Primary mucin-producing tumours of the salivary glands: A clinicopathological and morphometric study

Aims: To determine clinicopathological and morphometric features that discriminate between mucin-producing primary salivary gland carcinomas. Materials and results: Fifteen mucin-producing tumours were stratified into five colloid carcinomas (CCs), four mucinous cystadenocarcinomas (MCAs), three mucin-rich salivary duct carcinomas (SDCs) and three mucin-rich mucoepidermoid carcinomas (MECs). The mean patient age was 70, 58, 43 and 63 years for CC, MCA, SDC and MEC, respectively. Eleven of 15 patients were female. The majority of CC cases originated from major salivary glands; MCA showed a predilection for the minor salivary glands. No disease-related mortality was observed in the CC group; one patient died in the MCA group, and one in the SDC group. Receiver-operating characteristic curve analysis revealed an optimal cut-off point of 17% of the tumour cells in contact with stroma that best distinguished between the CC and MCA. Histomorphometric measurements revealed that CC was best differentiated from MCA by smaller nuclear size and more regular chromatin. Conclusions: Strict morphological criteria of CC coupled with assessment of the tumour cell/stroma relationship and the nuclear features facilitate discrimination between mucinous tumours of salivary gland.