TEACHING POINTS

■ Adrenal pseudocysts are cystic masses often intimately involved with adjacent organs. They can be easily mistaken for benign adrenal cysts, adrenal tumors, or renal cysts.

■ Distinguishing adrenal pseudocysts from other adrenal masses may be difficult and requires radiographic and histopathologic confirmation.

■ The treatment is complete excision when the cyst is symptomatic, enlarged, or suspicious for neoplasm.

■ During evaluation and treatment of abdominal masses, collaborative dialogue between surgeons and radiologists, good communication with patients and family members, collegial collaboration among members of the clinical team, and decision making based on evidence-based review of the surgical literature are all essential for a good outcome.

CASE

A 62-year-old female with diabetes, hypertension, and hepatitis C presented with right upper quadrant pain and stable angina. She reported an increase in her abdominal girth over 2 years and complained of occasional fleeting left flank pain. She denied any changes in bowel or bladder function. She had no history of upper or lower endoscopy and claimed to generally adhere to her medication regimens. On evaluation, she described pain under her right shoulder but reported no history of gallstones, pancreatitis, recent weight loss, constitutional symptoms, or history of trauma. The extended review of systems was negative. Her surgical history included a previous total abdominal hysterectomy with bilateral salpingo-oophorectomy. The physical examination revealed a positive Murphy's sign with peritoneal findings. A large, tender, mobile mass was palpable left of the midline with no obvious bruit or thrill. The rest of the physical examination was nonfocal.

Diagnostic testing Laboratory results were normal for a CBC and electrolyte studies, though mild elevations in hepatic enzymes suggested a cholestatic pattern. Abdominal ultrasonography revealed cholelithiasis with pericholecystic fluid plus hydrops of the gallbladder with a positive sonographic Murphy's sign. Additionally, a large, complex abdominal mass with central necrosis was identified. Contrast-enhanced CT of the abdomen and pelvis showed a 13.3×14.7×17.4-cm mass arising near the distal tail of the pancreas; the mass contained homogenous fluid with scattered calcifications along the periphery (Figure 1).

Laparotomy With a working diagnosis of acute cholecystitis secondary to cholestasis caused by a concurrent symptomatic pancreatic mass, plans were made to perform an abdominal exploration, open cholecystectomy, and pancreatic mass excision. The exploratory laparotomy revealed a large retroperitoneal mass, as expected. The open cholecystectomy was uneventful, with no obstructive choleliths noted in the common bile duct (intraoperative cholangiography was not performed).

The left colon was mobilized, and the retroperitoneal mass was approached carefully. Once the mass was isolated, the posterior pedunculated stalk was the only remaining attachment to free the mass, and therefore an attempt was made to place a right angle clamp around this stalk to ligate these attachments in standard fashion. The tissue was unexpectedly friable and ripped, leading to extensive bleeding. Approximately 1,500 mL of blood immediately filled the operative field; there was no definitive source and there were no consequential hemodynamic manifestations. The mass was freed and removed, and the bleeding vessel was followed down to the left adrenal gland. Intraoperatively, it became clear that the mass had no pancreatic attachments and that the pedunculated stalk perhaps arose from the left adrenal gland.

Once adequate hemostasis was achieved, another re view of the images suggested a hypervascular adrenal source. The patient remained hemodynamically stable through the operative course, further suggesting cystic (adrenal) pathology. The 1.2-kg specimen measured 16.0 °— 14.5 °— 8.0-cm and appeared heterogeneously yellowish gray with a smooth surface. The contents were variegated, with areas of hemorrhage and necrosis (Figure 2). The permanent section microscopic examination revealed no epithelial lining, vascular proliferation with foci of calcification in the peripheral zone, and normal adrenal tissue surrounding the cyst (Figure 3). Postoperatively the patient did well, and she was discharged home on day seven. The final pathology combined with the operative report and re-review of the images confirmed the diagnosis of an adrenal pseudocyst.

DISCUSSION

Histologically, adrenal pseudocysts are cystic masses often intimately involved with adjacent organs. They are typically mistaken for benign adrenal cysts, adrenal tumors, or renal cysts. The treatment is complete excision when the cyst is symptomatic, enlarged, or suspicious for neoplasm.

