A late solitary liver metastasis from pleomorphic salivary adenoma

Pleomorphic adenoma (also known as mixed tumour) is the most common neoplasm of the salivary glands. it is usually a benign, slow-growing and well-circumscribed lesion. Metastasizing pleomorphic salivary adenoma is extremely rare, occurring in less than 1% of patients with pleomorphic adenoma. There are very few reports of a subset of these tumours metastasizing to distant sites without undergoing malignant transformation. There are as yet no statistics for this pathology - some aspects continue to be controversial and any patient may represent a diagnostic dilemma for the surgical oncologist and the cancer pathologist. A definitive diagnosis usually requires radical surgery, if possible. We present a review of the literature and an unusual case of a large liver mass found incidentally in an 87-year-old female. The patient was eligible for surgery and a successful liver resection was performed. The liver tumour was found to be a very large metastasis of pleomorphic adenoma with unharmed resection margins. This diagnosis is extremely rare and our patient seems to represent the oldest case described to date.