This broad spectrum of conditions has a variable appearance that at times can mimic malignancy. This discussion features the imaging characteristics of each condition and attempts to highlight the key differentiating factors, when available.
Many tumors have a variety of mimics. We highlight here the most common broad categories of intracranial tumors, namely, high-grade glioma, low-grade glioma, diffuse glioma, lymphoma, and metastases. The mimics list for each of these tumors is by no means exhaustive but is meant to aid in the search for the patient’s true diagnosis.
- Round, peripherally enhancing lesions in regions of heightened vascularity (gray–white interface or basal ganglia)
- Signal is highly variable
- Some will demonstrate focal hemorrhage on MRI-CT imaging
- Breast and bronchogenic carcinoma rarely hemorrhage, but the overall increased prevalence of these tumors makes a hemorrhagic lesion much more likely to be one of these 2 tumors
- Thyroid, teratoma
- Islet cell tumors
- Renal cell carcinoma
- Some will have restricted diffusion
- ~50% are solitary at the time of diagnosis
- Possible nontumor mimics
Contributor: Sean Dodson, MD