Purpose: Metastasising pleomorphic adenoma (MPA) is a rare malignant tumour that can affect multiple organs with a considerable time latency compared to primary pleomorphic adenoma (PA). To date, MPA and its clinical course, including survival and relapse rates, are still poorly understood.

Methods: We performed a systematic literature review following the PRISMA 2020 guidelines. The research was carried out using the PUBMED database and the following search terms: ((Metastatic) OR (metastases) OR (metastasis) OR (metastasizing)) AND (pleomorphic adenoma). The inclusion criteria for the final selection were: case reports or case series as study designs, availability of full text, and diseases specific to the parotid gland. Review articles, articles without full text, and studies on salivary glands other than the parotid gland were excluded.

Results: A total of 908 papers were initially selected and 42 patients. The mean age at the diagnosis of MPA was 49.2 years (range 13-75 years). The average interval of onset of first metastasis was 15.7 years (range 1.4-45 years). The most common sites of metastasis were the bones (23.8%) and lungs (23.8%). In 31 patients (73.8%) a surgical treatment for complete removal of MPA was performed, while 10 patients withstood definitive or adjuvant radiotherapy. The follow up status was described only in 22 out of 40 papers where only 3 patients died from the neoplasm.

Conclusion: MPA of the parotid gland is a rare condition. The transformation of a PA to MPA is unpredictable. Because of the scarcity of data in the literature, the long-term behaviour of metastatic neoplasm is uncertain. However, we found that 5 out of 19 patients experienced disease relapse after treatment. Additionally, the average survival rate for individuals with MPA of the parotid gland is 64% after 5 years. The preferred course of treatment, if possible, is the surgical removal of the neoplasm.

Keywords: Metastasising pleomorphic adenoma; Oncology; Parotid gland; Parotid surgery; Pleomorphic adenoma.

© The Author(s) 2025.

目的： 恶性多形性腺瘤（MPA）是一种罕见的恶性肿瘤，可以影响多个器官，并且与原发性多形性腺瘤（PA）相比，在发病时间上有较长的时间延迟。迄今为止，关于MPA及其临床过程，包括生存率和复发率等方面仍缺乏深入了解。

方法： 我们按照PRISMA 2020指南进行了系统文献回顾。研究通过PUBMED数据库进行，并使用以下搜索词：((Metastatic) OR (metastases) OR (metastasis) OR (metastasizing)) AND (pleomorphic adenoma)。最终筛选的纳入标准是：病例报告或案例系列作为研究设计，全文可获取以及特指腮腺疾病的文献。排除综述文章、无全文的文章以及非腮腺唾液腺的研究。

结果： 初步选择了908篇论文，并确定了42例患者。MPA诊断时的平均年龄为49.2岁（范围13-75岁）。首次转移发生的时间间隔平均为15.7年（范围1.4-45年）。最常见的转移部位是骨骼（23.8%）和肺部（23.8%）。在31例患者（73.8%）中进行了手术治疗以完全切除MPA，而有10名患者接受了根治性或辅助放射治疗。只有40篇论文中的22篇描述了随访状态，在这些论文中仅有3名患者死于该肿瘤。

结论： 腮腺的MPA是一种罕见的情况。从PA转变为MPA是不可预测的。由于文献数据稀缺，关于转移性肿瘤的长期行为尚不确定。然而，我们发现有5例（占19%）患者在治疗后经历了疾病复发。此外，腮腺MPA个体的平均五年生存率为64%。如果可能的话，首选治疗方法是手术切除肿瘤。

关键词： 恶性多形性腺瘤；肿瘤学；腮腺；腮腺手术；多形性腺瘤。