Adrenal incidentalomas (Table 1) are diagnosed more frequently now that higher resolution imaging technologies are available. Their management is based on functionality and potential for malignancy. Biologically functional tumors are treated with laparoscopic adrenalectomy if they are benign and open adrenalectomy if they are large or potentially malignant. Nonfunctional tumors larger than 6 cm should be considered for excision; masses smaller than 4 cm may be followed closely with serial CT every 6 months for 1 year and then annually should they remain stable. Tumors that are 4 to 6 cm should be considered for adrenalectomy based on the patient's age, imaging characteristics, patient's preference, premorbid state, and fine needle aspiration (FNA) biopsy findings.

Adrenal incidentalomas show no sex predominance. Clinically inapparent tumors are commonly reported in women, reflecting the use of more imaging modalities in this group for making diagnoses. Most adrenal incidentalomas are nonfunctioning and have T2-weighted signal intensity similar to a liver on MRI, but they cannot be differentiated from functional neoplasms based on imaging studies alone. Functioning primary adrenal tumors involving the adrenal cortex typically result in hyperaldosteronism (tumors less than 2 cm in size usually, Conn's syndrome) or hypercortisolism (Cushing's syndrome).

Adrenal pseudocysts are cystic lesions that arise within the adrenal cortex or medulla and are encapsulated by a fibrous wall with no epithelial lining. Although relatively rare, they are the most common cause of adrenal cystic lesions.1 They belong to a class of benign adrenal cysts that includes epithelial, endothelial, and parasitic cysts.2 Adrenal pseudocysts have been reported in 0.064% to 0.18% of the population based on autopsy studies.3 Their etiology is unknown, but they are thought to arise from adrenal vascular malformations, infectious processes, or trauma resulting in intra-adrenal hemorrhage with reorganization and subsequent pseudocyst formation. The vascular origin of these lesions is consistent with the findings of vascular sinusoidal tissue with calcifications.4 Patients affected are predominantly female, with a median age of 41 years.5

Most adrenal pseudocysts are asymptomatic and clinically inconsequential. When large enough, they can produce abdominal pain or chronic back pain, cause symptomatic intra-abdominal masslike effects, or even mimic an acute abdomen.6-8 Some reports indicate that pseudocysts can rupture after trauma, resulting in massive retroperitoneal hemorrhage, gastric outlet obstruction, hypertension, and septicemia.9-12 Large pseudocysts may be palpable and confirmed with imaging studies. The largest pseudocyst reported in the literature measured 30 cm.13 Pseudocysts are often confused with other intra-abdominal cystic lesions, including tumors of the adrenal glands, other benign cystic adrenal lesions, or renal masses.2,14-16

CT of adrenal cysts usually reveals round or oval lowattenuation masses with smooth, thin walls.17 Adrenal pseudocysts are likewise hypodense, have been reported to have rimlike calcification, and if significantly enlarged, can displace the kidneys, pancreas, or colon.18,19 With the advent of higher-resolution CT scanners and better image processing, anatomic relations are now easier to identify. Pancreatic cysts are often more anterior in the peripancreatic region and can be intimately associated with pancreatic tissue.20

Distinguishing adrenal pseudocysts from other benign adrenal masses may be challenging before histopathologic review. The workup for adrenal cystic lesions should include evaluation of the functional status of the cyst with hormonal studies to include the following:

• 24-hour urine and plasma metanephrines/catecholamines (norepinephrine greater than 156 μg/24h, epinephrine greater than 35 μg/24h, and metanephrines greater than 1.8 μg/24h are all diagnostic)

• Dexamethasone suppression test (cortisol greater than 5 μg/dL is diagnostic)

• Plasma aldosterone and renin activity (aldosterone greater than 20 ng/dL and aldosterone:renin ratio greater than 30:1 are diagnostic).

