Has anyone had these atypical features with their Metastatic PC???

With your high PSA you need to get a PSMA pet scan as soon as possible. You obviously have metastasis growing somewhere and they’re growing fast as your PSA is rising. They probably can be seen and then zapped with SBRT radiation. Yes, it appears to be an aggressive form of prostate cancer, if you have had a prostatectomy, they might’ve found that your Gleason score was higher.

Why has your doctor not set you up for a PSMA PET scan? I can’t imagine insurance would reject it. You have obviously got aggressive cancer..

No, mediastinal lymphadenopathy is a rare and uncommon issue with prostate cancer. While prostate cancer commonly metastasizes, it typically spreads to the bone and regional pelvic lymph nodes first. The mediastinal lymph nodes, located in the chest, are an unusual site for metastasis.

This is an article that discusses it.
https://pmc.ncbi.nlm.nih.gov/articles/PMC5390533/#:~:text=Prostate%20carcinoma%20is%20the%20second,with%20prostate%20cancer%20%5B2%5D.
I’ve had a weight loss problem in the last few months, Lost 7 pounds in just a couple of days, And my BMI is low normal. I’ve never been heavy. Cachexia is a wasting problem that can occur with prostate cancer and as a result, you have significant loss of weight and loss of appetite. That may not be your problem, but here is more information.
https://my.clevelandclinic.org/health/diseases/cachexia-wasting-syndrome

To clarify:
PSMA PET scans are not readily available in Canada and this scan was thought to be unnecessary after my initial presentation because I was partially responding to doublet therapy ( e.g., PSA dropping, lymph nodes were diminishing in size and I was feeling better, plus a retroperitoneal lymph node needle biopsy was “weakly positive for PSA).

I am not questioning my prostate cancer diagnosis (based on my prostate biopsy) but question if a lymphoma may also be present because:
- extensive metastases to mediastinum, peritoneum, and an adrenal gland, yet not to bone?
- I was hormone resistant from the beginning
And
- lymphoma can cause an elevated PSA

I am unable to post the link because I am a new member but see case report in European Journal of Hematology (2007) entitled “High levels of serum prostate-specific antigen due to PSA producing follicular non-Hodgkin's lymphoma”

FYI - I am no longer losing weight; cachexia is not an issue

After reading your post I found this information which may be helpful to you. BTW, I am not a doctor but have Stage 4 PC, so I am always trying to find the latest information,
1. Metastasis pattern
Prostate cancer usually spreads to bone first, but it can spread to lymph nodes, liver, lungs, and adrenal glands without major bone disease — especially if it’s a more aggressive variant.
Lymphoma more commonly involves mediastinum, peritoneum, and multiple lymph node chains. So his pattern could look like lymphoma, but it isn’t proof.
2. Hormone resistance from the beginning
A small fraction of prostate cancers are resistant to hormone therapy right from the start.
Aggressive variants (like small-cell or neuroendocrine prostate cancer) behave this way too, and they often spread outside bone.
3. PSA and lymphoma
PSA is highly specific to prostate tissue.
Lymphoma itself does not produce PSA.
However, men with both prostate cancer and lymphoma at the same time could theoretically have an elevated PSA because of the prostate cancer.
But an elevated PSA should not be explained by lymphoma alone.
4. What usually happens in cases like this
Doctors sometimes do a repeat biopsy of a metastatic site if the spread pattern is unusual (like no bone disease but lots of visceral/lymph spread). This help confirm whether it’s all prostate cancer, or if there’s another cancer present (like lymphoma).
Imaging (PET/CT with a tracer like PSMA or FDG) can also help distinguish between the two.
In summary:
It is very rare for lymphoma by itself to cause a high PSA — that usually comes only from the prostate. The pattern of spread you have is less typical for prostate cancer, but it can happen, especially with aggressive types. Sometimes doctors will biopsy a lymph node or adrenal lesion just to be certain, so it might be worth asking your care giver your concern

Thanks very much for your reply.

I did have a retroperitoneal lymph node (needle) biopsy in January 2025 that was “weakly positive” for PSA - however the results were not very convincing (I am experienced with immunocytochemistry - the technique used to interpret the biopsy result).

In any event I have agreed to proceed with chemotherapy (Docetaxel) tomorrow and have a repeat CT before my 3rd cycle of chemotherapy (as well as regular bloodwork including PSA Levels). Currently I am having a lot of symptoms (primarily abdominal pain) and need to proceed to chemotherapy as the doublet therapy is not working.

I am just struggling with the atypical features of my prostate cancer presentation.

The night sweats, and weight loss are hallmark signs of lymphoma. Mediastinal lymphadenopathy is atypical for prostate cancer as well. With just 9% of your prostate tissue being involved, despite being a higher risk Gleason 4+3, I am surprised that you have not mentioned having Extra-prostatic Extension ("EPE") or surgical margins. Those are the characteristics that reflect likely spread beyond the prostate. I would seek an internist or hematology oncologist for a lymphoma work-up. Cancers can occur simultaneously, especially if they seem to be occurring in atypical areas of the body. Ninety percent of prostate cancer metastasis are to the bone, but you mention that your bone scan was negative. That is suspicious as well when considering all of the lymph node involvement.
Question: How heavy were you before your weight loss? Being overweight is one contributing factor to Non-Hodgkins Lymphoma (NHL). Unhealthy eating habits and lack of physical exercise are also contributing factors to NHL. Did you have a CBC recently that reflected any anemia? NHL usually includes an anemia as well. Maybe your first symptom was fatigue as well? I have no knowledge of the side effects of medicines that could cause night sweats, but it might be possible. Again, I advise starting with your internist, or...if you have a PPO health plan, go straight to a hematology oncologist. Good luck.

Postrp is giving good if not great advice here. My stage 4 prostate cancer headed straight for the bone and PET scan lit up like a pinball machine then biopsy (bone in lower back) concluded prostate cancer. And although I would have been pleased that it hadn’t spread into my bones, it did, which unfortunately is usually the first place the cancer in the prostate spreads to, so yeah you got good advice and the hematologist is an excellent idea. Ideally an onocologist/hematologist would be diligent. Keep on them like you’ve been doing and stay connected here- these folks know a thing or two about a thing or two!!

Thanks very much for your insights. As you can see I am trying to better understand if I might have two simultaneous cancers.

Despite having in-depth discussions with my medical team (primary care, medical oncologist, radiation oncologist and urologist who specializes in cancer) we have not definitely resolved this question.

Unfortunately I am at a stage (symptoms and disease progression) where we have agreed to pursue chemotherapy tomorrow. Nonetheless, monitoring of future PSA levels and CT scans (or perhaps a PSMA-PET scan) should guide next steps.

FYI - I am a physician - so many of the points you raised regarding lymphoma I have considered (and I do not appear to be someone and increased risk of lymphoma).

Again thanks for your input.

Thanks for your comments and encouragement!