Tips to facilitate a preoperative diagnosis of adrenal ganglioneuroma. Report of a challenging experience and review of the literature.

AIM: Ganglioneuroma (GN) is the most uncommon and the most benign tumor among neuroblastic neoplasms, and in 29.7% of cases it finds in an adrenal gland. Usually asymptomatic, this tumor is detected incidentally in the majority of cases. It is generally challenging to obtain a precise diagnosis of adrenal ganglioneuroma (AGN) before surgery. Misdiagnosis rate of AGN on CT and MRI is 64.7% and clinicians and surgeons are often lacking in knowledge of this rare disease. For this reason, we pointed out the clinical, biochemical, radiologic and pathologic features of AGN in an our experience, with the aim to find out if there are some features able to facilitate a preoperative diagnosis. The present article also includes a review of the relevant literature in order to compare laparoscopic versus open adrenalectomy.

CASE REPORT: Right AGN in a 42-year-old woman, in whom preoperative diagnosis was very difficult and only histopathological studies of the surgical specimen established the exact diagnosis. The patient underwent bilateral subcostal laparotomy for a large mass (sized measuring 14.5 x 11.6 x 6.5 cm.) and a right adrenalectomy was performed. Postoperative recovery was uneventful and the patient, at 12-months follow-up, is disease-free and in good health.

DISCUSSION / CONCLUSIONS: Authors stress the importance of interdisciplinary collaboration between surgeons, radiologists and endocrinologists to optimize clinical management and surgical indications. Careful evaluation by endocrine examinations and multiple imaging procedures are necessary to provide a differential diagnosis. Surgeons should consider a diagnosis of AGN in case of: 1) an adrenal incidentaloma; 2) a nonfunctioning tumor with no elevated hormonal secretions, in which compressive symptoms may occur; 3) a homogeneous, encapsulated mass, with well-defined edges, without invasion of nearby structures (no vascular involvement), with presence of calcifications and nonenhanced attenuation of <40 HU on CT; 4) a homogeneous hypointense adrenal mass on T1-weighted MRI, a heterogeneous hyperintense mass on T2-weighted MRI and a poor delayed enhancement on dynamic MRI; a SUV level on PET less than 3.0. Nevertheless, diagnosis of AGN can be extremely challenging and can only be achieved by means of histology. Treatment is complete surgical resection without the need for chemotherapy or radiotherapy. Laparoscopic adrenalectomy is contraindicated in the presence of local infiltration or tumor greater than 12 cm. Even if AGN has an excellent prognosis and recurrences are rare after surgical resections, long-term follow-up is recommended.

KEY WORDS: Adrenal gland, Adrenal ganglioneuroma, Laparoscopic adrenalectomy, Open adrenalectomy.