Clinicopathological characterization of primary oral and sinonasal melanoma in a referral centre in Mexico City: 2000-2012.

In Mexico, there have been few studies on primary oral and sinonasal melanoma, an aggressive neoplasm with a low survival rate and few therapeutic alternatives. Further, there is limited information about its clinical and histopathological characteristics. The aim of this retrospective study was to describe the clinicopathological profile of these tumours in patients attending a major oncology reference centre in Mexico City over a 12-year period. Demographic and clinical data were obtained from the clinical charts, and histopathological features were evaluated. χ(2), Fisher's exact, and Mann-Whitney U-tests were used for analysis; significance was set at P<0.05. Thirty-three cases were studied (73% sinonasal melanoma (SNM) and 27% oral melanoma (OM)); 58% were female and the median age was 66 (Q1-Q3 55.5-75) years. Compared with OM patients, SNM patients had a shorter time to diagnosis (16.7 vs. 11.7 months, P=0.022), were identified at earlier stages (33.3% vs. 58.3%, P=0.010), and all presented symptoms (66.7% vs. 100%, P=0.015). All samples showed vertical growth and 96.9% exhibited pleomorphism. A higher proportion of cases with pleomorphism developed metastases at follow-up than those without (60% vs. 12.5%, P=0.026). The present study provides valuable information that could form the basis of future studies in the search for advanced therapy modalities.