Schwannoma
Epidemiology
- Most common of all neural tumors
- The most common causes of posterior mediastinal masses in adults are neurogenic tumors, accounting for more than 80%
- Neurogenic tumors of the mediastinum comprise 20% of adult and more than 35% of pediatric mediastinal tumors
- Age: most commonly develop in patients in their 30s or 40s
- Sex: equal sex predilection
Physiology
- Benign lung neoplasm
- Arise from nerve root (and contain only Schwann cells)
- Typically arise from sympathetic and parasympathetic ganglia or from peripheral nerves of the spinal ganglia
- They are most commonly located posteriorly
- Rarely arise from vagus or phrenic nerves
Pathology
- Composed of Schwann cells with surrounding reticular tissue
Diagnosis
- CXR/Chest CT Pattern:
- Solitary Lung Nodule (usually well-defined):
- Location: no lobar predilection
- Calcification: rare
- Cavitation: none
- Posterior Mediastinal Mass:
- Well rounded circumscribed mass, usually located contiguous to the vertebral body in the intercostal or paravertebral spaces
- Sometimes an hourglass shaped lesion can develop
- MRI: T1-weighted magnetic resonance imaging is helpful in determining vertebral column and spinal cord involvement
Clinical Presentations:
- Lung Nodule (see [[Lung Nodule or Mass]])
- Posterior Mediastinal Mass (see [[Mediastinal Mass]])
- Almost always benign (but may be malignant in some cases)
- Asymptomatic: often
- Chest Wall Pain:
- Cough:
- Horner’s Syndrome: in rare instances
- Neurologic Symptoms: parasthesias in UE consistent with a radiculopathy
Treatment
- Surgical resection via thoracoscopy or thoracotomy: treatment of choice
References