Salivary Duct Carcinoma Arising in a Warthin Tumor of the Parotid Gland: A Rare Case Report with Review of Literature and PD-L1 Expression

We describe an extremely rare case of salivary duct carcinoma arising in a Warthin tumo r in a 64-year-old male. Patient presented with an enlarging left parotid mass, biopsy of which showed salivary duct carcinoma. He subsequently underwent left parotidectomy along with left level II–IV lymph node dissection. Histology revealed both in situ as well as invasive salivary duct carcinom a arising from Warthin tumor. Immunohistochemistry showed tumor cells positive for CK7, AR, and GATA3, while p63 highlighted the myoepithelial cell layer in the in situ component. Her2 was 2+ by immunohistochemistry. In addition, PD-L1 IHC revealed positive expression with a combined positive scor e of 20%.
Source: Head and Neck Pathology - Category: Pathology Source Type: research