A case of myxoid adrenocortical carcinoma with extensive lipomatous metaplasia

We report a combination of unusual myxoid change and extensive lipomatous metaplasia of an adrenocortical carcinoma. The patient was a 38-year-old man with hypertension and heart failure. Radiographic examination revealed the presence of a left adrenal tumor, and adrenalectomy was performed. The tumor weighed 380 g and appeared encapsulated. The cut surface was predominantly gelatinous. Histologically, the tumor was composed of atypical round cells with eosinophilic to vacuolated cytoplasm. The tumor was diagnosed as adrenocortical carcinoma. The stroma accumulated copious mucinous material. In addition, individual to nodular mature adipocytes were admixed throughout the tumor. The transition from carcinoma cells to mature adipocytes was recognized. Myxoid change is a very rare phenomenon in adrenocortical carcinoma, and only 10 similar cases have been reported to date. Lipomatous metaplasia is another peculiar feature of adrenocortical lesions that has been reported only in benign conditions. To our knowledge, this is the first reported case of adrenocortical carcinoma with lipomatous metaplasia.