High-grade papillary cystadenocarcinoma of the tongue

Aims: Salivary gland tumours of the tongue are rare. The most common type is low‐grade mucoepidermoid carcinoma followed by adenoid cystic carcinoma. Papillary cystadenocarcinoma of salivary glands are uncommon lesions with low‐grade histological and clinical features. We report a high‐grade papillary cystadenocarcinoma in an 80‐year‐old man who presented with a tongue mass and metastatic disease in the neck. Methods and results: He was treated with partial glossectomy and bilateral neck dissection but developed local and regional recurrences 6 months later. The tumour had a prominent cystic appearance and had areas of necrosis. The cyst lumen was occupied by numerous papillae lined by pseudostratified columnar cells with a high nuclear–cytoplasmic ratio. The cytoplasm was eosinophilic, the nuclei were pleomorphic and exhibited irregular nuclear membranes, vesicular chromatin and prominent eosinophilic nucleoli. The mitotic activity was high and there were occasional abnormal mitotic figures. Metastatic carcinoma was present in four lymph nodes. The differential diagnosis of this unusual lesion includes cystadenoma, salivary duct carcinoma and metastases. Conclusions: This case and a review of the literature indicates that papillary cystadenocarcinomas of salivary gland origin exhibit a wider morphologic spectrum than described in the latest World Health Organization (WHO) classification which defines these lesions as low‐grade neoplasms.