Ganglioneuroma is a benign neurogenic tumor arising from the sympathetic chain or adrenal medulla. In the mediastinum, it is most commonly located in the posterior mediastinum (costovertebral sulcus / paravertebral region). It is a well-differentiated, slow-growing, encapsulated mass composed of ganglion cells and mature Schwann cells. On CT, it is a well-defined, homogeneous or mildly heterogeneous, low-to-intermediate density solid mass. Punctate or coarse calcifications are seen in 20-40% of cases. On MRI, it is T1 hypointense/isointense, markedly T2 hyperintense — myxoid stroma explains T2 brightness. Enhancement is late and progressive. Usually asymptomatic, discovered incidentally; large lesions may cause spinal cord compression.
Age Range
10-40
Peak Age
20
Gender
Equal
Prevalence
Uncommon
Ganglioneuroma originates from neural crest cells — it develops as a result of complete differentiation of sympathetic chain ganglia or adrenal medulla chromaffin cells. Histologically, it contains mature ganglion cells, mature Schwann cells, and abundant myxoid/fibrous stroma — this complete maturation determines benign behavior. It is the most mature end of the neuroblastoma (malignant, immature) → ganglioneuroblastoma (mixed) → ganglioneuroma (benign, mature) spectrum, and spontaneous maturation or post-chemotherapy maturation may occur. Myxoid stroma shows T2 hyperintensity on MRI due to high water and glycosaminoglycan content — long T2 relaxation of free water molecules produces high signal. Low-to-intermediate density on CT reflects low cellularity and high water content of myxoid stromal component. Calcifications (20-40%) result from dystrophic calcification or ganglion cell degeneration. Late and progressive enhancement reflects the tumor's low vascularity and slow contrast diffusion through fibrous/myxoid stroma.
Markedly T2 hyperintense, well-defined, elongated solid mass in the posterior mediastinum — brightest T2 signal among neurogenic tumors due to myxoid stroma predominance. Combination with late progressive enhancement and calcification strengthens the diagnosis.
Well-defined, oval or elongated, homogeneous solid mass in the posterior mediastinum (costovertebral sulcus, paravertebral region). Low-to-intermediate density (30-50 HU) — lower than muscle density. Thin capsule may be visible. Grows by displacing adjacent structures (no invasion). Typically 5-10 cm in size.
Report Sentence
A well-defined, homogeneous, low-to-intermediate density solid mass measuring approximately ...x... mm is observed in the paravertebral posterior mediastinum; ganglioneuroma should be primarily considered.
Punctate or coarse calcifications within the mass (20-40% of cases). Calcifications may be scattered or show clustered pattern. This rate is higher than schwannoma and neurofibroma and is important in neurogenic tumor differential.
Report Sentence
Scattered punctate calcifications are observed within the mass, consistent with neurogenic tumor.
Markedly hyperintense signal on T2-weighted sequences — ganglioneuroma shows the brightest T2 signal among posterior mediastinal neurogenic tumors. Homogeneous or mildly heterogeneous hyperintensity. T2 signal is highest in areas where myxoid stroma predominates.
Report Sentence
The mass shows markedly hyperintense signal on T2-weighted sequences, consistent with myxoid stroma-dominant neurogenic tumor.
The mass shows hypointense or isointense signal on T1-weighted sequences (relative to muscle). Homogeneous internal structure. No hemorrhage or fatty component is present — in contrast, hemorrhage may be common in neuroblastoma.
Report Sentence
The mass shows hypointense/isointense signal on T1-weighted sequences with no hemorrhage or fat component detected.
On contrast-enhanced CT, minimal enhancement is seen in the early phase, with progressive enhancement increase in the delayed phase. This late and progressive enhancement pattern is characteristic of ganglioneuroma and reflects the tumor's low vascularity.
Report Sentence
Minimal enhancement in early phase with progressive increase in delayed phase is observed on contrast-enhanced series, consistent with low-vascularity neurogenic tumor.
Intraspinal extension through neural foramen (5-10% of cases) — 'dumbbell' configuration. Neural foramen widening and epidural component within the spinal canal may be observed. This finding is critical for surgical planning.
Report Sentence
Intraspinal extension of the mass through the neural foramen is observed with dumbbell configuration; spinal canal and cord relationship should be evaluated with MRI.
Criteria
Entirely mature ganglion and Schwann cells, no immature neuroblastic elements. No or very low mitotic activity. Ki-67 <1%.
Distinct Features
Homogeneous imaging features, low enhancement, cure with complete surgical resection. Recurrence is extremely rare.
Criteria
Predominantly mature ganglion cells + rare immature neuroblastic foci (less than 5%). Tumor in the process of spontaneous or post-treatment maturation from neuroblastoma/ganglioneuroblastoma.
Distinct Features
More heterogeneous imaging, slightly increased enhancement may occur. Urinary catecholamines may be mildly elevated. Close follow-up after resection is required.
Criteria
Diffuse ganglioneuroma proliferation along the sympathetic chain rather than a single mass. Frequently associated with NF1 (neurofibromatosis type 1) or MEN2B.
Distinct Features
Multiple paravertebral lesions, investigate syndromic findings (NF1: café-au-lait spots, Lisch nodules; MEN2B: medullary thyroid carcinoma, mucosal neuromas). Surgery is more complex.
Distinguishing Feature
Schwannoma shows more intense enhancement and is more heterogeneous on T2 (Antoni A/B patterns). Ganglioneuroma is more homogeneously T2 hyperintense with lower and later enhancement. Calcification is rarer in schwannoma (5-10%).
Distinguishing Feature
Neurofibroma may show 'target sign' on T2 (central low signal + peripheral hyperintensity). This pattern is not seen in ganglioneuroma. Neurofibroma is more commonly associated with NF1 and plexiform variant is diagnostic.
Distinguishing Feature
Neuroblastoma is heterogeneous, invasive, shows early intense enhancement, and calcification is more frequent/coarse (80-90%). Ganglioneuroma is homogeneous, well-defined, shows late enhancement. Neuroblastoma is typically in children under 5 years with elevated catecholamines.
Distinguishing Feature
Lymphoma usually presents as multiple lymphadenopathy in the anterior/middle mediastinum with homogeneous moderate enhancement. Ganglioneuroma is a solitary posterior mediastinal mass. B symptoms (fever, night sweats, weight loss) are common in lymphoma.
Urgency
routineManagement
surgicalBiopsy
Not NeededFollow-up
12-monthGanglioneuroma is a benign tumor and cure is achieved with complete surgical resection — recurrence is extremely rare (0-5%). Imaging follow-up may be applied for small (<4 cm) asymptomatic lesions. Surgery is recommended for symptomatic or growing lesions. Cases with intraspinal extension require neurosurgery-thoracic surgery team approach. Pre-operative urinary catecholamines (VMA, HVA) should be measured — normal values support ganglioneuroma, elevated values suggest neuroblastoma/ganglioneuroblastoma. Syndrome evaluation should be performed in NF1 or MEN2B-associated cases.
Ganglioneuroma is a benign tumor and surgical resection is curative. Most are asymptomatic and discovered incidentally. Recurrence after complete resection is rare. Urine catecholamine levels may be mildly elevated. It may also result from maturation of neuroblastoma/ganglioneuroblastoma.