Ganglioneuroma: An Overview

Abstract

Ganglioneuromas (GNs) are rare, benign, well-differentiated, slow-growing tumors that arise from neural crest tissue of the sympathetic nervous system. The effective diagnosis and management of the patient with GN involves the close collaboration of endocrinologists, endocrine surgeons, radiologists, and pathologists. GNs occur most commonly in children and young adults, rarely in adults. They most commonly occur within the posterior mediastinum and retroperitoneum and less commonly in the adrenal medulla. Most GNs are asymptomatic and are discovered incidentally through imaging studies such as ultrasonograpy, computed tomography, and magnetic resonance imaging. Some patients may experience compressive symptoms such as abdominal distention, nonspecific epigastric distress, ptosis, gait disturbance and chest pain. Although GNs are generally considered to be nonsecretory (hormonally inactive), some GNs are endocrinologically active. These tumors may cause some symptoms such as diarrhea, flushing, diaphoresis, cough, abdominal pain, dyspnea, headache, palpitations, tremor, anxiety, hypertension, or virilisation related to secreting hormones. It is difficult to diagnose these tumors precisely by radiologic examination. Radiographically, GNs are relatively homogeneus, encapsulated tumors well-marginated borders. Tumor generally do not invade adjacent structures. However, very rarely, malignant GN has been defined in the literature. Preoperative diagnosis of GNs is often difficult and the diagnosis is usually based on histopathological findings after surgical excision of the tumor. In some cases, fine-needle aspiration biopsy has been reported to be useful in the preoperative diagnosis of GNs. Cytologic diagnosis of GNs requires the experienced cytopathologist to be aware of the cytologic features of these tumors. The defini­tive treatment of choice for GN is usually completed surgical resection. Most tumors can be excised totally. If the tumor is catecholamine secreting, the acute and chronic effects of increased plasma catecholamines should be reversed prior to the surgical excision of the tumor. Combined α-and β-adrenergic blockades are required preoperatively to control high blood pressure and to prevent intraoperative hypertensive crises. Laparoscopic surgery for abdominal GNs may be a better substitute for traditional open surgery due to it is minimal invasive procedure, especially in tumors with a smaller than 6 cm in diameter. On pathologic examination, grossly, GNs are large, well-circumcribed, solid, encapsulated masses of firm consistence with a homogeneous grayish-white cut surface. Microscopically, tumor composed of mature ganglion cells and Schwann’s cells in a fibrous stroma. Immature elements (such as neuroblasts), intermediate cells, cellular atypia, mitotic figures, and necrosis are not features of GN. Overall, patients with GN have a favourable prognosis. The recurrence rate is near zero, and postoperative complications are rare. However, life-long clinical and biochemical follow-up patients with hormone-secreting GNs, adrenal composite pheochromocytoma-GN and metastatic disease is essential.