Transcription factor GATA-4 is a marker of anaplasia in adrenocortical neoplasms of the domestic ferret (Mustela putorius furo)

Adrenocortical neoplasms are a common cause of morbidity in neutered ferrets. Recently we showed that gonadectomized DBA/2J mice develop adrenocortical tumors that express transcription factor GATA-4. Therefore, we screened archival specimens of adrenocortical neoplasms from neutered ferrets to determine whether GATA-4 could be used as a tumor marker in this species. Nuclear immunoreactivity for GATA-4 was evident in 19/22 (86%) of ferret adrenocortical carcinomas and was prominent in areas exhibiting myxoid differentiation. Normal adrenocortical cells lacked GATA-4 expression. Two other markers of adrenocortical tumors in gonadectomized mice, inhibin-a and luteinizing hormone receptor, were coexpressed with GATA-4 in some of the ferret tumors. No GATA-4 expression was observed in three cases of nodular hyperplasia, but patches of anaplastic cells expressing GATA-4 were evident in 7/14 (50%) of tumors classified as adenomas. We conclude that GATA-4 can function as a marker of anaplasia in ferret adrenocortical tumors.