Thalamic lesion for diagnostic biopsy:Dr Nitin's patient

Friends,
This is 35 year old lady with progressive Left third nerve and right hemiparesis over 2 months. She had obstructive hydrocephalus for which she underwent a shunt.
Her CSF did not reveal any malignant cells.
I would like your opinion regarding how to biopsy this lesion. I am strongly considering lymphoma as possibility. She is not immunocompromised and has no other features of systemic involvement.
Unfortunately, our Stereotactic system is not working and patient cannot afford to move out to some other place.
She has a shunt.
I was considering 3 probable options:
1. Block the shunt, repeat scan after 6 hours and if further dilatation of ventricles, do an endoscopic biopsy. Her right frontal horn is still dilated.
2. Subtemporal approach.
3. Posterior transcallosal approach.

Would like your opinions regarding options.

Nitin Garg

Responses

As you suggested , one could do open biopsy of this lesion through several approaches,including frontal transcortical , transcallosal, subtemporal, parietal transcortical, even with modified Poppen's, approach,
I would rather do an endoscopic biopsy through the frontal horn
of right lateral ventricle
I think right lateral ventricle is not adequately decompressed with the VP shunt , which may need to be followed up

I have a suggestion about the discussion here, I think we should avoid showing the identity of the patients here, esp since this is an open forum

Pramod

Dear Nitin,

A very interesting case indeed. It is rather difficult from the images you have uploaded to ascertain the nature of the lesion. is it T2 dark witha spectro pattern favouring a lymphoma. If so you should strongly consider only a minimally invasive biopsy.Stereotaxy is ideal. I am not sure if an endoscopic approach via the right frontal horn will get you to the lesion. You could consider an image guided (ultrasound) biopsy if you have the apparatus.

Having siad that , I have my reservations on the presumptive diagnosis of a lymphoma. The lesion almost looks extra-axial in some of the cuts. More images would be better to determine the exact location to plan the approach. I may be wrong...but its worth a second look...all the best. Keep us posted on the progress.

ali

Some points reg. nitins case.

1.From limited images sent, to me it is an intrinsic lesion though as ali pointed out the left side thalamic- subthalamic- midbrain component has become exophytic in inferior aspect.

2. Fact that it is present in opp. thalamic region makes extrinsic diagnosis fairly less likely.

3. though lymphoma is a good bet based on periventricular intrinsic location and multiplicity another strong contender would be multifocal high grade glial mass-GBM perhaps. The large size of the left sided lesion in my opinioin makes me think of nonlymphomatous possibility.

4.Reg. approach, this is an ideal case for a)Frame based stereotactic surgery or b)Navigation based frameless stereotaxy.

I would be loathe to pursue craniotomy for just a biopsy, however for circumstances u have mentioned u need to do open surgery, I think post. transcallosal would not be my choice.

for subtemporal too it would require too much retraction of dominant temporal lobe and would risk jeoparadising Labbe'.

If u r comfortable with endoscopy go ahead but 6 hours will not suffice to dilate the ventricles and u would not see the lesion if the foramen monroe is not well dilated to pass thru safely.

Best wishes and keep us updated.

Satish

PS:Maqsood, what happened to your case? Was it not a meningioma?

I agree with pramod that we should maintain anonymity of pt. identity.