Cystic schwannoma mimicking adrenal tumor

Cystic lesions of the adrenal gland: our experience over the last 20 years

Cystic lesions of the adrenal gland are uncommon, often presenting with nonspecific clinical and radiologic findings, and are thus underrecognized. They are occasionally associated with malignant neoplasms, which can greatly mimic benign lesions and carry detrimental clinical consequences if misdiagnosed. Here we present our 20-year experience (1992-2012) with these lesions at an academic medical center. Among more than 4500 adrenal gland specimens, 31 cases of adrenal lesions with a predominant cystic component were identified in 30 patients with an age range of 34 to 86 years (median, 55.5 years) and a male/female ratio of 13:17. Macroscopic descriptions, available histologic and immunostain slides, and available radiologic records were reviewed for all included cases. Radiologic studies and gross examination correlated well, and hemorrhage (26 cases; 84%) and encapsulation (25 cases; 81%) appeared to be nonspecific radiologic/gross features shared across histologic subtypes. Microscopic review identified 12 cases (39%) of pseudocysts, 2 cases (6%) of endothelium-derived cysts, and 17 cases (55%) of epithelium-derived cysts. Among these 31 cystic adrenal lesions, 2 cases (6%) were malignant neoplasms (1 epithelioid angiosarcoma, 1 adrenocortical carcinoma). Radiologic impression and histopathologic diagnosis were concordant in 11 (73%) of the 15 cases for which radiologic records were available. This study represents the second largest case series to date on cystic adrenal lesions and presents a comprehensive review on their demographic, clinical, radiologic, and gross and microscopic pathologic features, as well as their differential diagnoses.

Adrenal cystic lesions: a clinicopathological analysis of 25 cases with proposed histogenesis and review of the literature

Adrenal cystic lesions are uncommon and we analyzed clinical and pathologic features of 25 such cases from a single institute over 23 years. There were 16 pseudocysts, eight endothelial cysts, and one epithelial cyst. Seven of eight endothelial cysts were confirmed to be lymphangiomatous by D2-40 immunostaining. We suggest that pseudocysts and endothelial cysts may have different histogenesis. The proposed mesothelial origin of adrenal epithelial cyst cannot be confirmed in our example. Seven adrenal pseudocysts were associated with tumor, including two pheochromocytomas, one neuroblastoma, one adrenal cortical carcinoma, one adrenal cortical adenoma, one myelolipoma, and one schwannoma. The distinction of true cystic lesion from cystic neoplasm is important and requires thorough sampling of the specimens.

Cystic adrenal neoplasms

BACKGROUND

Cystic lesions of the adrenal gland are uncommon and demonstrate a spectrum of histologic changes and may vary from pseudocysts to malignant cystic neoplasms.

METHODS

The authors analyzed a series of primary cystic lesions of the adrenal gland to evaluate the clinicopathologic features and histologic spectrum and to determine features that are helpful in distinguishing benign from malignant cystic adrenal tumors.

RESULTS

A total of 41 cases of macroscopically cystic lesions among patients who underwent surgery at the Mayo Clinic were identified over a 25-year period. Of these 41 cases, 32 were pseudocysts, 8 were endothelial cysts, and 1 was an epithelial cyst. Of the 32 pseudocysts, 6 were associated with adrenal neoplasms, including 2 adrenal cortical carcinomas, 2 adrenal cortical adenomas, and 2 pheochromocytomas. One pheochromocytoma case was identified in association with an endothelial cyst. Both patients with cystic adrenal cortical carcinomas died of disease.

CONCLUSIONS

Adrenal neoplasms, including adrenal cortical carcinomas, may be associated with benign-appearing cysts. Extensive pathologic sampling of resected tissues is important to rule out malignancy in patients with cystic adrenal lesions.

Cystic schwannoma of the orbit

Cystic schwannoma of the orbit is unreported in the world literature. A 54-year-old Caucasian man presented to our clinic with a 5 year history of progressive right-sided proptosis and diplopia. A large paramedian cystic mass displacing the right globe downwards and laterally was demonstrated. From the clinical and radiological features, the presumptive diagnosis of right frontal sinus mucocoele was made. However, the excisional biopsy of the lesion revealed the rare diagnosis of cystic schwannoma, arising from a branch of the first division of the trigeminal nerve. Post-operatively, the patient had a smooth recovery with visual acuity of 20/20 in each eye; full binocular single vision was also re-established. The differential diagnoses of cystic orbital mass, and the radiological and histological findings of the lesion, are described and discussed.

Sonographic features of retroperitoneal neurilemoma

Seven cases of retroperitoneal neurilemoma confirmed by histology had an ultrasound examination. There were 5 women and 2 men with a mean age of 55. Most of the cases (5/7) had a palpable mass clinically. Of the 7 cases, 4 had a mass with cystic degeneration and internal echoes on sonogram, consistent with the macroscopic findings of tumors. The internal echoes represented blood clots and residual tissue (or septa) in cyst. Of the remaining 3 cases, one showed a confluent lobulated mass, the second had a solitary homogeneous mass with small cysts, and the third one, which was the smallest (4 cm x 4 cm x 6 cm), had a hypoechoic and homogeneous pattern. The sonograms of all 7 cases were consistent with the macroscopic features of the tumors. The sonographic pattern of tumor parenchyma is either homogenously hyperechoic or hypoechoic. Because of the cystic degeneration, hemorrhage, and residual tissue of retroperitoneal neurilemoma, the sonographic pattern was variable.