Integration of Surgery and Systemic Therapy

to lightly eosinophilic cytoplasm, but 10 tumors had cells with abundant eosinophilic cytoplasm. Large cytoplasmic vacuoles were prominent in 26 tumors. Nuclear atypicality was absent or mild in 54 cases, moderate in 4 cases, and marked in 2 cases. Mitotic rate ranged from less than 1 to 21 per 10 high power fields, with 50 tumors having no or only rare mitoses. Vascular space invasion was present in 11 cases and was prominent in 8. Follow-up of more than five years (average 8.4 years), or until evidence of metastasis was seen, was available for 16 patients. Nine were alive and well with no evidence of disease. Four were alive with disease and three died of disease. The pathologic features that best correlated with a clinically malignant course were as follows: a tumor diameter of 5.0 cm or greater, necrosis, moderate to severe nuclear atypia, vascular invasion and a mitotic rate of more than 5 mitoses per 10 high power fields. Only one of nine benign tumors for which follow-up data of 5 years of more were available had more than one of these features, whereas five of seven malignant tumors had at least three.