These studies should be followed by surgical excision for symptomatic lesions or those that are greater than 6 cm in size.21 These larger pseudocysts have been associated with adrenal neoplasms, including adrenal carcinoma, adrenal adenomas, and pheochromocytomas.1 Cysts may be removed via an open or laparoscopic approach.3

Once an adrenal mass is identified, gadolinium-enhanced MRI of the abdomen and pelvis followed by metaiodobenzylguanidine (MIBG) scintigraphy should be considered. MIBG concentrates in the adrenergic vesicles with 80% to 90% sensitivity; 123I MIBG has higher sensitivity and specificity than 131I MIBG and allows for the use of single photonemission CT. Nonlocalized findings should be followed up with chest MRI, positron emission tomography, and/ or OctreoScan imaging to help clarify whether operative, surveillance, or conservative therapy is optimum. FNA of an adrenal cyst could be considered, and suspicious metastatic lesions may be biopsied before any surgical intervention. Once operative plans are made, perioperative alpha-blockade and subsequent beta-blockade is paramount to avoid ontable hemodynamic instability.

When a pancreatic mass is suspected, pancreatic protocol CT should be obtained. Dual-phase cross-sectional imaging of the pancreas and liver in arterial and venous phases is used to detect malignant disease. Thin cuts through the pancreas (2.5 mm reconstructed to 1.25 mm) allow for accurate visualization of small cysts and characterization of both morphology and relationships with major vascular structures. Esophagogastroduodenoscopy and endoscopic ultrasonography with FNA of the cyst should be considered in the face of radiographic ambiguity. Aspirations should be evaluated for amylase, lipase, carcinoembryonic antigen, cancer antigen (CA) 19-9, CA 15-3, and neuroendocrine markers when malignancy is suspected. Every effort should be made to achieve a definitive pathologic diagnosis (serous cystadenocarcinoma, solid pseudopapillary tumor, intraductal papillary mucinous neoplasm, or mucinous cystic neoplasm) to establish surgical risk stratification and staging.22 Endoscopic retrograde cholangiopancreatography or a magnetic resonance cholangiopancreatography may be indicated to delineate the difference between a pancreatic cyst and other pancreatic masses.

MEA CULPA OR INCIDENTAL FINDING?

This discussion underscores many salient features in the investigation of suspected abdominal, pancreatic, and adrenal cystic lesions; the need for collaborative dialogue between surgeons and radiologists is just one of them. The primary team should re-review imaging studies before major surgical exploration. In our patient, the radiographic report suggested no adrenal association. Although the surgical house staff may have reviewed the images, they did not conference with their radiology colleagues to confirm this report. This is a key step that should be completed when developing an operative plan and might have better clarified the anatomic relationships preoperatively (Figure 4). No matter what resources are used to treat a patient, the onus of competence and completeness lies with the surgical team.

Informed consent should be obtained once the technical course, expected risks of the procedure, clinical benefits of the operation, typical expected complications of intervening, and reasonable available alternatives are presented to the patient or the durable health care proxy. Occasionally, the best laid plan becomes complicated by unexpected occurrences, as in this case. Resources are available that outline the expected steps to be followed when such intraoperative findings occur. These texts typically encourage prudence and the use of good surgical judgment. Effective and immediate communication with family members intraoperatively or immediately postoperatively is paramount and may avert future litigation. Sometimes, depending on the type of operation (curative versus palliative) and the type of anomaly traversed, the reasonable course may be to abort the procedure or perform a partial ideal operation and revisit the care plan.

In academic medical centers, patients are evaluated and treated by providers with varying funds of knowledge. At tending surgeons, residents, nonphysician clinicians, and students work together in treating surgical patients. Interdisciplinary and collegial collaboration remains the cornerstone to achieving successful outcomes.

Typically, surgical residents are on rotating monthly schedules and may or may not be familiar with all the nuances of a case or clinical finding. The nonphysician clinician, usually a physician assistant on the surgical team, then becomes the default resource. All members of the team should feel encouraged, supported, and unintimidated when challenging a workup, making suggestions, or raising questions during rounds. Such openness can help uncover occult clinical findings and perhaps prevent a catastrophic and/or sentinel event.

Patient management is usually influenced in myriad ways, including by family members, patients themselves, and by the clinical impressions of nonsurgeons. Operative decision making is constantly challenged and thus should be based on evidenced-based review of the surgical literature. Clinical decisions made outside of such a review may be fraught with avoidable morbidity and even mortality. Patient advocacy and the quest for knowledge should remain the sine qua non of an academic medical center, even if it is impossible to achieve 100% of the time. JAAPA

Castigliano Bhamidipati and Matthew Smeds are in the Department of Surgery, State University of New York Upstate Medical University, Syracuse. The authors have indicated no relationships to disclose relating to the content of this article.

