Reliability of large language models for advanced head and neck malignancies management: a comparison between ChatGPT 4 and Gemini Advanced.

PURPOSE: This study evaluates the efficacy of two advanced Large Language Models (LLMs), OpenAI's ChatGPT 4 and Google's Gemini Advanced, in providing treatment recommendations for head and neck oncology cases. The aim is to assess their utility in supporting multidisciplinary oncological evaluations and decision-making processes. METHODS: This comparative analysis examined the responses of ChatGPT 4 and Gemini Advanced to five hypothetical cases of head and neck cancer, each representing a different anatomical subsite. The responses were evaluated against the latest National Comprehensive Cancer Network (NCCN) guidelines by two blinded panels using the total disagreement score (TDS) and the artificial intelligence performance instrument (AIPI). Statistical assessments were performed using the Wilcoxon signed-rank test and the Friedman test. RESULTS: Both LLMs produced relevant treatment recommendations with ChatGPT 4 generally outperforming Gemini Advanced regarding adherence to guidelines and comprehensive treatment planning. ChatGPT 4 showed higher AIPI scores (median 3 [2-4]) compared to Gemini Advanced (median 2 [2-3]), indicating better overall performance. Notably, inconsistencies were observed in the management of induction chemotherapy and surgical decisions, such as neck dissection. CONCLUSIONS: While both LLMs demonstrated the potential to aid in the multidisciplinary management of head and neck oncology, discrepancies in certain critical areas highlight the need for further refinement. The study supports the growing role of AI in enhancing clinical decision-making but also emphasizes the necessity for continuous updates and validation against current clinical standards to integrate AI into healthcare practices fully.

Clinicopathological characteristics of four major histological types of high-grade parotid carcinoma.

OBJECTIVE: High-grade parotid carcinoma generally has a poor prognosis, and the histological type is mucoepidermoid carcinoma (MEC), salivary duct carcinoma (SDC), carcinoma ex pleomorphic adenoma (CEPA), or adenoid cystic carcinoma (AdCC) in the majority of cases. METHODS: During the 23-year period from September 1999 to December 2022, 250 patients with parotid carcinoma underwent initial treatment and had the histopathological type of their carcinoma. Retrospective study evaluated 111 MEC, SDC, CEPA, or AdCC cases among 134 patients with high-grade parotid carcinoma. We examined pathological and clinical features and prognosis, evaluated factors associated with recurrence, and performed immunohistological examinations. RESULTS: Pathological and clinical features and factors associated with recurrence were different for each histological type. The 10-year disease-free survival rates were as follows: MEC, 34.9%; SDC, 22.6%; CEPA, 47.1%; and AdCC, 56.3%. Human epidermal growth factor receptor type-2 and androgen receptor were positive in 48% and 56% of patients with SDC, respectively, 38% and 25% of those with CEPA. CONCLUSION: Each histological type has its own pathological and clinical features, recurrence types, and tumor activities, suggesting that differentiating between high-grade parotid carcinomas according to histological type will improve diagnosis, and thus prognosis.

Parotid carcinoma following chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids: a case report.

BACKGROUND: Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an inflammatory disorder with unclear causes. Paraneoplastic etiology may be a cause. We report a case of CLIPPERS with parotid carcinoma. CASE PRESENTATION: A 54-year-old man with a history of lymphoma was hospitalized with a pontocerebellar syndrome. Brain MRI revealed that the pons and cerebellum were "peppered" with punctate and curvilinear enhancement lesions that supported the diagnosis of CLIPPERS. The relapse of lymphoma was excluded by a further cerebellum biopsy revealing predominantly CD3+ T cells in white matter. The patient was relieved after pulse therapy with intravenous methylprednisolone and a large dose of corticosteroids, but he complained of a worsening gait problem when corticosteroids were tapered to a lower dose. Although the clinical symptoms gradually improved again by increasing the dosage of corticosteroids with Azathioprine, the patient still had a slight unsteady gait during follow-up. At the 7-month follow-up, a parotid mass was detected by MRI and was verified as carcinoma by biopsy. After resection of parotid carcinoma, the residual symptoms and previous MRI lesions disappeared, and no relapse occurred. CONCLUSIONS: CLIPPERS may not be a distinct nosologic entity but an overlapping diagnosis with other diseases. Some cases of CLIPPERS might be a subtype of paraneoplastic neurological syndromes (PNS) due to the similar mechanism of antibody-mediated encephalitis. Tumor screening and serum paraneoplastic autoantibody tests are recommended for patients with CLIPPERS, especially for those who relapse when corticosteroids treatment is stopped or tapered.

