Metastases of Cutaneous Squamous Cell Carcinoma Seem to be the Most Frequent Malignancies in the Parotid Gland: A Hospital-Based Study From a Salivary Gland Center

Abstract

Malignant parotid tumors account for approximately 20% of all parotid lesions. In addition to the various primary parotid lesions there are secondary parotid malignancies, such as metastases or lymphomas. Data on histopathological distribution of all malignancies-including secondary parotid lesions-is limited. Recent evidence indicated a rising surgical incidence of secondary parotid malignancies. This study aims to review the distribution of malignancies in parotid resections from a salivary gland center. A retrospective review of prospectively collected data for all patients who had received parotidectomy between 2014 and 2019 was performed. Histopathological distribution was displayed separately for all parotid malignancies and for primary parotid malignancies. Further, patients` characteristics were compared between benign and malignant parotid lesions and between the two most common malignant parotid lesions. Out of 777 patients, 614 (78.9%) patients had a benign and 164 (21.1%) patients had a malignant parotid lesion. The most common parotid malignancy was metastatic cutaneous squamous cell carcinoma (cSCC) accounting for 35.4% of all parotid malignancies. 71.5% of all malignant lesions were secondary malignancies. Patients with metastatic cSCC were significantly older (p < 0.001) and significantly more likely to be male (p < 0.001) than patients with primary parotid malignancies. No significant difference was found when the lesion size of metastatic cSCC was compared to primary parotid malignancies (p = 0.216). The present study shows the high prevalence of secondary parotid malignancies in patients who had received parotidectomy. Furthermore, it confirms a rising surgical incidence of metastatic cSCC to the parotid gland in a series from a salivary gland center. At this time, parotid surgery for malignant lesions is more likely to be performed for metastases than for primary parotid malignancies.

Clinico-Epidemiological Analysis of Most Prevalent Parotid Gland Carcinomas in Poland over a 20-Year Period

“…Parotid gland SCC is thought to be more often metastatic cutaneous SCC rather than primary disease [ 40 , 61 , 62 ]. Generally it is thought to be a rare type among primary parotid pathology, however, it is considered highly malicious [ 61 , 63 , 64 ], but some epidemiological studies confirm the significant share of SCC among malignancies of parotid gland, especially when only metastases are analysed [ 65 , 66 , 67 , 68 ]. In the study of Mayer et al [ 67 ], SCC accounted for 35.4% of all parotid malignancies, a very similar result to the above analysis.…”

“…Generally it is thought to be a rare type among primary parotid pathology, however, it is considered highly malicious [ 61 , 63 , 64 ], but some epidemiological studies confirm the significant share of SCC among malignancies of parotid gland, especially when only metastases are analysed [ 65 , 66 , 67 , 68 ]. In the study of Mayer et al [ 67 ], SCC accounted for 35.4% of all parotid malignancies, a very similar result to the above analysis. However, it should be emphasised that the vast majority of parotid SCCs are metastases from other sites, and they account for up to 86% of all salivary SCC [ 65 , 68 ].…”

Trichilemmal carcinoma metastatic to parotid gland: First report of fine needle aspiration cytology features

“…9 Cutaneous SCC is globally the most frequent histological type of cancer to metastasize to parotid, followed by melanoma. 10 However, the same is not true in the Indian scenario where these cancers are uncommon owing to high skin pigmentation. The largest Indian study on tumours metastatic to the parotid found eyelid sebaceous carcinoma, another malignant skin appendageal tumour, to be the most frequent metastatic tumour in the parotid.…”

The Milan system for reporting salivary gland cytopathology—A single‐center study of 2156 cases

“…Salivary gland (SG) tumors are rare, representing about 3% of all tumors in the head and neck region worldwide 1,2 . Since the beginning of routine application of fine‐needle aspiration cytology (FNAC) in Sweden at the Karolinska institute in 1964, it has gained importance in the diagnostic workup of SG lesions and is here to stay 3 .…”