Pt1b ccRCC in Nov 23 & (pre-existing) Thyroid nodule

Michael7

My father underwent a partial nephrectomy last November. The pathology report showed a pT1b Fuhrmangrade II tumor, measuring 4.2 cm. Right after surgery, another CT scan of the abdomen and thorax was done (also before surgery; everything clear with just a small 4 mm lung nodule), and the radiologist noted a 15 mm hypodense lesion in the thyroid but didn’t give much additional information. From what I’ve read, CT imaging doesn’t provide much insight into thyroid nodules and I'm getting more and more crazy as I go down every rabbit hole as a researcher myself.

Recently, my father asked our family doctor to take another look using ultrasound, and he found 1-2 hypoechoic nodules (likely cold nodules), which supposedly haven’t changed in size. He suggested I see an endocrinologist for further tests, such as a scintigraphy.

Now, after googling, of course, I came across all the worst-case scenarios, including the rare cases of RCCclear cell metastasis to the thyroid. From what I’ve seen, this happens after a significant delay, sometimes even 10 years post-surgery, and only a few hundred cases have been documented.

What concerns me is that studies highlight how difficult it is to diagnose these thyroid metastases in patients with a non-thyroid cancer history—especially RCC, which apparently makes up 50% of the rare thyroid metastasis cases. Even biopsies can be misleading.

Has anyone here experienced something similar or also have (cold) nodules ? I’ve seen cases online where doctors aren’t immediately worried and just keep monitoring the nodules. However, studies also emphasize that someone with a history of RCC should always be checked thoroughly for metastasis and I'm afraid of misdiagnosis. Even afraid that Pt1b is in doubt.

Example for a study:

https://jmedicalcasereports.biomedcentral.com/articles/10.1186/1752-1947-7-265