Board Review 3 – Case 7

Neuroradiology board review. This lecture is geared towards the ABR core exam for residents, but it would be useful for review for the ABR certifying exam or certificate of added qualification (CAQ) exam for neuroradiology.

More description and the answer (spoiler!) are seen below the video.

This case shows expansion of the sella on a noncontrast CT, suggesting a long-standing mass. The MRI shows an underlying mass which has areas of hypointensity on T2 and intrinsic hyperintensity on T1 weighted imaging. There is minimal if any enhancement on post-contrast imaging.

The diagnosis is: pituitary adenoma (with hemorrhage)

Pituitary adenomas are common masses of the sella, with about half being non-functional and half hormone secreting. The most common hormone secreted is prolactin, followed by growth hormone. Adenomas can hemorrhage, causing variable imaging appearance.

The primary differential consideration is Rathke cleft cyst, which is more commonly midline, less likely to have blood products and septations, and may have a characteristic peripheral nodule. You can read more about differentiating adenomas and Rathke cleft cysts here.

Board Review 3 – Case 6

Neuroradiology board review. This lecture is geared towards the ABR core exam for residents, but it would be useful for review for the ABR certifying exam or certificate of added qualification (CAQ) exam for neuroradiology.

More description and the answer (spoiler!) are seen below the video.

This case shows a young adult who underwent precocious puberty. There is an expansile, non-enhancing mass in the region of the hypothalamus/tuber cinereum.

The diagnosis is: hypothalamic hamartoma

Hypothalamic hamartomas are disorderly (hamartomatous) collections of neurons in the hypothalamic/suprasellar region. They most commonly occur just behind the optic chiasm and pitutitary infundibulum. Many times, they will present with unusual symptoms like early puberty (most common) or seizure (even with uncommon seizures like laughing “gelastic” seizures or crying seizure).

The differential diagnosis for masses in this region include astrocytoma, craniopharyngioma, and germinoma. The most common overall mass in this region is craniopharygioma, but these commonly enhance avidly, have a mix of solid and cystic regions, and can calcify.

Board Review 3 – Case 5

Neuroradiology board review. This lecture is geared towards the ABR core exam for residents, but it would be useful for review for the ABR certifying exam or certificate of added qualification (CAQ) exam for neuroradiology.

More description and the answer (spoiler!) are seen below the video.

This case shows multiple hemorrhagic and hyperdense masses on a CT. They are predominantly supratentorial, have some edema, and are numerous.

On MRI, the regions have areas of susceptibility (dark T2 signal on GRE), surrounding edema, and enhance avidly.

The diagnosis is: metastatic disease

Intracranial metastases are extremely common and should be considered any time there are multiple masses (although 50% may be solitary). They can have hemorrhage and almost always enhance on post-contrast imaging. The most common locations are supratentorial and at the gray white junction because of the high vascularity there.

Metastases are treated with surgery or radiation. If there is oligometastatic disease (less than 10-20 lesions), stereotactic radiosurgery may be performed. Numerous lesions or leptomeningeal disease can require whole brain radiotherapy.

Board Review 3 – Case 4

Neuroradiology board review. This lecture is geared towards the ABR core exam for residents, but it would be useful for review for the ABR certifying exam or certificate of added qualification (CAQ) exam for neuroradiology.

More description and the answer (spoiler!) are seen below the video.

This case shows an expansile extra-axial mass along the left frontal and parietal calvarium. On CT, it is hyperdense to the adjacent brain and it is causing mass effect and edema in the surrounding brain.On MRI, it is relatively T2 homogenous, appears to be arising outside the brain, and enhances homogenously and avidly.

The diagnosis is: meningioma

Aggressive extra-axial lesions, particularly those causing cortical destruction, have a differential including metastasis, meningioma, lymphoma, and myeloma. You may not be able to differentiate these by imaging.

Meningiomas are the most common brain tumors and most common extra-axial masses. They range in aggressiveness from WHO grade 1 (typical), grade 2 (atypical), and grade 3 (anaplastic), which is determined primarily on histologic features and not imaging criteria. Grade 1 tumors are treated with resection while grades 2 and 3 receive resection followed by radiation therapy.

Board Review 3 – Case 3

Neuroradiology board review. This lecture is geared towards the ABR core exam for residents, but it would be useful for review for the ABR certifying exam or certificate of added qualification (CAQ) exam for neuroradiology.

More description and the answer (spoiler!) are seen below the video.

This case shows a nodular mass along the right frontal calvarium in a patient with pain. It is T2 hyperintense, T1 hypointense, and enhances avidly.

The diagnosis is: skull metastasis

Any mass in the calvarium that has associated osseous destruction is concerning. Benign masses often contain fat (are T1 hyperintense and suppress on T2 fat-saturated imaging) and rarely destroy the cortex. Pain, as was experienced by the patient in this case, is also a concerning feature.

Any patient with a concerning calvarial mass but no history of malignancy should probably be evaluated for metastatic disease. While the evaluation may vary by institution, it will most commonly consist of a whole body PET/CT or CT of the chest, abdomen, and pelvis.

Board Review 3 – Case 2

Neuroradiology board review. This lecture is geared towards the ABR core exam for residents, but it would be useful for review for the ABR certifying exam or certificate of added qualification (CAQ) exam for neuroradiology.

More description and the answer (spoiler!) are seen below the video.

This case shows a nodular multifocal mass along the walls of the ventricles. It is relatively low intensity on T2, hyperintense on DWI, and enhances avidly with a nodular solid pattern.

The diagnosis is: CNS lymphoma

Primary CNS lymphoma is a B-cell malignancy with relatively low incidence but overall poor outcomes. It is more common in immunocompromised or HIV patients. The most common locations are in periventricular white matter, the basal ganglia, and the corpus callosum. Solid nodular enhancement, T2 hypointensity, and low ADC values are characteristic. In fact, lower ADC values are associated with a poorer prognosis.

HIV and immunocompromised patients are more likely to have variable enhancement patterns, such as rim enhancement with central necrosis.

Board Review 3 – Case 1

Neuroradiology board review. This lecture is geared towards the ABR core exam for residents, but it would be useful for review for the ABR certifying exam or certificate of added qualification (CAQ) exam for neuroradiology.

More description and the answer (spoiler!) are seen below the video.

This case shows a minimally enhancing mass along the anterior part of the septum pellucidum. This patient also has hydrocephalus which may be contributing to the symptoms.

The diagnosis is: subependymoma

Masses in the ventricles and along the septum pellucidum have a broad differential diagnosis, but in this case subependymoma is the best fit because it is a relatively indolent appearing, minimally enhancing mass.

The other possibilities include:

• ependymoma – usually has more avid enhancement
• central neurocytoma – also usually has more enhancement
• subependymal giant cell tumor (SEGT) – possible, but more likely in a patient with tuberous sclerosis
• choroid plexus tumor – more commonly enhances avidly
• hemangioblastoma – often will have flow voids
• metastatic disease – also more avid enhancement

If you see a minimally enhancing ependymal/subependymal tumor, think about subependymoma.