Prospective study of the pattern of lymphatic metastasis in relation to the submandibular gland in patients with carcinoma of the oral cavity

Background The submandibular gland is responsible for 70% to 90% of unstimulated saliva production. Its excision causes a decrease in basal salivary flow resulting in increased symptoms of subjective xerostomia and decreased quality of life. In this study, we have tried to assess the pattern of nodal metastasis in relation to the submandibular gland. With this study, we have tried to find out whether submandibular gland preservation is a viable option in patients with carcinoma of the oral cavity. Methods This was a prospective study conducted in a tertiary care cancer center. The fibrofatty tissue surrounding the submandibular gland was divided into 6 parts depending upon its location with the submandibular gland. All these 6 parts along with the submandibular gland were separately sent for histopathological analysis. Metastasis pattern in level Ib region was noted. Result The study included 137 patients with carcinoma of the oral cavity who underwent neck dissections. Eighty-five patients had clinic-radiologically N0 neck, 52 patients had cN+ (clinically node positive) neck. Level Ib was involved in 8.2% of the cases with cN0 (clinically node negative neck). In patients with cN+ neck, level Ib metastasis was seen in 40% of the cases. Metastasis in N0 necks in the area deep to the submandibular gland was seen in only 1 case (9% of all pathologically node-positive patients) with cN0 neck. This was the only case in which submandibular gland mobilization would have been required to take out the metastatic node. Even in cases with N+ neck, deep metastasis was seen in 4 cases only (14.8%). None of them had a primary tumor in the tongue. Therefore, there is a possibility of preserving the submandibular gland in cases of carcinoma of the tongue. Conclusion Involvement of level Ib in early tongue cancers is not very common and direct metastases to the submandibular glands are rare. Even when metastasis is present in level Ib, it can be excised without affecting the submandibular gland. In early tongue lesions, submandibular gland mobilization for dissection at level Ib is not required as no metastases deep to the submandibular glands were seen in these patients. © 2016 Wiley Periodicals, Inc. Head Neck, 2016