Polymorphous low grade adenocarcinoma with distant metastases and deletions on chromosome 6q23-qter and 11q23-qter: a case report

Polymorphous low grade adenocarcinomas (PLGAs) are thought to be indolent tumours that are localised preferentially to the palate and affect the minor salivary glands almost exclusively. Metastases to locoregional lymph nodes occur in only 6-10% of cases. Recently, two cases of PLGA with microscopically confirmed distant metastases have been reported. This study reports a third case of PLGA with histologically and immunohistochemically confirmed distant metastases. It is the first case with multiple pleural, as well as pulmonary parenchymal, metastases and metastases in cervical and paraoesophageal lymph nodes. In most cases, PLGAs are salivary gland tumours with limited potential to metastasise and a good prognosis after local treatment. However, the recently reported cases reveal that the tumour can give rise to widely spread metastases. To obtain more information about the incidence of distant metastases, periodic chest x ray examination during follow up is desirable.