FLUORESCENCE OF EXPERIMENTAL ENDOMETRIOSIS IN RABBITS, USING TAMOXIFEN EOSIN ASSOCIATION

A major problem with endometriosis is the detection of microscopic and atypical lesions. An incomplete surgical eradication may lead to recu rrence of the disease. This study aimed to investigate the diagnostic improvement of endometriosis by the use of tamoxifen-eosin induced flu orescence. The experimental study was performed on surgically induced endometriosis in the rabbit. Endometriosis was induced by grafting end ometrium onto the broad ligament in 10 rabbits. After 5 weeks, the flu orescence of excised endometriosis was studied after systemic injectio n of tamoxifen and local application of eosin. Healthy peritoneal samp les served as controls. The fluorescence of endometriotic foci was als o compared with (n = 5) or without (n = 5) tamoxifen. Fluorescence exc itation was carried out using a 150 W filtered lamp connected to an op tical fibre. Fluorescence emission was measured using an optical fibre connected to a spectrofluorometer. Spectral analysis showed a specifi c fluorescence of endometriosis 72 h after systemic injection of tamox ifen and eosin application. This result is explained by binding to oes trogen receptors of tamoxifen which was protonized to form an ionic pa ir with eosin. Histological study of samples from the graft of endomet rial tissue showed that experimental endometriosis had developed in ei ght out of the 10 rabbits. However, the fluorescence was not significa ntly different among the 10 rabbits. This observation was in accordanc e with previous studies in which endometriosis was confirmed by routin e histological techniques or electron microscopy in 70-80% of cases. C onsequently, the fluorescence of the two samples which did not present histological evidence of endometriosis indicates the presence of micr oscopic endometriotic foci. This observation suggests that the diagnos is of endometriosis by the use of tamoxifen-eosin induced fluorescence improves the sensitivity of detection. Identification of microscopic endometriosis will be carefully studied and the consequences of an ear ly identification, which could lead to excessive surgical treatment of this disease, will be evaluated.