Impact of Changing Surgical Strategies on Clinical Outcomes in Patients with Parotid Carcinoma: A 53-Year Single-Institution Experience.

Background and Objectives: We investigated the clinical outcomes of patients who underwent surgery for parotid carcinoma in a single institution during a 53-year period. This study aimed to estimate the impact of changing the surgical approach to parotid carcinoma on clinical outcomes including the incidence rate of the facial nerve palsy. Materials and Methods: Sixty-seven patients with parotid carcinoma who underwent surgery between 1966 and 2018 were retrospectively reviewed. Group A consisted of 29 patients who underwent surgery from 1966 to 2002, and Group B consisted of 38 patients from 2002 to 2018. Treatment outcomes were estimated. Additionally, candidate prognostic factors of Group B, the current surgical approach group, were evaluated. Results: Partial parotidectomy and total parotidectomy were performed in 35 and 32 patients, respectively. Partial parotidectomy was performed in 4 patients in Group A and 31 patients in Group B, with a predominant increase in Group B. The facial nerve was preserved in 43 patients, among whom 8 in Group A (8/17; 47.1%) and 7 in Group B (7/26; 26.9%) had temporary postoperative facial nerve palsy. Postoperative radiotherapy was performed on 35 patients. The 5-year OS, DSS, and DFS rates for Group A were 77.1%, 79.9%, and 71.5%, respectively. The 5-year OS, DSS, and DFS rates for Group B were 77.1%, 77.1%, and 72.4%, respectively. Clinical T4 stage, clinical N+ stage, stage IV disease, and tumor invasion of the facial nerve were independent prognostic factors in Group B. Conclusions: The incidence of facial nerve palsy in the current surgical approach group decreased compared with that in the previous surgical approach group. The current surgical management and treatment policies for parotid carcinoma have led to improved outcomes.

Patterns of lymph node metastasis and the management of neck dissection for parotid carcinomas: a single-institute experience.

BACKGROUND: There is no consensus about the indications and range of neck dissection in patients who have parotid carcinoma, with elective neck dissection for cN0 disease being particularly controversial. METHODS: This study retrospectively reviewed 185 patients with newly diagnosed parotid carcinoma who were treated at our department between September 1999 and August 2018. RESULTS: 50 of the 185 patients had lymph node metastasis, including 7.7%, 12.2%, 36.0%, and 55.8% of patients with T1, T2, T3, and T4 disease, respectively. When classified by histological grade, 5.7% of patients with low/intermediate-grade disease had lymph node metastasis versus 55.0% of patients with high-grade disease. Multivariate analysis revealed that the histological grade and T classification were independent predictors of lymph node metastasis. Occult metastasis was found in 8 out of 73 clinically node negative patients undergoing neck dissection. The most common site of cervical metastasis was level 2, followed by the periparotid nodes, level 3, and level 4. CONCLUSION: Elective neck dissection may be most appropriate for parotid carcinoma patients with high grade disease and/or an advanced T classification. Because preoperative evaluation of the histological grade of parotid carcinoma has limited reliability, it is important to decide the indications and range of neck dissection from the results of frozen section biopsy.

Impact of payer status on survival in parotid malignancy.

