Adrenal pseudocysts are rare entities consisting of a cystic lesion surrounded by a wall of fibrous connective tissue.1 Although the etiology of adrenal pseudocyst formation is unknown, it is postulated to occur due to malformation and hemorrhage from adrenal veins into the adrenal gland, cystic degeneration of a primary adrenal neoplasm or degeneration of a vascular neoplasm.234 Most adrenal pseudocysts are asymptomatic and require no treatment,5 and they are diagnosed incidentally with the increasing use of imaging modalities. For symptomatic adrenal pseudocysts, treatment options include either percutaneous drainage6 or surgical excision.1257 However, as these cysts are filled with old, hemorrhagic fluid, and it may be difficult to differentiate them from necrotic, malignant neoplasms, surgical excision is preferred.7 Furthermore, with the advent of laparoscopic surgery, most of the symptomatic adrenal pseudocysts can be excised safely via the laparoscopic approach.25 We report a case of a patient with a 7.6 cm-sized right adrenal pseudocyst that was excised laparoscopically.

A 26-year-old lady, presented to our department with a three-month history of abdominal bloating associated with constant, non-radiating right flank discomfort. This was associated with symptoms such as early satiety, although there was no vomiting. She had no other significant medical conditions, and the systematic review was unremarkable. There was no history of trauma to the abdomen. There was also no evidence of any hormonal disorder. She underwent magnetic resonance imaging (MRI) of her abdomen in her home country, which revealed a 7.6×5.7 cm cystic lesion in the right lobe of the liver that was hyperintense on T2 sequencing (Fig. 1A and B). She had previously undergone percutaneous cyst fluid aspiration in her home country prior to seeking treatment in Singapore, but her symptoms had recurred within 2 weeks after the procedure. The cyst fluid cytology during the initial aspiration was benign. Considering the previous cytology findings, with no radiological suspicion of malignancy on the MRI scan, she was offered single incision laparoscopic surgical cyst resection.

A transumbilical approach was employed to gain access into the abdomen using the open Hasson technique.8 A self-made glove port was created to attempt SILS surgery (Fig. 2A). The glove port was made using medium Alexis O wound Protector/Retractor (Applied Medical, Rancho Santa Margarita, CA 92688) with a latex glove modified to accommodate 5 laparoscopic ports including a camera port (Fig. 2B). The camera port was fitted onto the index finger of the glove, and the other four 5mm ports were attached to the other digits. All the working ports were 5 mm in size. A diagnostic laparoscopy was performed, which showed that the cyst was not of hepatic origin. Instead, there was a smooth cystic mass in a retroperitoneal location, posterior to the liver, situated adjacent to the inferior vena cava and attached inferiorly to the right adrenal gland (Fig. 3). Midway through the SILS excision of the cyst, an additional 5 mm port was inserted in the right hypochondriac region to facilitate liver retraction. The cyst was separated and excised using a combination of blunt dissection and LigaSure (Valley Lab, Boulder, CO) without any difficulty. Part of the right adrenal gland was excised together with the cyst as they were adherent. The cyst fluid was found to be brownish, likely indicating previous hemorrhage into the cyst. The cyst fluid was sent for cytology, while the cyst wall was sent for pathological examination. Postoperatively, the patient made an unremarkable recovery and was discharged on the same day. The patient had no postoperative complications and was reassessed 2 months after surgery. The previous abdominal bloating and early satiety had resolved completely at the latest clinical review.

Histologic examination of the cyst wall revealed adrenal cortical tissue enveloping a cyst comprising of a thick rim of dense collagenous fibrous tissue, with no discernible epithelial or endothelial lining (Fig. 4A and B). The cyst wall itself showed scattered calcifications, with degenerative eosinophilic material, cholesterol clefts and hemosiderophages. No granulomata or malignancy was identified. The cytology of the cyst fluid revealed blood and rare inflammatory cells, consistent with previous hemorrhage.

Adrenal pseudocysts are rare. To date, one of the largest recorded adrenal pseudocyst was reported by Davenport et al.9 in a woman measuring up to 22 cm. These pseudocysts are picked up incidentally on imaging or autopsy, or less commonly, they may present with compressive symptoms.67 They are seen more commonly in females.79 In our patient, given the findings suggestive of previous hemorrhage, we postulate that she had experienced previous adrenal hemorrhage, likely to be spontaneous, as there was no history of trauma or infection.1267 The formation of the pseudocyst was likely to be the result of the hematoma enclosed by a fibrotic cavity.67

This case highlights the importance of proper evaluation of a symptomatic cystic lesion in the posterior right hypochondriac region. These cystic masses must be distinguished from other benign or malignant lesions that can originate from the surrounding structures.210 In this patient, the differential diagnoses included a right posterior sector liver cyst, a right renal cyst, a retroperitoneal cyst, or rarely, a bowel duplication cyst in the subhepatic region. As in all adrenal lesions >6 cm, the risk of malignancy increases.211 A single-incision laparoscopic surgery was offered as the cyst did not exhibit any suspicious features on preoperative imaging. However, in order not to compromise any potential oncologic outcomes should the cyst appear suspicious intraoperatively, an anterior surgical approach was undertaken with a low threshold for conversion to conventional laparoscopic or even open surgery.

Since the first laparoscopic adrenalectomy by Gagner et al.12 in 1992, in well selected patients, laparoscopic surgery was shown to reduce blood loss, decrease length of stay with quicker commencement of oral intake and return of bowel function.131415 Single-incision laparoscopic surgery for the adrenal gland, performed either via a retroperitoneoscopic or transabdominal approach, has been gaining popularity,1617181920 with similar outcomes as those of conventional laparoscopic surgery, in addition to improved cosmesis.16 Ishida et al.20 demonstrated that despite the feasibility of single-incision transumbilical laparoscopic adrenal surgery, there were obvious technical difficulties compared to conventional laparoscopy. Hora et al.17 performed single incision laparoscopic adrenalectomies strictly on small tumors with a non-malignant etiology, in their series of 18 cases. In our patient, despite adequate positioning, she had a large floppy liver which was partially obscuring the surgical field. Furthermore, the cyst wall was thin and fragile, and there were no bent instruments, which limited the amount of manipulation possible with the single incision technique. One additional ports was inserted to retract the liver superiorly, in order to achieve optimal exposure of the retrohepatic region to successfully resect the right adrenal pseudocyst. To the best of our knowledge, our case describes the first attempted single-incision laparoscopic surgery of an adrenal pseudocyst and the lessons learned from this experience. A single incision approach might be feasible in a smaller cystic lesion, with or without bent instruments to help to achieve proper triangulation.

In conclusion, adrenal pseudocysts are rare. With advanced imaging techniques, accurate diagnosis is possible and symptomatic adrenal pseudocysts can be safely resected via minimally invasive surgery.