Incidental [18F]FDG-avid focuses in parotid glands on PET/CT

Abstract

Background

The number of unexpected focal [18F]FDG-avid findings (incidentalomas) within the parotid gland (PGI) continues to increase with the expanding use of PET/CT scanning. The prevalence of malignancy in PGIs is uncertain and appropriate management is unsettled.

Aims

We aimed to explore the underlying pathologies associated with PGI.

Materials and methods

A retrospective review of all patients with parotid gland incidentaloma(s) treated at the Ear-Nose-Throat Department, Aarhus University Hospital, Denmark in the period 2012–2021, was performed.

Results

In total, 94 patients with one (n = 86) or two (n = 8) PGI(s) were included. In patients with one PGI, 72 (84%) focuses were benign, two (2%) focuses were malignant (both malignant melanoma metastases), and 12 (14%) focuses were undiagnosed. In patients with two PGIs, all 12 lesions with pathological examinations were benign (4 PGIs were undiagnosed). The median SUV_max found in benign lesions was higher (12.0) compared to malignant lesions (5.5) (p = .043).

Conclusions and significance

The prevalence of malignancy was low (2/94, 2.4%) in PGIs. Based on our findings, PGI in patients without a history of parotid malignancy, who undergo PET/CT scanning for reasons other than head and neck cancer (including malignant melanoma), may be managed similarly to patients with asymptomatic parotid gland tumors.

Chinese Abstract

背景：腮腺内意外局灶性 [18F]FDG-avid发现（偶发瘤）(PGI)的数量随着 PET/CT 扫描的广泛使用而持续增加。PGI 中恶性肿瘤的发生率尚不确定, 适当的治疗也尚未确定。

目的：我们旨在探索与 PGI 相关的潜在病理学。

材料和方法：对所有在2012年至2021年期间在丹麦奥胡斯大学医院耳鼻喉科接受治疗的腮腺偶发瘤患者进行了回顾性分析。

结果：总共纳入了 94 名具有 1 个 (n=86) 或 2 个 (n=8) PGI 的患者。 在患有一个PGI的患者中, 72 个 (84%) 病灶为良性, 两个 (2%) 病灶为恶性（均为恶性黑色素瘤转移）, 还有 12 个（14%）病灶未确诊。 在有两个 PGI 的患者中, 所有 12 个病变的病理检查均呈良性（4 例 PGI 未确诊）。 良性病变的 SUVmax 中位数与恶性病变 (5.5) 相比, 病变率 (12.0) 更高 (p=.043)。

结论和意义：PGI 中恶性肿瘤的患病率较低（2/94, 2.4%）。 我们的研究结果显示, 对于没有腮腺恶性肿瘤病史、因除头颈癌（包括恶性黑色素瘤）以外的其他原因而接受 PET/CT 扫描的患者, 可以采用与治疗无症状腮腺肿瘤患者类似的方法来治疗。

Keywords:

• PET/CT
• incidentaloma
• parotid gland
• malignancy

Acknowledgement

None.

Authors´ contributions

TEK: Initiation and design of the study; analysis and interpretation of the results; drafting and approval of the manuscript; accountable for all aspects of the work. SH: Data extraction; critical revision and approval of the manuscript; accountable for all aspects of the work. AHG: Data extraction; critical revision and approval of the manuscript; accountable for all aspects of the work. LCG: Interpretation of the results; critical revision and approval of the manuscript; accountable for all aspects of the work. PK: Data extraction; analysis and interpretation of the results; critical revision and approval of the manuscript; accountable for all aspects of the work.

Ethics approval

The study was approved by the Danish Patient Safety Authority (#1-45-70-27-21). The study was performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki.

Consent to participate

Not applicable.

Consent for publication

Not applicable.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Availability of data and material

Anonymized data can be obtained from the corresponding author upon request.