Assessment of Immunoreactivity Patterns in the Excised Cervical Lymph Nodes of Oral Squamous Cell Carcinoma

Introduction: Epidermoid carcinoma (oral squamous cell carcinoma [OSCC]) comprises approximately 80% of the malignancies of the oral cavity, which is also responsible for the morbidity and mortality due to the distant spread of the neoplastic cells. The regional draining lymph node has been considered an anatomic barrier to the systemic dissemination of malignant cells. It has been postulated that the microscopic architectural pattern of a regional lymph node (RLn) represents the immunologic reactivity in that node and the host response. Morphological assessment of the regional nodes aids in a better understanding of the immune response and its correlation with the stage of the tumour. Materials and Methods: A total of 51 head-and-neck dissection cases were assessed for immunomorphological patterns and the degree of tumour involvement in positive lymph nodes. 49 lymph nodes were in the early stage (TNM Stage l and ll) and 71 lymph nodes were in the advanced stage(TNM stage lll and lV). A total of 595 lymph nodes were histologically evaluated and were categorised into metastatic and non-metastatic nodes showing four different patterns: lymphocyte predominance (LP) pattern, germinal centre predominance (GCP) pattern, sinus histiocytosis (SH) pattern and lymphocyte-depleted pattern. Results: The most frequently encountered pattern of lymph nodes was of LP (436 nodes), followed by GCP (61 nodes), SH (36 nodes) and lymphocyte depleted (18 nodes), respectively. Out of 595, 120 nodes were positive for metastasis, indicating that as the stage advances, the GCP type predominates (the predominant immunomorphological pattern shifts from LP to GCP), facilitating metastasis. Conclusion: Immunomorphological changes in the RLns of OSCCs seem to be pivotal factors that serve as an important prognostic indicator. Whereas the cell-mediated immune response represented by LP and SH appears to resist the metastasis process, the humoral response reflected by GCP favours metastasis.