Spontaneous occurrence and experimental induction of leiomyoma of the ventral ligament of the oviduct of the hen

Abstract

Leiomyoma of the ventral ligament (VL) of the oviduct is a common tumour of the domestic fowl which occurs in specific pathogen free hens and commercial breeding hens at the end of the first laying season, with prevalence varying from 0 to 60 per cent in different lines and breeds. To investigate the aetiological role of steroid sex hormones in this tumour, subcutaneous implants of diethylstilboestrol (DES), progesterone (P) and DES combined with P (DESP), were administered to chickens at three-week intervals, starting from eight weeks old. DESP produced hyperplasia and leiomyoma of the VL but DES alone produced only hyperplasia. P alone induced neither hyperplasia nor leiomyoma. DESP started to induce leiomyomas within five weeks of the onset of treatment and after 32 weeks of treatment 75 per cent of the DESP group had developed leiomyomas, compared with none in the control group. The results suggest that continuous DESP-treatment can induce hyperplasia and leiomyomas independent of ovarian involvement. The leiomyomas possessed receptors for oestradiol and P. A role of P as a cocardinogen is indicated. These experiments provide the first example of synergism between an oestrogen and progesterone in tumorigenesis in the fowl.