Metabolic activity and clinical features of primary ganglioneuromas

Ganglioneuroma (GN) is considered by most to be a benign tumor of neural crest origin. It may evolve from differentiating neuroblastoma or may be diagnosed as primary ganglioneuroma. The rarity of this tumor and the lack of understanding of its biology often lead to inaccurate diagnosis and treatment.

The authors analyzed clinical features and biologic behavior of primary ganglioneuroma in 49 patients who were registered with but were not part of the national neuroblastoma trials. Data included age and symptoms at diagnosis, gender, tumor localization and size, (123)I-metaiodobenzylguanidine (mIBG) scintigraphy, secretion of catecholamines, histology, treatment, and outcome, whenever available.

Patients with primary ganglioneuroma were significantly older than patients with neuroblastoma. Median age at diagnosis was 79 months compared with 16 months (P < 0.0001). Ganglioneuroma were equally distributed between males and females (1.13:1). A preference of thoracic (41.5%) and abdominal, nonadrenal tumors (37.5%) was observed compared with adrenal GN (21%). At diagnosis, thoracic tumors appeared larger than nonthoracic ones. Local lymph node metastases occurred in two patients. One ganglioneuroma had metastasized to soft tissues. (123)I-mIBG scintigraphy detected mIBG uptake at tumor site in 57% of the GN tumors. Levels of catecholamines in plasma and/or urine were increased in 39%. Slight immaturity of ganglion cells was observed in 93% of all ganglioneuroma tumors. None of the 22 tumors analyzed exhibited MYCN gene alterations. Although 12 patients had macroscopic residuals, no tumor progression or recurrence was observed in a median follow-up of 25 months.

Ganglioneuroma may present with metabolic activity such as increased secretion of catecholamines and/or mIBG uptake. There are no specific diagnostic signs or symptoms discriminating ganglioneuroma and neuroblastoma tumors. Therefore, ganglioneuroma requires tissue investigation for diagnosis. Prognosis after surgical resection without further therapy seems to be excellent.