October 29, 2015
A 6-year-old girl with a history of thoracic mass resection in 2011, now with left proptosis
Metastasic Ganglioneuroblastoma in the Orbit
- Background: Ganglioneuroblastoma is a tumor derived from primordial neural crest cells that form in the sympathetic nervous system. It has inmature and mature cell types and is more frequently found in children.
- Common primary neoplastic sites are adrenal medulla, extra-adrenal retroperitoneum, posterior mediastinum; less common are brain, nasal fossa, neck, ganglion, and pelvis. Bone is the most common site of metastasis.
- Clinical behavior is extremely variable, with some tumors regressing or maturing, while other progress despite aggressive treatment. Neuroblastic tumors may secrete catecholamines such as vanillylmandelic acid (VMA) and homovanillic acid (HVA).
- Prognostic parameters include age, stage, histology, tumor differentiation, mitosis-karyorrhexis index, chromosome 11q, and MYCN oncogene status.3 Children older than 1 year with stage 4 tumors have a 3-year event-free survival rate of 15%. Elevated serum levels of neuron specific enolase (>100 ng/mL) and ferritin (>142 ng/mL) indicate a worse prognosis. Expression of TRK-A, a nerve growth factor, correlates with a favorable outcome.1
- Relevant Clinical Information: Proptosis, periorbital ecchymoses, frontal prominence, pain, weight loss, malaise, irritability, Hutchinson syndrome, Horner syndrome, paraneoplasic syndromes
- Key Diagnostic Features:
- CT scan depicts soft tissue mass with calcifications and variable attenuation values due to areas of necrosis and hemorrhage. Vascular encasement and compression or invasion of adjacent structures may be seen too. Metastasis to the bone may present as sclerotic or lytic lesions and suture widening.
- On MR, lesions are commonly heterogeneous with variable enhancement. Marrow disease appears hypointense on T1WI and hyperintense on T2WI. These findings may differentiate LCH from monostotic fibrous dysplasia (MFD) which presents low signal on T1WI and T2WI (in cases where the fibrous component is predominant).
- DDx: Sclerotic lesions as in this case may be found in fibrous dysplasia, hemangioma, osteosarcoma, osteoblastoma, and lymphoma. The existence of a primary posterior mediastinal, retroperitoneal or adrenal mass points to the diagnosois.
- Treatment Options: Steroids, surgery, chemotherapy, and radiation therapy