OBJECTIVE: In the setting of current national healthcare reform, it becomes especially relevant to understand the current state of healthcare disparities with regards to insurance status. To determine the impact of payer status on survival in parotid malignancy, we utilized the National Cancer Database (NCDB). STUDY DESIGN: Retrospective database review. SETTING: National Cancer Database (2004-2012). SUBJECTS AND METHODS: The NCDB was queried for cases of primary malignancy of the parotid gland between 2004 and 2012. The impact of payer status on overall survival was evaluated, as well as the relationship of insurance status with patient and tumor variables. RESULTS: 15,815 cases met inclusion criteria. A majority had private insurance (47.8%), followed by Medicare (40.9%), Medicaid (5.0%), uninsured (3.2%) and other government sources (1.3%). Medicare patients had the lowest 5 and 10-year survival rates (50.7% (95% CI [49.3-52.1]) and 27.8% (95% CI [25.0-30.9]), respectively). On multivariable analysis, uninsured, Medicare, and Medicaid patients had worse overall survival than the privately insured (HR 1.42, 95% CI [1.17-1.74]; HR 1.29, 95% CI [1.17-1.42]; HR 1.36, 95% CI [1.13-1.62], respectively). Uninsured and Medicaid patients were more likely than the privately insured to present with advanced stage disease, nodal metastasis and longer times to treatment following diagnosis. CONCLUSION: In parotid malignancy, uninsured, Medicaid, and Medicare patients have worse survival outcomes compared to those with private insurance. Uninsured and Medicaid patients also present with more advanced stage disease and have increased wait times before definitive treatment is initiated.

Clinical characteristics of acinic cell carcinoma and secretory carcinoma of the parotid gland.

PURPOSE: Mammary analogue secretory carcinoma (SC) of the parotid gland is a relatively uncommon cancer associated with the ETV6-NTRK3 fusion product similar to breast cancer. The clinical characteristics and outcome of treatment were reviewed for patients with this tumor at our hospital. METHODS: In this retrospective case series, 24 patients with a diagnosis of acinic cell carcinoma (AcCC) of the parotid gland were classified as having either SC or AcCC based on analysis of the ETV6-NTRK3 fusion gene. These two groups were compared with respect to their clinical and imaging characteristics (MRI/US), cytologic findings, accuracy of fine-needle aspiration cytology and frozen section, treatment outcomes, and immunohistochemical findings. RESULTS: Based on re-classification by ETV6-NTRK3 fusion gene analysis, the diagnosis was SC in 14 patients and AcCC in 10 patients. The SC group had a significantly higher proportion of male patients and was also significantly younger than the AcCC group. Imaging studies revealed that SC was significantly more likely to show internal heterogeneity. Correct grading of both tumors was comparable by fine needle aspiration, with the rate being 60% for AcCC and 50% for SC. Diagnosis by frozen section biopsy diagnosis obtained the correct grade in 90% of the AcCC group and 93% of the SC group. CONCLUSIONS: In 24 patients previously diagnosed with AcCC, re-analysis of the ETV6-NTRK3 fusion product indicated that 14 patients actually had SC. Although AcCC and SC show similarities of their biological aggressiveness and prognosis, patients with SC were significantly more likely to be male and younger.

A clinicopathological study of parotid carcinoma: 18-year review of 171 patients at a single institution.

BACKGROUND: This study investigated the clinical outcomes of patients with parotid carcinoma at a single institution during an 18-year period, with the focus on diagnosis, treatment, and survival. METHODS: The subjects were 171 patients with parotid carcinoma treated at our department during the 18-year period from September 1999 to August 2017. There were 19 patients in stage I, 65 patients in stage II, 22 patients in stage III, and 65 patients in stage IV. The symptoms, preoperative diagnosis, node metastasis, survival rate, prognostic factors, and immunohistological findings were investigated. RESULTS: Preoperative diagnosis of the histological grade by fine-needle aspiration cytology was only possible in 34% of the patients, while the histological grade was correctly determined by frozen section biopsy in 72%. The overall frequency of lymph node metastasis was 29%, with 59% in patients with high-grade carcinoma and only 6% in those with low-/intermediate-grade tumors. The disease-specific 5-year survival rate was 100% for patients in stage I, 95.2% in stage II, 70.4% in stage III, and 45.1% in stage IV. Multivariate analysis showed that the pathological grade was the most important prognostic factor. Immunohistological investigation showed patients with HER-2 or androgen receptor-positive tumors had a significantly worse prognosis. CONCLUSIONS: Although a high-grade tumor is the most important prognostic factor, preoperative diagnosis of the grade was not always accurate. Since advanced cancer has a poor prognosis with a limited response to surgery and radiation therapy, development of new treatment strategies, such as molecular-targeting therapies directed against HER-2 and AR, is required.

