Brain Masses
Background
- Neoplasm is the biggest concern: ~ 90% of malignant brain masses are metastatic
- Other etiologies: abscess, tumefactive demyelinating lesions, vascular malformations, sometimes other causes of edema (e.g. paraneoplastic)
- Most common metastatic brain tumors: lung, RCC, breast, and melanoma
- Tumors with high bleeding risk: melanoma, thyroid, choriocarcinoma, and RCC
- Gliomas: WHO Grade I-IV, with IV being glioblastoma multiforme (GBM)
- GBM appears as large heterogeneous masses with edema; heterogenous contrast enhancement; can cross the corpus callosum
- Lower grade gliomas, which includes oligodendrogliomas and astroytomas
- Meningioma – usually low grade and either left alone and monitored, but can be symptomatic in which they are resected/radiated
- Ependymoma – uncommon, usually lower grade can cause CSF outflow obstruction
- CNS lymphoma – diffuse WM involvement, with mass effect, restricts diffusion on MRI with prominent contrast enhancement. Can also cross the corpus callosum
- Usually B-cell, initially responds significantly to steroids
Presentation
- A significant number of brain lesions are detected incidentally
- If a pt has a first-time seizure, brain mass needs to be ruled out
- HA (usually constant, severe), seizure and focal neurologic deficits
Evaluation/Management
- Imaging: MRI w/ and w/o contrast provides the most information
- Findings suggesting malignant lesions: marked edema, multifocal lesions, or presence at gray-white junctions
- LP may be indicated if herniation risk is low, particularly if concerned for infection
- Biopsy will ultimately be needed in most cases, which is done through NSGY
Management
- Work up for primary malignancy, CT C/A/P + PET
- Steroids are generally indicated for treatment of edema
- Decadron 10 mg IV to start; then transition to 4mg IV q6h with SSI
- If seizure develops would treat as outlined in seizure section
- Symptomatic tumors need eval by NSGY for resection consideration
- Other options include radiation, which does happen as inpatient but it is rare