A 15-Year Change of an Adrenal Endothelial Cyst

BACKGROUND Adrenal gland cysts are rare and often occur without any symptoms. Even with advanced imaging modalities, it is still difficult to differentiate a benign adrenal neoplasm from a malignant one. Therefore, it is difficult to arrive at a definitive diagnosis and provide treatment. CASE REPORT We describe a patient with asymptomatic adrenal incidentaloma. The patient was lost to follow-up until 7 years later. On resuming follow-up, an enlarged suprarenal tumor was noted on ultrasound imaging. Magnetic resonance imaging revealed a 6×4 cm tumor mass, and the peripheral part expressed progressive enhancement on dynamic contrast-enhanced images. Laboratory data showed slight hypokalemia, and a complete endocrine assessment was performed, which showed no abnormality. Because malignancy of the adrenal gland remained suspected, a laparoscopic adenectomy was performed. The pathological result showed an adrenal endothelial (vascular) cyst with the formation of thrombi and calcification, without any evidence of malignancy. CONCLUSIONS Adrenal cystic lesions can change with time. Routine imaging studies during follow-up are recommended, and endocrine evaluations should be performed as an initial adrenal tumor work-up. Surgery is the treatment of choice when the cyst is >6 cm in size, malignancy is suspected, or abnormal endocrine activity is present.