Probability and pattern of occult cervical lymph node metastases in primary parotid carcinoma.

The present study was undertaken to evaluate real probability and pattern of cervical occult lymph node metastases (OLNM) in primary parotid carcinoma (PPC). We carried out a retrospective analysis of 66 patients treated in years 1992-2010 due to PPC, who underwent elective neck dissection (END). In search of risk factors for OLNM, we analysed the following parameters: age, sex, pT-Status, tumour size, skin invasion, facial nerve palsy, tumour fixation, extraparotid extension, localization, grade, histology, intra/periparotid LN metastases (IPLNM). OLNM was observed in 30.3% of patients. In a univariate analysis statistical significance was found for IPLNM, extraparotid extension and high risk histology. A multivariate analysis showed statistical significance only for the first variable. The most common location of cervical OLNM was level II (80%), then III (45%) and V (30%). In a compilation of our own material with data from the literature (5 series), we obtained a group of 80 patients with OLNM, selected out of 650 patients with cN0 (12.3%). The proportion of metastases to particular levels was the following: 69%-II, 22.5%-III, 20%-I,16%-V, 7.5%-IV. END should be carried out in case of all T3/T4a carcinomas with minimal range of levels II and III. Removal of levels Ib and Va is recommended as well. In the T1/T2 carcinomas with high grade/high risk histology, END should be performed including levels II and III.

Carcinoma of the salivary glands: guidelines and case report of sustained remission with docetaxel.

WHAT IS KNOWN AND OBJECTIVE: Salivary glands tumours are rare neoplasms for which there are few clinical trials. The most common malignant parotid tumour is the mucoepidermoid carcinoma. High-grade mucoepidermoid carcinomas are highly aggressive tumours. The initial therapy of localized disease is known, but when there is a recurrence, several options are possible and chemotherapy is generally reserved for palliative treatment. We comment on published guidelines and report a case of sustained remission with docetaxel. CASE SUMMARY: Our case concerns a 64-year-old woman with a high-grade mucoepidermoid carcinoma of the parotid gland with local recurrence treated with docetaxel 50 mg/m² every 15 days. After the sixth cycle, a complete remission was observed on CT-scan. The tolerability was excellent. After 2 years of docetaxel, the patient was still in complete remission. WHAT IS NEW AND CONCLUSION: Docetaxel is an active drug for the treatment of mucoepidermoid carcinoma of salivary glands. A prospective study should confirm these data.

Discriminating atypical parotid carcinoma and pleomorphic adenoma utilizing extracellular volume fraction and arterial enhancement fraction derived from contrast-enhanced CT imaging: A multicenter study.

OBJECTIVES: To investigate the added value of extracellular volume fraction (ECV) and arterial enhancement fraction (AEF) derived from enhanced CT to conventional image and clinical features for differentiating between pleomorphic adenoma (PA) and atypical parotid adenocarcinoma (PCA) pre-operation. METHODS: From January 2010 to October 2023, a total of 187 cases of parotid tumors were recruited, and divided into training cohort (102 PAs and 51 PCAs) and testing cohort (24 PAs and 10 atypical PCAs). Clinical and CT image features of tumor were assessed. Both enhanced CT-derived ECV and AEF were calculated. Univariate analysis identified variables with statistically significant differences between the two subgroups in the training cohort. Multivariate logistic regression analysis with the forward variable selection method was used to build four models (clinical model, clinical model+ECV, clinical model+AEF, and combined model). Diagnostic performances were evaluated using receiver operating characteristic (ROC) curve analyses. Delong's test compared model differences, and calibration curve and decision curve analysis (DCA) assessed calibration and clinical application. RESULTS: Age and boundary were chosen to build clinical model, and to construct its ROC curve. Amalgamating the clinical model, ECV, and AEF to establish a combined model demonstrated superior diagnostic effectiveness compared to the clinical model in both the training and test cohorts (AUC = 0.888, 0.867). There was a significant statistical difference between the combined model and the clinical model in the training cohort (p = 0.0145). CONCLUSIONS: ECV and AEF are helpful in differentiating PA and atypical PCA, and integrating clinical and CT image features can further improve the diagnostic performance.

