76 yo female with known low grade brain tumor with recent onset of headache.

Non contrast head CT; T1-w MR pre and postcontrast; T2-w spin echo; MR flair; MR susceptibility (SWI)

CT Head pre contrast
1. There is a single mass lesion (consistent with low grade tumor based on history) that has undergone recent hemorrhage necrosis the blood products evident in the dorsal anterior aspect of the tumor, which has released a small amount of blood into the ventricles. There is no secondary hydrocephalus.
2. The mass causes only local mass-effects with effacement of the left frontal horn but not the left cerebral aqueduct.
3. There is age-related ex vacuo ventriculomegaly and frontotemporal atrophic changes.

T1-w MR pre and post contrast
1. The left basifrontal intraaxial mass has contrast enhancement throughout. It has very distinct tumoral margin. The features are those of a low grade paraventricular brain tumor most consistent with low grade ependymoma.
2. There is evidence of some internal hemorrhagic necrosis, which is the source of the minimal intraventricular blood products.

T2-w spin echo
1. The spin echo T2-w sequence confirms the low grade nature of the left basifrontal mass and also indicates there has been intratumoral hemorrhagic necrosis.

MR flair
1. The MR flair also demonstrate changes of internal tumoral hemorrhagic necrosis with minimal intraventricular bleeding.
2. There is no transependymal fluid migration to suggest there is secondary hydrocephalus.

MR susceptibility (SWI)
1.The MR susceptibility clearly demonstrates the full extent of the intratumoral hemorrhagic necrosis as well as demonstrate blood products in the lateral and 4th ventricle.

1. There is a tumoral mass measuring 3.7 x3.0 x 2.8 cm in size with sharply marginated borders that abuts the ependymal surface of the left frontal horn. It is contrast enhancing and does evidence of internal hemorrhagic necrosis. The dorsal hemorrhagic component has bleed minimally into the lateral and 4th ventricles; there is no evidence that this has produce hydrocephalus. The existing ventriculomegaly represents age-related ex vacuo change.

2. All other changes are consistent with the patient's age.

1. Intracranial hemorrhage is not uncommon with metastatic disease and aggressive primary brain tumors. This case demonstrates how even low grade parenchymal tumor can also hemorrhage. However, as in this case, their hemorrhage does not produce a distinct hematoma. It usually results interstitial bleeding. this type of bleeding is often difficult to discern on CT and all MR sequences except MR susceptibility. SWI is exquisitely sensitive to both acute deoxy-Hgb and hemosiderin.

2. This case illustrates how even intratumoral hemorrhagic necrosis can find access to the ventricular CSF, thereby causing acute clinical symptoms (acute onset headache in this case).