Histopathological grading in soft-tissue tumours. Relation to survival in 261 surgically treated patients.

A system for histopathological grading of malignancy in soft-tissue sarcoma is described in detail, and the importance of the grade of tumour in predicting survival is demonstrated in a consecutive series of 261 surgically treated patients with sarcoma of the somatic soft tissue. Mitosis index is the main discriminating criterion. Delay in fixation, for instance in large specimens, may cause an artificially low mitosis index calling for the need of other criteria, too, reflecting grade of malignancy: cellularity, anaplasia, number of pycnotic and/or fragmented nuclei. There is a significant difference in survival between the three grades, 10 years survival with surgical treatment alone is 97%, 57% and 29% for grades 1, 2 and 3 respectively.