Myopericytoma of the Parotid and Molecular Profiling: Report of a Rare Case and Review of the Literature

Myopericytomas are uncommon tumors defined by their round to spindle shaped cells often arranged in a concentric pattern of perivascular growth. They are typically well-circumscribed, nodular, slow-growing lesions that occur in the soft tissue of the extremities. Here, we present a 30-year-old female with a 2.4 cm myopericytoma occurring in the deep lobe of the parotid gland. The diagnosis was made with detailed histopathologic and immunohistochemical findings and positive identification of the specific mutation for PDGFRβ p.Asp666Lys by next generation sequencing (NGS). This is the first case report of a parotid myopericytoma with a genetic testing that shows a particular mutation that has been linked to myopericytomatosis.

Use of Propensity Score Matching to Compare Short Outcomes from Transoral and External Surgical Approaches in Patients with Deep-Lobe Parotid Pleomorphic Adenomas

To compare the outcomes of patients who had deep-lobe parotid gland pleomorphic adenomas (PAs) that extended into the parapharyngeal space after surgical treatment, using a transoral approach or an external approach. One hundred and twelve eligible patients, with deep-lobe parotid gland PAs, were enrolled in this retrospective study. The surgical outcomes were compared for patients who received a transoral approach and an external approach, using 1:1 propensity score matching (PSM). The outcome measures were recurrence rate, facial nerve deficit, Frey’s syndrome, and hospitalization time. The median follow-up time was 4.8 years. After PSM, the transoral approach and external approach groups had no statistically significant difference in recurrence (10.3% vs. 3.4%; p = 0.201). The transoral approach group had no facial nerve deficit, but 5 of 29 patients (17.2%) in the external approach group had transient facial nerve paralysis (p = 0.052). The external approach group had a longer hospitalization time than the transoral approach group (5 vs. 4 days, p = 0.0017). The use of a transoral surgical approach to treat patients with deep-lobe parotid gland PAs led to low recurrence, shorter hospitalization times, and good functional and cosmetic outcomes.

Deep Lobe Parotid Tumors: A Systematic Review and Meta-analysis

Objective We performed a systematic review and meta-analysis of deep lobe parotid tumors to evaluate their unique characteristics. Data Sources PubMed/Medline, Embase, Web of Sciences, and Cochrane Library databases were queried for relevant literature. Review Methods Studies were individually assessed by 2 independent reviewers. Risk of bias was assessed with the Cochrane bias tool, GRADE criteria, and MINORS criteria. Results were reported according to the PRISMA guidelines. Statistical analysis was performed by comparing rates of malignancy between deep and superficial lobe tumors. Results In total, 8 studies including 379 deep lobe parotid tumors met inclusion criteria. Mean age at diagnosis was 44.9 years. Computed tomography scan was the most common imaging modality. Preoperative diagnostic fine-needle aspiration was utilized in 39.4% of patients and demonstrated high sensitivity for malignant disease. The most common approach was subtotal parotidectomy with facial nerve preservation (58.9%). The rate of malignancy was 26.6%, which was significantly higher than that of the superficial lobe tumors in this study (risk ratio, 1.25; 95% CI, 1.01-1.56). The rate of temporary postoperative facial nerve weakness between deep and superficial lobe tumors was 32.5% and 11.7%, respectively. Conclusion Deep lobe parotid tumors had a 26.6% rate of malignancy. On meta-analysis, deep lobe tumors appeared to have higher rates of malignancy than superficial lobe tumors. Surgical excision of deep lobe tumors showed increased rates of temporary facial nerve paresis as compared with superficial lobe tumors. Computed tomography scan was the most common imaging modality. There were limited data regarding the utility of fine-needle aspiration.

Dynamic Three-Dimensional ADC Changes of Parotid Glands During Radiotherapy Predict the Salivary Secretary Function in Patients With Head and Neck Squamous Carcinoma

ObjectiveTo investigate the changes of three-dimensional apparent diffusion coefficient (3D-ADC) of bilateral parotid glands during radiotherapy for head and neck squamous cell carcinoma (HNSCC) patients and explore the correlations with the radiation dose, volume reduction of parotid gland and the salivary secretary function.Materials and Methods60 HNSCC were retrospectively collected in Sichuan cancer hospital. The patients were all received diffusion-weighted imaging (DWI) scan at pre-radiation, the 15th radiation, the 25th radiation and completion of radiation. Dynamic 3D-ADC were measured in different lobes of parotid glands (P1: deep lobe of ipsilateral; P2: superficial lobe of ipsilateral; P3: deep lobe of contralateral; P4: superficial lobe of contralateral), and the 3D-ADC of spinal cord were also recorded. Chewing stimulates test, radionuclide scan and RTOG criteria were recorded to evaluate the salivary secretary function. Pearson analysis was used to assess the correlation between 3D-ADC value, radiation dose, volume change, and salivary secretary function.ResultsThe mean 3D-ADC of parotid glands increased. It began to change at the 15th radiation and the mostly increased in P1. However, there was no change for the maximum and minimum 3D-ADC. The 3D-ADC values of spinal cord changes were almost invisible (ratio ≤ 0.03 ± 0.01). The mean 3D-ADC was negatively correlated with the salivary secretary function (r=-0.72) and volume reduction of different lobes of parotid glands (r1=-0.64; r2=-0.61; r3=-0.57; r4=-0.49), but it was positively correlated with the delivered dose (r1 = 0.73; r2 = 0.69; r3 = 0.65; r4 = 0.78).ConclusionDynamic 3D-ADC changes might be a new and early indicator to predict and evaluate the secretary function of parotid glands during radiotherapy.