Rare cases of Multiple Retention Cysts of minor salivary glands
Purpose: We present 2 rare cases of multiple retention cysts of minor salivary glands.
Methods: Case 1: a 59-year-old man was referred for a slightly painful swelling of the left cheek. Examination revealed a 2cm large erythematous submucosal nodule under the left commissure, and multiple bilateral 0,5 to 2cm firm bluish nodules in upper and lower lips and adjacent cheek, covered by a smooth mucosa with an occasional excretory duct. They had been present for at least 20 years. Case 2: a 74-year-old woman treated for depression was referred for a traumatic gingival lesion. Examination revealed also multiple bilateral painless, freely movable submucosal nodules in the upper and lower lip and under the right commissure. Two biopsies were performed in Case 1 and one in Case 2.
Results: Histological features were similar in both cases. The sections showed multiple cysts of different size in the parenchyma of minor salivary glands or in the nearby connective tissue. They were lined by a columnar or cubical epithelium of variable thickness with occasional mucous cells and large areas of oncocytic cells. The cysts contained saliva mixed with some inflammatory cells. In Case 2 one cyst contained an inspisssated mucous plug. Pericystic connective tissue was more or less fibrotic and contained areas of chronic lymphocytic infiltrate of variable density, with occasional germinal centres in Case 1. The adjacent glandular parenchyma was normal, or contained a mild lymphoplasmocytic inflammatory infiltrate, with some dilated ducts and dedifferentiated acini.
Conclusion: Multiple retention oral cysts are very rare, or published with other names: we found only 1 article about 2 cases. Differential histological diagnosis includes glandular cheilitis, cystadenoma, and intraoral Warthin tumour. They could be related to an abnormally viscous saliva causing blockage, or to an anomaly of the ducts. Diagnosis is important to avoid multiple unnecessary surgical operations.