Metastatic behaviour of sinonasal adenocarcinomas of the intestinal type (ITAC).

The relative frequency of regional lymphogenic versus distant hematogenic metastases was evaluated in 369 patients with sinonasal adenocarcinoma of the intestinal type (ITAC). We assessed the results of neck dissections for a limited number of patients undergoing this surgical intervention. 117 ITAC patients were followed up for at least 5 years. Neck dissections were performed in 18 cases (15 primary and 3 secondary operations), 4 of which revealed carcinoma-positive lymph nodes. Metastases in lymph nodes were also diagnosed clinically in three other patients adding up to a total of seven individuals (6 % of 117) with lymphogenic metastases. In comparison, distant hematogenic metastases were identified in 15.4 % of these 117 patients. In the second group of 252 patients, the occurrence of distant hematogenic metastases and colorectal adenocarcinomas was registered but no formal follow-up procedure was applied. 50 neck dissections were performed in this group, 46 of which exhibited no histological evidence for metastases in lymph nodes, while in 1 case they were carcinoma-positive. Three additional cases showed clinical signs of metastases in regional lymph nodes. Taken together, our observations indicate that regional lymphogenic metastases are rather rare (about 2 %) in patients with sinonasal adenocarcinoma of the intestinal type. Therefore, the surgery of neck dissection appears not advised as routine intervention in these cases. ITAC patients show a normal prevalence of colorectal adenocarcinomas.