Endometrial polypoid adenomyomatosis in a bitch with ovarian granulosa cell tumour and pyometra

Endometrial polypoid adenomyomatosis in an 8-year-old German shepherd bitch is described. The lesion was associated with ovarian granulosa cell tumour and pyometra; grossly, it consisted of sessile or pedunculated processes with both epithelial and non-epithelial components, in which smooth muscle cells were predominant. The endometrium was diffusely atrophic and showed multifocal squamous metaplasia. The findings are discussed as possible consequences of the functioning ovarian tumour and pyometra, but an involvement of growth factors is also proposed.