Evaluation of lymph node micrometastasis in oral squamous cell carcinoma - A retrospective histopathological study

Cervical lymph node metastasis is the most important prognostic factor in squamous cell carcinoma of head and neck. Lymph node prognostic determinants hold immense significance in influencing both patient's survival outcomes and the propensity for recurrence.

To evaluate the diagnostic accuracy of Cyclin D1 and Pan-Cytokeratin (Pan-CK) for the detection of lymph node micrometastasis in oral squamous cell carcinoma (OSCC) tissue sections and re-assess the tumor staging.

Study was executed at Department of Oral and Maxillofacial Pathology and Oral Microbiology, Faculty of Dental Sciences, M.S. Ramaiah University of Applied Sciences, Karnataka, Bangalore, India and study design was In-vitro type.

A total of 30 N₀ lymph node sections of OSCC cases were included in the study. Other than Hematoxylin and Eosin (H&E) and modified PAP (Papanicolaou), immunohistochemistry for Pan-CK and Cyclin D1 were used for identification of micrometastatic deposits.

Pan-CK and Cyclin D1 was helpful in detecting micrometastasis in 16.66% of N₀ lymph nodes which was statistically significant. Based on the results of immunobiomarkers, tumor staging was re-evaluated. Pan-CK and Cyclin D1 showed statistically significant detection of micrometastasis (P = 0.023), whereas Modified PAP did not reach statistical significance (P = 0.083).

Pan-CK and Cyclin D1 were specific in detecting micrometastatic deposits compared H&E and PAP stains. Cyclin D1 immunostaining detects molecular overexpression in tumor cells missed on PAP or H&E, enabling identification of small lymph node deposits and improving staging accuracy and patient management.