A Case of Metastatic Adrenocortical Carcinoma Diagnosed with Steroidogenic Factor-1 in a Sprague-Dawley Rat

This report describes the morphological and immunohistochemical characteristics of anadrenocortical carcinoma with distant metastasis in a Sprague-Dawley rat. Macroscopically,a single large mass was observed in the adrenal gland, and multiple nodules were noted inthe lung, liver and thyroid. Histologically, the adrenal tumor consisted of a solid growthof eosinophilic round cells with nuclear atypia. Vascular invasion was present, andmultiple metastatic lesions were also observed in the lungs, liver, and mediastinal lymphnodes. Immunohistochemically, the nuclei of these tumor cells were positive forSteroidogenic Factor-1 (SF-1). In the thyroid, tumor cells histologically resemblingadrenal cells were immunohistochemically negative for SF-1 but positive for calcitonin;thus the lesion was diagnosed as thyroid C-cell carcinoma. From these results, the presentcase was diagnosed as adrenocortical carcinoma with distant metastases. SF-1 could be avaluable marker for the differential diagnosis of adrenocortical tumors versus otherendocrine tumors such as C-cell carcinoma.