Diagnostic and prognostic morphometric features in WHO2003 invasive endometrial stromal tumours

AIMS: The aim of this study was to determine the value of morphometric features in distinguishing mild and moderate atypia and predicting the recurrence of World Health Organization 2003-defined endometrial stromal sarcoma and highly malignant undifferentiated endometrial sarcoma. METHODS AND RESULTS: Nuclear and cytological size, shape and arrangement were morphometrically evaluated in 41 cases with consensus no/mild (n = 38) or moderate (n = 3) atypia. None of the cases showed necrosis. The prognostic value of these features in predicting recurrence was also assessed. Seven features differed. The mean and standard deviation of the nuclear volume and the distance between the nuclei were the best discriminators between the no/mild and moderate atypia, with the maximum of the nuclear volume being a practically and rapidly evaluable alternative. With the use of these features, all mild and moderate atypias were correctly classified. Seven cases recurred. The distance between the nuclei and the percentage of nuclei with one neighbour (assessed with morphometric minimum spanning tree analysis) predicted recurrence. CONCLUSIONS: In invasive endometrial stromal tumours, morphometric features are useful diagnostic support tools for distinguishing mild from moderate atypia and predicting recurrence.