HISTOPATHOLOGICAL STUDY OF SOFT TISSUE TUMOURS AND CORRELATION OF HISTOLOGIC GRADE OF SARCOMAS WITH PROLIFERATIVE MARKER KI-67

INTRODUCTION:Soft tissue tumours have diagnostic and therapeutic challenge due to a wide variety of histomorphological patterns. Soft tissue sarcomas are relatively infrequent and constitute less than 1 % of all malignant neoplasms. Immunohistochemical evaluation of Ki-67 is a rapid prognostic tool to assess the cellular proliferation better than mitotic index. METHODS: A prospective study was conducted with a total of 100 cases of soft tissue tumors to analyze the frequency and histomorphology. Soft tissue sarcomas were graded by FNCLCC grading system and were subjected to Ki-67 evaluation. Spearman's Rho and Pearman's correlation coefcients were calculated to determine the correlation between the histologic grade and Ki-67 index. RESULTS: Soft tissue tumours constituted only about 1.3% of all neoplasms. Benign tumours (50%) outnumbered intermediate (11%) and malignant soft tissue tumours (39%). Soft tissue tumours were more common in males (52%) than females (48%) and frequently observed in the sixth decade. The sites of predilection were upper extremities for benign tumours and lower extremities for malignant tumours. Most common benign soft tissue tumour was Neurobroma (19%) followed by Schwannoma (14%). Undifferentiated pleomorphic sarcomas were the most common malignant soft tissue tumour (28%). In FNCLCC grading, most of the sarcomas were grade III (42%). Ki-67 index was low in grade I sarcomas, variable in grade II sarcomas and high in grade III sarcomas. Spearman's rho and Pearman's correlation R values were 0.77 and 0.75 respectively and p value is less than 0.05. CONCLUSION: There is positive correlation between the histologic grade and Ki-67 proliferative index in soft tissue sarcomas. Ki-67 index can be used as an independent prognostic factor to predict the risk of distant metastasis. Prospective evaluation of Ki-67 should be carried out in patients with soft tissue sarcomas for planning adjuvant treatment modalities