Tumor-associated tissue eosinophilia versus tumor associated blood eosinophilia: A ratio of diagnostic importance in oral squamous cell carcinoma

Introduction: Eosinophils are multifunctional granulocytes, which play a pivotal role in health and disease. Tumor Associated Tissue Eosinophilia (TATE) has long been evaluated in the diagnosis and progression of oral squamous cell carcinomas (OSCCs). However, their association with Tumor Associated Blood Eosinophilia (TABE) in OSCCs is still far fetched. We, therefore, attempted to evaluate their individual roles and to achieve a ratio between TATE and TABE in order to signify its usage in objectifying the diagnosis. Materials and Methods: TATE was evaluated using H and E stain per 10 high power fields in 33 previously diagnosed cases of OSCC which were retrieved from department archives. TABE values were achieved from complete blood hemogram reports of patients. TATE/TABE ratio was calculated. All the parameters were clinicopathologically correlated and statistically evaluated using SPSS. Results: TATE represented higher values in well-differentiated squamous cell carcinoma (WDSCC) and poorly differentiated squamous cell carcinoma (PDSCC) and was least in moderately differentiated squamous cell carcinoma (MDSCC), whereas TABE linearly increased from WDSCC to PDSCC. TNM Stage II cases revealed the highest TATE and lowest TABE. TATE/TABE ratio was the highest in WDSCC. Conclusion: Due to the dual nature of eosinophils in early and late carcinogenesis events, evaluation of only TATE might not be conclusive in determining tumor grade. Hence, in a first of its kind attempt, the TATE/TABE ratio may be suitable to achieve a criterion for the determination of tumor grade and may also help to unfold the underlying biologic events.