Prognostic value of the clinical features and the pathological diagnostic criteria for smooth muscle tumors of the uterus: a morphological and statistical study

There is lack of complete agreement in the literature on the prognostic value of the morphological criteria adopted for diagnosis of malignant cellular smooth muscle tumors of the uterus (CSMTU's). The aims of this study are to correlate with statistical methods the morphological features of 21 consecutive cases of borderline and malignant CMTUs to each other, to age and menopausal status of the patients and to clinical evolution of disease; furthermore, to assess the predictive value of the morphological characteristics considered in the two major classification systems of CMSTUs. The features significantly correlated to progression of disease are: the presence of necrosis and hemorrhage, moderate or severe degrees of atypia and of pleomorphism, cellularity and a mitotic index above 6.28 MF/mm2. Necrosis and hemorrhage, mitotic index, atypia, pleomorphism and cellularity are all significantly and positively correlated to one another. The classes of the two major classification systems of CMSTUs are correlated significantly to outcome of disease, to each other and to most of the aforementioned prognostically meaningful features of CSMTUs. The only morphological feature to be significantly influenced by the age and menopausal status of the patient at diagnosis is the level of mitotic index. Premenopausal women have significantly lower mean mitotic counts than postmenopausal patients regardless of outcome of disease. The length of survival free of disease is significantly associated to menopausal status and is also related to the degree of pleomorphism. The results of this study indicate that the presence of necrosis and hemorrhage, the degree of atypia, pleomorphism and cellularity and the level of mitotic index are all equally expressing the malignant potential of CSMTUs, therefore these features should all be evaluated in the diagnosis of these tumors.