Review and characteristics of 585 salivary gland neoplasms from a tertiary hospital registered in the Polish National Major Salivary Gland Benign Tumors Registry over a period of 5 years: a prospective study

Concurrent Warthin tumor and Kimura disease: a case report

BACKGROUND

Warthin tumor (WT) is a common benign salivary tumor of the parotid gland. Clinically, it occurs in men in their fifth to seventh decades who typically smoke cigarettes. WTs have been reported with different head and neck neoplasms and other salivary gland tumors within the same or another salivary gland. Kimura disease (KD) is a rare chronic inflammatory disease with unknown etiology affecting young to middle-aged Asian men. KD presents as an asymptomatic nodule in the head and neck area, with regional lymphadenopathy and salivary gland involvement.

CASE PRESENTATION

A 64-year-old Arabic man presented with a 10-year history of an asymptomatic swelling of the left face. Computed tomography showed a well-defined, multicystic mass with heterogeneous enhancement. The resected mass was composed of two distinct components. There was a well-demarcated proliferation of papillary and cystic oncocytic epithelium with lymphoid stroma, consistent with WT. Some areas exhibited sclerotic fibrosis, with multiple lymphoid follicles showing folliculolysis, follicular hyperplasia, and eosinophilic infiltrate. The patient's immunoglobulin E level serum was elevated, confirming a coexisting KD. The patient underwent a left superficial parotidectomy, with no recurrence at a 30-month follow-up.

CONCLUSION

This report describes the first concurrent case of WT and KD in the parotid gland.

Global DNA Methylation Profiling Reveals Differentially Methylated CpGs between Salivary Gland Pleomorphic Adenomas with Distinct Clinical Course

Pleomorphic adenomas (PAs) are the most frequently diagnosed benign salivary gland tumors. Although the majority of PAs are characterized by slow growth, some develop very fast and are more prone to recur. The reason for such differences remains unidentified. In this study, we performed global DNA methylation profiling using the Infinium Human Methylation EPIC 850k BeadChip Array (Illumina) to search for epigenetic biomarkers that could distinguish both groups of tumors. The analysis was performed in four fast-growing tumors (FGTs) and four slow-growing tumors (SGTs). In all, 85 CpG dinucleotides differentiating both groups were identified. Six CpG tags (cg06748470, cg18413218, cg10121788, cg08249296, cg18455472, and cg19930657) were selected for bisulfite pyrosequencing in the extended group of samples. We confirmed differences in DNA methylation between both groups of samples. To evaluate the potential diagnostic accuracy of the selected markers, ROC curves were constructed. We indicated that CpGs included in two assays showed an area under the curve with an acceptable prognostic value (AUC > 0.7). However, logistic regression analysis allowed us to indicate a more optimal model consisting of five CpGs ((1) cg06748470, (2) cg00600454, (3) CpG located in chr14: 77,371,501−77,371,502 (not annotated in GRCh37/hg19), (4) CpG2 located in chr16: 77,469,589−77,469,590 (not annotated GRCh37/hg19), and (5) cg19930657) with AUC > 0.8. This set of epigenetic biomarkers may be considered as differentiating factors between FGT and SGT during salivary gland tumor diagnosis. However, this data should be confirmed in a larger cohort of samples.