Cerebellar ependymoma complicated by post-operative subdural hematoma
Presentation
12-month history of headache.
Patient Data
Large posterior cranial fossa mass centered at the fourth ventricle and extending into the foramen of Luschka on both sides. It is isointense to the grey matter on T2 and homogenous in signal intensity with a lobulated contour. It is effacing the fourth ventricle causing hydrocephalus.
Occipital craniotomy with gas and peripheral high density blood in the resection cavity. Small amount of parenchymal hematoma and surrounding edema in the cerebellar hemispheres causing mass effect. Brain tissue is extending 15mm past the bony margins of the posterior cranial fossa and the brainstem is compressed against the clivus. Large left acute subdural hematoma causing effacement of the left lateral ventricle and third ventricle and midline shift to the right. Right lateral ventricle remains dilated.
There is a left parietal approach ventricular drain traversing the occipital horn of the left lateral ventricle with the tip located in the collapsed temporal horn of the left lateral ventricle.
Conclusion: Large left acute subdural hematoma with midline shift present in the setting of occipital craniotomy.
Case Discussion
This patient underwent an occipital craniotomy for debulking of a large posterior cranial fossa mass. The cerebellar hemispheres became significantly swollen during the surgery and the bone was not able to be replaced despite hyperventilation and mannitol. As a result, the patient had an urgent CT head post-operatively which revealed a large left acute subdural hematoma with midline shift present.
The patient returned to the operating theater for left fronto-temporal-parietal craniotomy with successful evacuation of the hematoma. Left middle meningeal artery was bleeding although it was not established whether this was secondary to elevation of the craniotomy or end the initial case of the hematoma.
Histology
The sections show a moderately cellular tumor, forming prominent perivascular pseudorosettes. The tumor cells form cuffs around blood vessels in a fibrillary background. The tumor cells have mildly enlarged round to elongated nuclei and inconspicuous nucleoli. Very occasional mitoses are seen. There is no endothelial cell hyperplasia or necrosis. Spots of microcalcification are present in the background. The features are those of ependymoma. The Ki-67 index is up to about 5%.
Positive:
- GFAP
- EMA with perinuclear dot pattern
FINAL DIAGNOSIS: Ependymoma (WHO grade II)