REFERENCES

1. Erickson LA, Ricardo RV, Hartman R, Thompson G. Cystic adrenal neoplasms. Cancer. 2004; 101(7):1537-1544.

2. Mohan H, Aggarwal R, Tahlan A, et al. Giant adrenal pseudocyst mimicking a malignant lesion. Can J Surg. 2003;46(6):474.

3. Castillo OA, Litvak JP, Kerkebe M, Urena RD. Laparoscopic management of symptomatic and large adrenal cysts. J Urol. 2005;173(3):915-917.

4. Sezhian N, Rimal D, Suresh G. Adrenal pseudocyst—diagnostic dilemma. Scott Med J. 2005;50(2):81.

5. Medeiros LJ, Lewandrowski KB, Vickery AL Jr. Adrenal pseudocyst: a clinical and pathologic study of eight cases. Hum Pathol. 1989;20(7):660-665.

6. Weinrich M, Pistorius GA, Wagner M, et al. An adrenal pseudocyst as the cause of chronic back pain. Orthopade. 2005;34(12):1263-1266.

7. Papaziogas B, Katsikas B, Psaralexis K, et al. Adrenal pseudocyst presenting as acute abdomen during pregnancy. Acta Chir Belg. 2006;106(6):722-725.

8. Erem C, Celik F, Reis A, et al. Large adrenal pseudocyst presenting with epigastric distress and abdominal distension. Med Princ Pract. 2005;14(4):284-287.

9. Favorito LA, Lott FM, Cavalcante AG. Traumatic rupture of adrenal pseudocyst leading to massive hemorrhage in retroperitoneum. Int Braz J Urol. 2004;30(1):35-36.

10. Pasciak RM, Cook WA. Massive retroperitoneal hemorrhage owing to a ruptured adrenal cyst. J Urol. 1988;139(1):98-100.

11. Karayiannakis AJ, Polychronidis A, Simopoulos C. Giant adrenal pseudocyst presenting with gastric outlet obstruction and hypertension. Urology. 2002;59(6):946viii-946ix.

12. Naess H, Svendsen E, Varhaug JE. Infected pseudocyst of adrenal gland: case report. Eur J Surg. 1991;157(3):237-238.

13. Rao A, Majmudar B, Bumpers H. Giant adrenal pseudocyst. Surgical Rounds. May 2007.

14. Bovio S, Porpiglia F, Bollito E, et al. Adrenal pseudocyst mimicking cancer: a case report. J Endocrinol Invest. 2007;30(3):256-258.

15. Fan F, Pietrow P, Wilson LA, et al. Adrenal pseudocyst: a unique case with adrenal fusion, mimicking a cystic renal mass. Ann Diagn Pathol. 2004;8(2):87-90.

16. Sakamoto I, Nakahara N, Fukuda T, et al. Atypical appearance of adrenal pseudocysts. J Urol. 1994;152(1):150-152.

17. Kawashima A, Sandler CM, Fishman EK, et al. Spectrum of CT findings in nonmalignant disease of the adrenal gland. Radiographics. 1998;18(2):393-412.

18. Sanal HT, Kocaoglu M, Yildirim D, et al. Imaging features of benign adrenal cysts. Eur J Radiol. 2006;60(3):465-469.

19. Habra MA, Feig BW, Waguespack SG. Image in endocrinology: adrenal pseudocyst. J Clin Endocrinol Metab. 2005;90(5):3067-3068.

20. Yang DM, Jung DH, Kim H, et al. Retroperitoneal cystic masses: CT, clinical and pathologic findings and literature review. Radiographics. 2004;24(5):1353-1365.

21. Pradeep PV, Mishra AK, Aggarwal V, et al. Adrenal cysts: an institutional experience. World J Surg. 2006;30(10):1817-1820.

22. Katz MH, Mortenson MM, Wang H, et al. Diagnosis and management of cystic neoplasms of the pancreas: an evidence-based approach. J Am Coll Surg. 2008;207(1):106-120.