Parotid incidentalomas: a systematic review

Abstract

Objective Parotid incidentalomas on fluorodeoxyglucose positron emission tomography/computed tomography imaging are rare. A systematic review was performed to assess their aetiology and association with scanning indication, and to develop an evidence-based algorithm for their management. Methods A literature search was performed on 25 August 2020 using the keywords ‘incidentaloma’, ‘incidental finding’, ‘parotid’, ‘parotid gland’, ‘salivary gland’ and ‘head and neck’. Articles were reviewed by two authors before their inclusion. Results Forty articles were included, totalling 558 incidentalomas. The mean incidence was 0.74 per cent. Lung cancer was the most common imaging indication. The most common aetiologies were cystadenolymphoma, pleomorphic salivary adenoma and metastases. Only cystadenolymphoma (p = 0.015) and pleomorphic salivary adenoma (p = 0.011) were significantly associated with a primary malignancy (lung). The most common further investigations were aspiration cytology, ultrasound imaging and core biopsy, usually prior to parotidectomy. Conclusion If appropriate, parotid incidentalomas should be followed up with flexible endoscopy, skin examinations, and head and neck examinations. Ultrasound-guided core biopsy provides higher accuracy, avoiding repeat sampling and excision biopsy.

Incidentally found parotid gland lesion in 18F-FDG PET/CT for staging evaluation of patients with hepatocellular carcinoma: remote possibility of metastatic tumor or second primary salivary gland malignancy

“…According to a recent systematic review, the overall prevalence of PIL in various primary tumor staging examinations using 18 F-FDG PET/CT was 0.74%, with a significantly higher frequency observed in patients with lung cancer [ 16 ]. In our study, PIL was detected in 2.7% of patients with HCC, showing a higher prevalence compared with other non-head and neck primary cancers, and a higher likelihood of detection in patients with head and neck cancer (2.1%) [ 3 ].…”

“…According to the aforementioned systematic review by Thompson and colleagues, the majority of tumors found in cases wherein histological confirmation was available were benign, such as Warthin tumor (cystadenoma). However, malignant lesions were identified in approximately 30% of cases, including metastatic LNs and primary parotid gland malignancies [ 16 ]. In contrast, among the 54 patients in our study who underwent histological confirmation for PIL, no malignant lesions were found.…”

Association of Ultrasonography With Final Histopathology in Diagnosing Thyroid Malignancy: A Single-Institute Retrospective Study

“…The diagnosis of thyroid nodules continues to present significant challenges for treating physicians. The frequent use of high-resolution ultrasound (US) in conjunction with carotid Doppler techniques revealed the existence of an increasing number of incidentalomas or asymptomatic thyroid nodules [ 4 ]. The sensitivity of the US is high for identifying the nodules, and the US characteristics of the nodules can help determine whether further investigation is required [ 5 ].…”