, parotid gland invasion, tumor stage, perineural invasion, lymphovascular invasion, and follow-up data were collected and analyzed. RESULTS: One hundred twenty-nine patients were identified for review. Parotid gland invasion was noted in 45 patients (34.9%). Parotid gland invasion was significantly associated with tumor stage, perineural invasion, distant metastasis, and postoperative adjuvant therapy. Distant metastasis was noted in 30 patients (23.3%). Multivariate Cox proportional hazards analysis identified parotid gland invasion as an independent risk factor for predicting distant metastasis. The 5-year distant metastasis-free survival rate was 83.6% for patients without parotid gland invasion and 61.8% for patients with parotid gland invasion (p = 0.010). CONCLUSIONS: The parotid gland invasion rate is relatively high in adenoid cystic carcinoma of the external auditory canal and is significantly related to tumor stage. Parotid gland invasion is associated with worse distant metastasis-free survival. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:419-425, 2024.

Comparison of conventional and endoscope-assisted partial clretain-->superficial parotidectomy for benign neoplasms of the parotid gland: a matched case-control study.

Long-term tumour recurrence rates and complications of endoscope-assisted partial superficial parotidectomy (PSP) are rarely reported compared to traditional open approaches. This retrospective study included 306 patients with superficial parotid benign neoplasms who were divided into an endoscopy group (endoscope-assisted PSP, n = 102) and a control group (conventional PSP, n = 204). There were no significant differences in clinical and pathological characteristics between the two groups, except age (P = 0.001). Three patients had confirmed recurrence during a mean follow-up duration of 125.1 months. Ten (9.8%) patients in the endoscopy group and 22 (10.8%) in the control group developed transient facial nerve palsy (P = 0.792), and recovered 6 months after the operation. Nine (8.8%) and 19 (9.3%) patients, respectively, suffered from Frey syndrome (P = 0.889). A sensory deficit of the auricle occurred in 24 (23.5%) and 57 (27.9%) patients respectively (P = 0.410). Patients in the endoscopy group were more satisfied with the postoperative scar than those in the control group (P < 0.001). This study demonstrated that the endoscope-assisted PSP can be curative, with better cosmetic outcomes than the conventional approach, and does not increase the incidence of postoperative complications or the local recurrence rate.

Mixed Reality Combined with Surgical Navigation in Resection of Micro- and Mini-Tumors of the Parotid Gland: A Pilot Study.

OBJECTIVE: This study aimed to evaluate the feasibility and outcomes of mixed reality combined with surgical navigation (MRSN) in the resection of parotid micro- and mini-tumors. METHODS: Eighteen patients who underwent parotid tumor resection between December 2020 and November 2022 were included. Six patients were enrolled in MRSN group, and the surgeons performed the surgery with the help of MRSN technology. The surgical procedures include virtual planning, data transfer between mixed reality and surgical navigation, tumor localization and resection assisted by surgical navigation under mixed reality environment. Twelve patients were enrolled in control group, and intraoperative tumor localization and resection were performed according to the experience of the surgeon. Total surgery time and intraoperative bleeding were recorded. Perioperative complications were recorded during follow-up. RESULTS: The mean surgery time of MRSN group (76.7 ± 14.0 min) and control group (65.4 ± 21.3 min) showed no significant difference (p = 0.220), so did the intraoperative bleeding of MRSN group (16.0 ± 8.0 mL) and control group (16.7 ± 6.6 mL) (p = 0.825). None of the patient in MRSN group underwent any complication, although one patient in control group suffered temporary facial paralysis. The mean deviation between the virtually marked and the intraoperative actual outermost point of tumor was 3.03 ± 0.83 mm. CONCLUSION: MRSN technology can realize real-time three-dimensional visualization of the tumor, and it has the potential of enhancing the safety and accuracy of resection of micro- and mini-tumors of parotid gland. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:1670-1678, 2024.