Thread by @TristanRutland7

Brain tumour, adult

PET positive

#Neuropath #Pathtwitter #Pathresidents

Based on the initial images only, what is your first impression?

*metastasis

Another image

Pancytokeratin

PASD (just for @MattieFarzin)

Question:

What type of metastasis do you now favour?

*Papillary

CA-IX

CK7

Naspin-A

TTF-1

⚕️Diagnosis:

🔬Meningothelial meningioma containing metastatic pulmonary carcinoma.

#Pulmpath

Question:

Which of the following tumours is the most likely to metastasize to a meningioma?

1/ Tumour-to-tumour metastasis to meningioma are a rare occurrence with less than 100 cases reported.

2/ Breast appears to be the most common followed by lung (but low numbers).

3/ Breast and meningioma can both express progesterone receptors....

futuremedicine.com/doi/10.2217/cn…

Question:

Criteria (which are quite old!) have been proposed to define true tumour to tumour metastasis (TTM).

Which of the following supports a diagnosis of TTM?

* For metastasizing primary tumour
** Recipient and metastatic tumours

4/ The first criteria were proposed back in 1968.

5a/ Suggested criteria:

✅Evidence of at least 2 primary neoplasms
❌Direct contiguous growth/tumour emboli (excluded).
❌Lymph nodes with lymphoma don’t count!

ncbi.nlm.nih.gov/pmc/articles/P…

5b/ Added (proposed) in 1984

✅Met tumour partly surrounded by recipient tumour.
✅Met tumour primary site must be proven.

pubmed.ncbi.nlm.nih.gov/6330308/

Last question:

Which of the following molecular markers are thought to increase the likelihood of adenocarcinoma metastasizing to a meningioma?

6/ This is a complex area and research is ongoing, however MUC16 may play a role (expressed in adenocarcinomas).

7/ This molecular may bind to mesothelin (in meningiomas) and promote metastasis here.

8/ Lastly a nice recent article is below.

pubmed.ncbi.nlm.nih.gov/34656242/