Morphometric analyses of endometriotic tissues to determine their grade of activity

The last revised classification of endometriosis of the American Fertility Society takes the extension of endometriotic lesions and the three macroscopic appearances of this disease into consideration. The aim of this study was to determine whether morphometric analyses are able to describe the grade of activity of endometriotic lesions according to their macroscopic-morphological appearances. Endometriotic samples of 45 patients were analyzed morphometrically using a semiautomatical planimeter. Six different parameters were investigated: the cytoplasmic surface of epithelial cells, the nucleus surface of epithelial cells, the nucleus surface of stromal cells, the gland surface, the gland circumference and the gland diameter. No statistically significant differences (p > 0.05) between the macroscopic appearances of the endometriotic lesions and the six analyzed morphometric parameters were found. The majority of the endometriotic lesions showed median values for the cytoplasmic surface of epithelial cells, the nucleus surface of epithelial cells and the gland surface that did not differ from the median values of all tissues, independently of the macroscopic appearances of these lesions and of the corresponding serum hormonal levels of 17β-estradiol and progesterone that were measured at the time of biopsy (p > 0.05). Our morphometric data showed that the red and so-called 'active' endometriotic lesions did not exhibit different morphometric characteristics from the so-called 'inactive' black or white lesions. We found that white and black lesions showed in some cases higher morphometric values than the mean values, so that these macroscopic appearances of endometriotic lesions cannot be considered as 'burned-out' endometriotic tissues. Therefore, black or white endometriotic lesions also have to be considered as therapeutically relevant, as they cannot be defined as 'inactive' endometriosis.