Risk Factors for Poor Survival Outcomes in Parotid Metastatic Cutaneous Squamous Cell Carcinoma.

OBJECTIVE: We aimed to analyze risk factors associated with poor survival outcomes for metastatic cutaneous head-and-neck SCC to the parotid. METHODS: All patients undergoing surgery for metastatic cutaneous SCC to the parotid with curative intent between 2011 and 2018, were reviewed. Demographic and clinical characteristics were evaluated. Histopathological data including tumor size and histology, tumor grade, TNM stage, resection margins, lymphovascular invasion, and perineural invasion, were analyzed. Overall survival (OS), disease-specific survival (DSS), and freedom from locoregional recurrence (LRR) were assessed. RESULTS: Ninety patients were included (mean age, 77 years; 75 men [83.3%]). A total parotidectomy was performed in 48 patients (53.3%), and 42 (46.7%) underwent a superficial parotidectomy. Seventy patients (77.8%) underwent adjuvant RT. The median follow-up was 31 months (20-39 months). Tumor volume ≥ 50 cm3 and a shorter RT duration (<20 days) were associated with reduced OS (p = 0.002 and p = 0.01, p = 0.02 and p = 0.009, respectively), and DSS (p = 0.004 and p = 0.02, p = 0.04 and p = 0.02, respectively) on univariable and multivariable analysis, respectively. Only a shorter RT duration was associated with worse freedom from LRR on univariable and multivariable analysis, (p = 0.04 and p < 0.001, respectively). However, with death as a competing risk, a shorter duration of RT was not significantly associated with freedom from LRR. CONCLUSION: A shorter duration of adjuvant RT, and excised tumor volume ≥50 cm3 were predictive factors of reduced OS and DSS, and a shorter duration of RT was also associated with reduced freedom from LRR in patients with metastatic SCC to the parotid gland. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:1163-1168, 2023.

Successful Preoperative QUAD SHOT for Bulky Parotid Carcinoma: Potential Preoperative Ultra-Hypofractionated Radiotherapy for Conversion Surgery.

QUAD SHOT is an ultra-hypofractionated radiotherapy (RT) technique that prescribes 14.0-14.8 Gy over 2 days. Although this technique has already gained some status as an effective palliative treatment for inoperable head and neck cancer (HNC), its application in other situations has not been given much consideration. Herein, we report a case of a 62-year-old woman who received preoperative QUAD SHOT therapy for poorly differentiated parotid carcinoma. In this case, after two courses of QUAD SHOT plus a standard chemotherapy regimen with pembrolizumab, the patient's inoperable, bulky tumor shrank dramatically and became operable. Best of all, while adequate therapeutic effects were achieved, the patient's time commitment and physical exertion were limited. RT during this period consisted of only eight fractions over 4 days. According to previous reports, the response rate for QUAD SHOT is sufficiently high, and the rate of serious adverse events is quite low. This case asks the question of whether the indications for QUAD SHOT irradiation can be expanded as one of the preoperative interventions undertaken by HNC surgeons to achieve conversion surgery.

Management and outcome of adenoid cystic carcinoma of the major salivary glands: the 22-year experience of a single institution.

BACKGROUND: Prognostic factors and survival rate are difficult to determine for adenoid cystic carcinoma(AdCC) of salivary glands. AIMS/OBJECTIVES: To clarify the clinical characteristics of AdCC and examine factors associated with recurrence and prognosis by histopathological grade classification. MATERIALS AND METHODS: Twenty-five patients with AdCC of the parotid gland and 10 patients with AdCC of the submandibular gland were included. We classified AdCC histopathologically by the proportion of solid components. Clinical features, fine-needle aspiration cytology (FNAC), and patient outcomes were examined according to grade. Factors associated with local recurrence and distant metastases were examined. RESULTS: Age was significantly higher in the grade III group than in the grade I group. The grade III group had significantly higher proportions of patients with cN+, pN+, and perineural invasion. In FNAC, lower-grade groups showed higher rates of correct histopathological type. Five-year disease-specific survival and disease-free survival rates were significantly lower in the grade III than in the grade I. Distant metastases were more common among patients with high-stage and perineural invasion. CONCLUSIONS: Five-year survival is significantly worse in patients with grade III.

