History: 

Status post resection of fourth ventricle ependymoma in 2000 and status post resection of local recurrence 3-2-04.  Status post radiation treatment.  Comparison 3-24-04.

 

Findings:

Note is again made of prior suboccipital craniotomy.  The enhancing soft tissue mass in the left fourth ventricle is stable in size, presently measuring 2.0 cm x 1.5 x 1.3 cm...

 

Impression:

Left fourth ventricle soft tissue mass, suspicious for a residual tumor, not significantly changed in size compared to the prior study.  No evidence of hydrocephalus.  Recommend continued follow up.

Impression:

A mass lesion is identified in the fourth ventricle consistent with the patient's known ependymoma.  There is no significant interval change in the size and configuration of the mass since the previous examination of August 2004.

Impression:

Enhancing fourth ventricle mass slightly larger than on the prior study but no longer demonstrating elevated blood volume.

Findings:

There is evidence of a suboccipital craniectomy.  Artifact in this vicinity suggests that the defect was covered by a metallic mesh.  There is an enhancing lesion that fills the fourth ventricle...

 

Impression:

There is an intraventricular mass within the fourth ventricle, slightly increased in size since the previous examination [of 14 December 2004].  The mass enhances with the contrast agent and also demonstrates elevated blood volume.  The findings are consistent with the history of ependymoma.

Findings:

There is a heterogeneously enhancing mass lesion that occupies much of the fourth ventricle and inferor midline structures of the cerebellum.  The mass is centered slightly to the left of midline.  The enhancement pattern and extent of the abnormality are unchanged [from the 8 March 2005 MRI].  A small amount of edema/gliosis surrounds the lesion, mainly within the left cerebellar hemisphere, also extending into the left cerebellar peduncle.  There is no abnormal enhancement remote to the main lesion...

 

Impression:

There is a mass within the fourth ventricle and inferior midline structures of the cerebellum, stable in size and appearance since the previous examination.  The mass enhances with the contrast agent and demonstrates elevated blood volume, consistent with the history of ependymoma...

Findings:

There is a large mass filling the region of the fourth ventricle.  Maximum diameter is about 3.5 cm.  There appears to be a slight elevation of blood volume at the periphery of the lesion left lateral aspect.

 

There is some evidence to suggest calcification.

 

There is minimal amount of edema in the brain parenchyma surrounding the lesion, in the deep parts of both cerebellar hemispheres.

 

There is mild dilation of the lateral ventricles.  These ventricles have not changed in size appreciably since 6/14/2005.  There is mild T2 signal prolongation adjacent to the frontal horns, but this has not changed and there is no definite evidence to indicate obstructive hydrocephalus.

 

Review of the prior five studies dating back to the earliest available of 10/21/2004 indicates that there has been progressive growth of this tumor with the most rapid growth appearing from 10/21/2004 through 3/8/2005 with relatively less pronounced changes possibly to due the increased rate of sampling as the MR's are being performed more frequently in the recent studies.

 

Impression:

1.  Slight interval enlargement of left ependymoma in the fourth ventricle as compared with 6/14/2005.  Because of the short time interval the change in size is not so obvious, however, comparison of serial examinations demonstrates progressive growth.  Prominence of the supratentorial ventricular system but no definite obstructive hydrocephalus as yet.

2.  Scattered foci of T2 prolongation, stable.

 

Findings:

There is a large nearly 4 cm mass in the fourth ventricle.  It is irregularly enhancing.  There is some extension to the left foramen of Luschka.  The configuration of this enhancing mass is identical in configuration as compared with the last MRI of 7/26/05... There is edema throughout the cerebellum...

 

Impression:

1.  Stable large nearly 4 cm mass in the fourth ventricle consistent with diagnosis of ependymoma.

2.  Obstructive hydrocephalus.  There has been a definite interval change in the size of the ventricular system as compared with the prior MRI of 7/26/05.

 

Diagnosis:  BRAIN, "POSTERIOR FOSSA TUMOR", BIOPSY: EPENDYMOMA, BRAIN, "POSTERIOR FOSSA TUMOR MARGIN", BIOPSY REACTIVE CEREBELLUM. NO TUMOR PRESENT... It is difficult to give this tumor a definitive WHO grading due to the previous radiation therapy. However, a Ki-67 immunohistochemical study is performed which demonstrates a low labeling index... Additional levels are peformed on part 2 labeled "tumor margin". No tumor is identified in this specimen.