Salivary duct carcinoma- Role of accurate diagnosis for an accurate therapy

Abstract

Salivary duct carcinoma is an aggressive subtype of primary salivary gland carcinoma with advanced stage at presentation, high rates of metastasis and recurrence. It is most commonly seen in parotid gland of older men with microscopic resemblance to high-grade breast ductal carcinoma. Salivary duct carcinoma mainly affects men over 50 years of age and accounts for 5% to 10% of all salivary gland malignancies. Characteristic histomorphology and immunohistochemical expression of Androgen Receptor (AR) aids the diagnosis of salivary duct carcinoma. Fine-needle aspiration typically reveals cytologic features of high-grade carcinoma. Heterologous alterations have been recognized in oncogenes and tumor suppressor genes such as TP53, HRAS, PIK3CA, PTEN, and BRAF as well as AR and HER2. Targeted therapy against these genes may help in broadening treatment options for salivary duct carcinoma. Salivary Duct Carcinoma is one of the most aggressive salivary malignancies with 33% local recurrence and 45% metastasis. We report a case of a 75 years old female patient, who presented with a swelling obliterating the retromandibular groove. FNAC & histopathology confirmed the diagnosis of salivary duct carcinoma.