Clinical Features and Retroperitoneal Laparoscopic Resection of Adrenal Schwannoma in 19 Patients

Abstract

To explore the diagnostic and therapeutic principles of the rare adrenal schwannoma. We objectively analyzed the detailed clinical data of 19 patients with adrenal schwannoma treated in a large comprehensive medical center in China between January 2009 and March 2014, including general information, clinical manifestations, imaging, adrenal-related endocrine tests, treatment, pathology, and follow-up records. Patients included 16 females and 3 males ranging from 23 to 66 years of age (mean, 48.3 ± 12.6 years), of whom 15 were discovered incidentally. Four patients reported mild abdominal discomfort. Each patient had one unilateral lesion, ranging in diameter from 4.0 to 8.8 cm (mean, 6.2 ± 1.2 cm). Lesions were hypoechoic in 16 patients and cystic-solid in 3 patients. Computed tomography (CT) scanning revealed soft tissue density, mostly with calcifications and clear boundaries. Average values in normal and enhanced CT were 28.7 ± 7.2 Hounsfield units (HU) and 59.7 ± 5.4 HU, respectively. Indicators of adrenal-related endocrine tests were normal, except that catecholamines levels were slightly low in 2 patients with excessively large lesions. All patients underwent uncomplicated retroperitoneal laparoscopic surgery, with subsequent pathology confirmation of adrenal schwannoma. The patients have been followed for 6 months to 4 years, with no recurrence. Our results demonstrate that the onset of adrenal schwannoma is always occult, without typical clinical manifestations and adrenal-related endocrine abnormalities, and the pre-operative diagnosis depends primarily on imaging features of hypoechoic calcifications and mild enhancement. Diagnosis can be confirmed by postoperative pathology. Even with large diameter lesions, retroperitoneal laparoscopic surgery is still the preferred approach, with good prognosis.