Clonal Pattern of Metastasis in a Case of Malignant Mucoepidermoid Tumour of the Palatal Salivary Gland

Abstract

A case of metastasizing mucoepidermoid tumour of the palatal salivary glands is presented. The disease was characterized by a protracted course of local recurrences, metastases in regional lymph nodes and an uncontrollable distal spread at the terminal stage. Some of the metastases were histologically pure mucus-producing adenocarcinomas and some were pure epidermoid forms without glandular structures. Characteristic intermingled patterns were also seen. This clonal pattern is taken to indicate a mosaic structure in the original tumour with subpopulations endowed with varying differentiative capacities. The existence of such almost “monotypic” forms of mucoepidermoid tumour is important to keep in mind in the practical work.