Hi Leszec,
What a fascinating case.
Indeed it does look like thrombus within the internal jugular vein.
I would love to see a short axis “axial” image or video if you have one.
I can’t think of a condition where there would be a lymph node within the IJV.
But there are plenty of options to consider.
If it is Lemiere syndrome the patient should be unwell with a nasty bacterial pharyngitis or tonsilitis.
How did the patient present?
If it was a lymph node I would suggest it is adjacent to the IJV and may be extrinsically compressing the IJV to create an appearance of something within the IJV.
If it is a lymph node I would expect it to be oval shaped and have an echogenic fatty hilum and a hilarious flow pattern with Doppler. If it is a node I would expect multiple nodes rather than a solitary one.
You can certainly get a DVT style thrombus in the IJV, so this is a possibility.
Then we have a few other options.
With thyroid cancer there can be direct extension via the middle thyroid vein of tumour thrombus into the IJV.
There is also a variety of primary vein wall tumours to consider.
It could be Intravenous pyogenic granuloma (IVPG) which is a subset of lobular capillary haemangioma.
These can certainly be within the IJV.
The wonderful Quanson Sirlyn is going to publish a case study on this topic soon and once it is completed I will upload it to the “articles” tab on this website for you to enjoy.
There is also other vein wall mass possibilities.
Steve.