Intraductal Carcinoma of the Parotid Gland as a Rare Neoplasm: A Case Report and Literature Review.

Background: Intraductal carcinoma is a rare low grade neoplasm of salivary glands with an excellent prognosis. It most frequently occurs in the parotid gland. Ectopic localizations are quite rare. Methods: This case report describes a man in his 60's who was referred to ear, nose and throat outpatient department with 1-month history of painless swelling of the right parotid region. Results: Ultrasound-guided fine-needle aspiration unveiled a cytologic specimen judged as "suspicious for malignancy" and patient underwent a partial superficial parotidectomy. Immunohistochemistry confirmed diagnosis of intraductal carcinoma of right parotid gland. Conclusions: There are few reported cases concerning this clinical entity following thorough review of the literature and recent developments with reference to the contribution of cytology and histopathology will probably modify its classification and management.

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.

A retrospective study of parotid gland tumors at a single institution.

The aim of the present study was to analyze the clinical characteristics, surgical treatments and clinical outcome of patients with parotid gland tumors and to compare the results with those cited in the literature. A retrospective study was conducted in 140 patients (male, n=77; female, n=63) with parotid gland tumors who underwent parotidectomy at Hokuto Hospital Department of Otolaryngology-Head and Neck Surgery (Obihiro, Japan) between April 2007 and December 2021. Of the 140 patients enrolled, 118 (84.3%) patients had benign tumors, including 63 (45%) patients with pleomorphic adenomas and 43 (30.7%) patients with Warthin tumors, and 22 patients (15.7%) had parotid carcinoma. Comparison of the three groups of patients with parotid gland tumors indicated that pack years as an indicator of smoking status were significantly higher in patients with Warthin tumors than in those with parotid carcinomas (P=0.011) or pleomorphic adenoma (P<0.001). Fine-needle aspiration cytology (FNAC) was non-diagnostic for only 6 (4.3%) of 140 patients. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of FNAC by both conventional smear and liquid-based cytology (LBC) for parotid carcinomas were 70, 99, 93.3, 94.4 and 82.9%, respectively. Among the 22 patients with parotid carcinoma, extended total/total and superficial parotidectomy were performed in 10 (45%) and 11 (50%) cases, respectively. Total and selective neck dissection of the area from level II to I, II and III were performed in 6 (24%) and 7 (32%) patients, respectively. Postoperative radiotherapy (50 Gy) was performed in 15 (68%) patients. The overall survival (OS) and disease-free survival (DFS) rates at 5 years were 51.5 and 76.4%, respectively. Univariate analysis revealed that age >65 years was significantly associated with poorer 5-year OS (P<0.001) and DFS (P<0.001). Multivariate analysis revealed that an age of more than 65 years combined with high-grade histologic malignancy was associated with worse DFS (P=0.02; hazard ratio, 3.628; 95% confidence interval, 1.283-9.514). In conclusion, the clinical characteristics and treatment outcomes of parotid gland tumors were consistent with the results of previous reports. Smoking may be closely related to the pathogenesis of Warthin tumors. LBC potentially provides improved accuracy in FNAC.

Management and outcome of parotid mucoepidermoid carcinoma by histological grade: A 21-year review.

