Is Intratumoral (IT) or Peritumoral (PT) Lymphangiogenesis in Low-Grade Salivary Gland Carcinomas Significant?
A Samad, C Singh, JC Manivel, R Gamez, IG Koutlas, SE Pambuccian. Uni of Minnesota, Minneapolis, MN
Background: The prognosis of mucoepidermoid (MEC), acinic cell (ACC) and adenoid cystic carcinoma (ADCY) is dependent on tumor size, nodal metastases and grade. Nodal metastases correlate with lymphatic density (LD) in some tumors like prostate and colon carcinoma but no data on lymphangiogenesis are available in salivary gland carcinomas. The aim of this study was to assess IT or PT lymphatic densities in MEC, ADCY, ACC as compared to pleomorphic adenomas (PA) and determine any relationship between LD and nodal metastases in these tumors.
Design: All ADCY, MEC, ACC and a matching number of PA diagnosed during a 10 year period in our institute were identified and reviewed. Blocks containing normal and tumor interface were immunostained with D-2-40 (Biocare Medical) using Ventana Benchmark XT. Two reviewers quantified lymphatic density (averaged from number of lymphatics in 4 high power fields in “hot spots” identified at low power) in IT and PT tissue (within 10-mm around tumor).
Results: 73% of all malignant tumors and 100% of PA originated in the parotid. 9 cases (6 MEC, 2 ACC, 1 ADCY) had lymph node metastases (LN+) at diagnosis. The lymphatic density is significantly higher in the PT tissue compared to the tumor (p<0.0001) for MEC, ADCY, ACC and PA. The IT and PT lymphatic densities between different malignancies do not show any significant difference (p>0.05) and were not different than the same measurements in PA.