A Giant Lymphatic Cyst of the Adrenal Gland: Report of a Rare Case and Review of the Literature

Lymphatic type of adrenal cysts is most common; however, this type of endothelial cyst is quite rare in excessively large adrenal cysts. A 37-year-old Japanese woman was admitted to our institution with distension of her left flank and the upper quadrant of her abdomen. Abdominal ultrasonography revealed a cystic lesion with a homogenous anechoic texture, and measuring 21 cm in diameter. Computed tomography and magnetic resonance imaging displayed a giant cystic lesion adjacent to the liver, pancreas, kidney, and spleen. The origin of the cyst was not identified. We were not able to make a preoperative diagnosis; therefore, the patient underwent resection of the mass by open laparotomy for therapeutic diagnosis. Intraoperatively, the mass was identified to be cystic and adhered to the left adrenal gland. It was filled with more than 2000 mL of serous brown-red fluid. The content of the cyst contained no atypical cells on cytological examination. The wall of the cyst was composed of a lining of a single layer of lymphatic vessel–derived cells, and the cyst was pathologically classified as a true cyst. No abdominal symptoms were observed and a postoperative radiological work-up showed no evidence of recurrence during a 6-year follow-up period. We describe a case of a patient with a giant lymphatic cyst of the adrenal gland. The preset data suggest that surgeons should decide treatment strategy for large adrenal cysts in consideration of hormonal function, degree of size, and possibility of malignancy.Key words: Giant adrenal cyst, Adrenal gland, Lymphatic cyst, Endothelial cystCystic lesions of the adrenal gland are relatively rare. In 1903, Doran suggested that the first case of an adrenal cyst was described by Greiselius in 1670.¹ In an autopsy series, the incidence of adrenal cysts was reported to be 0.06 to 0.18%.² The actual frequency remains unknown; however, the detection rate of adrenal cysts has risen dramatically due to frequent application of new imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI), which accounts for the identification of approximately 5% of incidental adrenal lesions.³ As patients with small adrenal cysts seldom have any symptom, these cysts are rarely recognized. Small adrenal cysts are usually clinically silent and incidental,⁴ whereas large adrenal cysts—especially greater than 10 cm in diameter—are associated with symptoms because of the mass effect and compression of adjacent organs.⁵ Cases of excessively large adrenal cysts have been reported sporadically, only few dozens of adrenal cysts over 20 cm in diameter have been found.^5–28 Moreover, the lymphatic type of endothelial cyst of the adrenal gland is quite rare in excessively large adrenal cysts.^20,22 Here, we report a rare case of a giant lymphatic cyst of the adrenal gland in a middle-aged woman and summarize the current clinicopathological information on excessively large adrenal cysts and lymphatic type of endothelial cysts.