Objective: Mucoepidermoid carcinoma (MEC) is the most common malignancy of the parotid gland, but the outcome depends on the histological grade. Therefore, the aim of this study was to evaluate MEC on the basis of histological grade. Study Design: Retrospective analysis. Methods: We performed a retrospective analysis of data from patients whose initial treatment for MEC of the parotid gland was performed at our department between 1999 and 2021. We examined the association between the Armed Forces Institute of Pathology (AFIP) grade and outcome. Results: The AFIP grades were as follows: low, 26 cases; intermediate, 9 cases; and high, 31 cases. About 50% of cases were correctly diagnosed as malignant, and both grade and histology were accurately determined by fine-needle aspiration cytology in 20% of cases. The 5-year disease-free survival rate was 95.5% and 53.8% in the low-/intermediate- and high-grade cases, respectively. In the high-grade group, cases with recurrence were found to have a higher rate of lymph nodes metastasis than cases without recurrence. Furthermore, in this high-grade group, total sacrifice of the facial nerve did not reduce local recurrence. However, radical resection in the cases without tumor invasion to the nerve has decreased the local recurrence rate. The CRTC1-MAML2 fusion gene was expressed in 42.3% of low-/intermediate- and 14.3% of high-grade cases. Conclusions: The survival rate in MEC was quite different between the low-/intermediate- and high-grade cases. However, the rate of correct assessment of the grade by fine-needle aspiration cytology was poor. In high-grade cases, total sacrifice of the facial nerve may improve the rate of local recurrence in cases without invasion of the main trunk of the nerve. Expression of the CRTC1-MAML2 fusion gene could be helpful in not only the assessment of grade but the prediction of recurrence. Level of Evidence: 4.

Margin status, local control, and disease-specific survival in surgically resected parotid carcinomas with parapharyngeal extension.

BACKGROUND: Resection of parotid carcinomas involving the parapharyngeal space is challenging. How this affects tumor margin control, recurrence, and survival is unclear. METHODS: Patients who underwent resection of parotid carcinomas between 1985 and 2015 at Memorial Sloan Kettering Cancer Center were evaluated for the impact of parapharyngeal extension (PPE) on margin status, local recurrence-free probability (LRFP), and disease-specific survival (DSS). RESULTS: Out of 214 patients in whom preoperative imaging was available for review, 22 (10.3%) had PPE. Matched by histotypes, carcinomas with PPE had comparable margin positivity (p = 0.479), T classification (p = 0.316), pathologic risk (p = 0.936), and adjuvant therapy (p = 0.617) to those without PPE. The 3-year LRFP was 88.9% versus 95.4% (hazard ratio [HR] 2.23 after adjusting for pT classification, p = 0.342) and the 5-year DSS was 74.2% versus 69.5% (adjusted HR 0.45, p = 0.232) in patients with and without PPE. CONCLUSION: PPE does not appear to worsen oncologic outcomes in the resection of parotid carcinomas.

Basal cell adenocarcinoma of the parotid gland: Comparison with basal cell adenoma for preoperative diagnosis.

OBJECTIVE: To summarize the diagnosis and treatment outcomes of basal cell adenocarcinoma (BCAC) of the parotid gland, a rare low-grade malignancy, at a single institution, and to investigate the treatment approach for this rare malignancy. METHODS: We conducted a retrospective analysis of 9 patients with BCAC during 20 years from September 1999 to December 2019. Forty-five patients with basal cell adenoma (BCA), who were treated during the same time period, were used for comparison. The clinical characteristics of BCAC, diagnostic imaging, the usefulness of fine-needle aspiration cytology (FNAC) and frozen section biopsy (FSB), histological assessment of malignancy, and treatment outcomes were investigated. RESULTS: There were no marked differences in sex, age, tumor diameter, or tumor location between BCAC and BCA cases. Among the 9 patients with BCAC, one patient was noted with pain/tenderness, and two patients were observed with adhesion to the surrounding tissues. Only one patient was diagnosed as malignant based on MRI/US. FNAC for BCAC was suspicious for malignancy in 6 of the 9 cases, which included one patient with the correct grade of malignancy, one patient with malignancy only, and 4 patients suspicious for malignancy. FSB was suspicious for malignancy in 8 of the 9 cases. Malignancy grade was determined based on infiltration to the surrounding tissues and expression of Ki-67, p53, and bcl-2. One patient with infiltration to the surrounding tissue was diagnosed as intermediate-grade malignancy, while the remaining 8 patients were diagnosed as low-grade malignancy. The BCAC cases included 7 patients with T2 and 2 patients with T1. Conservative resection was performed for all patients, and all cases are surviving cancer-free. CONCLUSION: The malignancy of BCAC can be suspected before surgery based on symptoms/signs, diagnostic imaging, and FNAC. FSB enables the diagnosis of not only malignancy but also the grade of malignancy, which may help determine the appropriate surgical resection. Although all 9 patients with BCAC are surviving free from cancer, a long-term follow-up is warranted.