An exclusively dopamine secreting paraganglioma in the retroperitoneum: a first clinical case in Korea

Abstract

Exclusively dopamine producing retroperitoneal paragangliomas are extremely rare. We have experienced the first Korean case managed successfully based on the proper evaluation. A 26-year-old female patient came to our attention after the accidental detection of an adrenal mass. She had no symptoms and denied any family history. Laboratory evaluations were normal but serum dopamine (425 ng/L) and 24-hour urine dopamine levels (1,565.3 µg/day) were elevated. She underwent laparoscopic right adrenalectomy. Histopathological diagnosis was a paraganglioma. After operation, dopamine levels in serum and 24-hour urine dropped to 0.09 ng/L and 388.4 µg/day. Dopamine producing paraganglioma elicit no clinical symptoms. Only the dopamine level is elevated in serum and 24-hour urine samples. Surgical resection without using preoperative alpha blockage is the treatment of choice. The prognosis for patients with this tumor tends to be poor because the diagnosis is usually delayed due to lack of symptoms.

Keywords: Adrenal glands; Adrenergic alpha-antagonists; Dopamine; Paraganglioma; Pheochromocytoma.

Fig. 1

Computed tomography scan shows hypervascular mass with dimensions of 4.3 × 3.2 cm on right adrenal gland with early washout enhancing pattern. Mass abuts against inferior vena cava (arrow).

Fig. 2

Magnetic resonance imaging showing 2.8 cm sized mass in right periadrenal area with slightly high signal intensity in T2 weighted image. Mass abuts against and compresses right adrenal gland laterally and inferior vena cava medially (arrow).

Fig. 3

Intraoperative view under videoscope. After careful dissection around tumor, tumor was removed successfully with assistance of surgeon's left hand (arrow).

Fig. 4

Microscopic findings (×40). (A) Hematoxylin/eosin staining revealed peritumoral adipose tissue extension and vascular invasion. Immunohistochemistry results were positive for neuroendocrine markers CD56 (B), synaptophysin (C), and chromogranin (D). The Ki-67 (E) index was less than 1%. S-100 (F) was negative.