Evaluation of Tumour Associated Tissue Eosinophilia and Other Histomorphological Variants as Markers of Metastasis in Squamous Cell Carcinomas

Abstract

Introduction: Tumour Associated Tissue Eosinophilia (TATE), is characterised by the presence of eosinophils as a component of peri and intratumoral inflammatory response. Though lymphocytes are widely recognised in inducing favourable tumour microenvironment, the association with tissue eosinophilia has been infrequently studied. Aim: This study was undertaken to assess the grades of Tumour Associated Tissue Eosinophilia (TATE) and its association with various neoplastic histopathological variables, host tissue inflammatory reaction and the presence or absence of metastases. Materials and Methods: Surgically resected or biopsy specimens (n=148) from patients with squamous cell carcinomas, who had not received any chemotherapy and/ or radiotherapy were included. Those with coexisting tumours, or demonstrating large areas of ulceration and/or necrosis were excluded. TATE was graded from 0 to 4+ depending upon the number of eosinophils/High Power Field (HPF). Tumour morphology, metastases and a variety of other histopathological variables were also observed. Results: High grades of TATE (3+ and 4+) were found in 60.8% of well differentiated squamous cell carcinomas, and were associated with pushing borders (82.3%), intense inflammatory infiltrate (62.7%) and high grade desmoplasia (92.1%). In contrast, low grades of TATE were associated with infiltrating borders (76.2%), low grades of desmoplasia (51.5%) cases and moderate inflammatory infiltrate (59.7%). Tumour metastasized in 45.9% cases of which 89.7% were seen to be associated with low grades of TATE. The association between low grades of TATE and metastases as determined by Chi-square test was highly significant (p<0.001). Conclusion: High grades of TATE are associated with lesser tendency of tumour metastasis and hence may be considered a favourable prognostic marker in squamous cell carcinomas.

Keywords

• favourable
• inflammatory cells
• malignant tumours
• tumour microenvironment