Secretory carcinoma around Stensen's duct misdiagnosed as salivary duct cyst.

Secretory carcinoma (SC) of the salivary gland was identified in 2010, and it is characterized by a specific ETV6 gene arrangement. The most common primary site for SC is the parotid gland; however, SC around the Stensen's duct is rare. Here we describe a rare case of a SC around the Stensen's duct that was initially misdiagnosed as a salivary duct cyst. A 59-year-old woman presented with a mass in the region of the left parotid papilla. Magnetic resonance imaging (MRI) revealed a well-circumscribed lesion and enhancement with a rim and an inner wall-like part that appeared in the late phase. Based on the initial clinical and imaging findings, a salivary duct cyst of the parotid gland was diagnosed. However, the lesion was histopathologically diagnosed as a SC based on immunohistochemical findings. The tumor cells showed diffuse positive staining for AE1/AE3, vimentin, and mammaglobin and focal positive staining for S-100 protein, SOX-10, and DOG-1. Fluorescence in-situ hybridization revealed ETV6 gene rearrangement in the tumor. In cases of cystic lesions around the Stensen's duct, clinicians should bear in mind that the possibility that they could be minor salivary gland cancers, such as SC.
Competing Interests: None.
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