73M - growing retroperitoneal mass after palliative colon cancer surgery, no biopsy yet, looking for perspective
I'm a 73-year-old male, diabetic. My family is helping me post this. Looking for any perspective, especially from oncologists, radiologists, or anyone who's been through something similar.
Here’s the timeline:
July 2025 - CT showed a large sigmoid colon mass (roughly 7 cm) protruding from the right lateral wall of my sigmoid colon. A few suspicious lymph nodes along the sigmoid mesocolon (6-8 mm). A 7 mm lung nodule in my right lower lobe was flagged as concerning for metastatic malignancy but said could also be unrelated. A secondary 2-3 mm nodule was also partially visualized.
October 2025 - I had gone down from 170 lbs to 130 in less than a year and it wasn’t looking good. I had what they called palliative surgery (I wasn’t doing chemo or radiation at this time). Robotic-assisted low anterior resection with colostomy (Hartmann's procedure). The goal was to relieve a near-obstruction so I could eat again. During surgery, my surgeon found an abscess cavity with pus at the tumor site and noted the rectosigmoid region was tightly adhered. He made a small incision in the retroperitoneum to facilitate removal. He debulked my pelvis and removed as much viable tumor as possible, then cauterized the lateral sidewalls. A lot of this I’m taking directly out of records so apologies if it’s confusing
Pathology came back as moderately differentiated adenocarcinoma, 16.5 cm. Staging pT4a, pN0. Some other notes:
- Radial (circumferential) margin: positive — cancer at the cut edge
- Macroscopic tumor perforation through visceral peritoneum
- Lymphovascular invasion: present
- Venous (large vessel) invasion: present
- Perineural invasion: present
- Tumor budding: intermediate
- 20 lymph nodes removed, all negative (0/20)
- Pathologist noted findings highly suspicious for in-transit metastasis near a peritumoral lymph node but did not meet criteria for upstaged nodal status
- MSI tested on a prior outside biopsy: no loss of expression (microsatellite stable)
- KRAS, BRAF, HER2, NRAS status: unknown / not tested to my knowledge
I did not go with adjuvant chemotherapy or radiation at this time either.
November 2025 – April 2026 — I recovered well, and got to enjoy eating again. Like I said, I had been down to about 130 lbs because of the obstruction and got back up to just under 170. My CEA dropped from 9 to 2 (last checked March 2026). I felt significantly better. No imaging was done during this period and I was able to be myself more or less.
May 2026 — I was hospitalized with fever, originally I’d experienced constipation so my family took me down due to the high fever with that. Blood test came back positive for E. coli but they never found the source. CT without contrast found a moderate-sized RIGHT retroperitoneal hematoma (referenced as 7.6 x 6.4 cm on my next scan), appearing to extend from my psoas muscle, causing hydronephrosis and hydroureter on the right side. They placed a ureteral stent to relieve what they said was apparent pressure on kidney (I think). The mass itself was not sampled or biopsied. The CT showed NO enlarged lymph nodes anywhere. My right lower lobe lung nodule had grown to 11 x 9 mm (from 7 mm in July 2025).
In between this time and June I underwent infusions of antibiotics, and also had the stent in. It was pretty painful, and it was really difficult to sleep. Stent was made of some sort of plastic, which I mention because I’ve had a doctor tell me I’m sensitive to that in the past, not an allergy but something similar where my body reacts.
June 2026 - Follow-up CT without contrast ahead of stent removal (or so I hoped). The mass grew to 10.6 x 8.6 cm (from 7.6 x 6.4 - what they said was significant increase in about 6 weeks). The radiologist changed their language from "hematoma" to "hematoma versus mass." It's described as lobulated and blending into my right iliopsoas muscle. NEW bilateral enlarged lymph nodes are now present — right iliac chain (11x9 mm), left iliac chain (up to 14 mm), right femoral (up to 8 mm). None of these were on the May scan. The report was flagged with a NOTIFY addendum. My lung nodule was not fully covered on this exam. Stent is in place, hydronephrosis has resolved be per doctor.
Follow up visit with urologist - June 2026 - He could feel the mass by pressing on my lower right abdomen. He believes it is colon cancer, not a hematoma. He told me he thinks it is not curable and the long-term prognosis is probably not good. He said several times that he is not an oncologist. He gave me two options: continue what I've been doing, or see an oncologist and have a biopsy. I told him I will likely pursue biopsy so I have that coming up to schedule.
How I'm feeling now:
- My weight has dropped from 170 to about 153 since May - going down again
- I have pain in my right back and right front
- I keep getting low-grade fevers - often will be higher at night
- My white blood cell count may be elevated (not confirmed in a report that I have access to but I thought they said that)
- I have my colostomy and ureteral stent in place still
What my family and I are confused about:
- I improved dramatically for 6 months after a palliative surgery with known residual disease and multiple high-risk features. If cancer was actively growing, why did I recover so much? Or maybe that’s tupical after tumor removal?
- The mass nearly doubled in volume in 6 weeks and bilateral lymph nodes appeared from nothing in the same timeframe. That seems very fast.
- My CEA was “normal” as of March 2026 or back down anyway. but again maybe normal after removal of tumor?
- My original tumor was on the right lateral wall of the sigmoid. The mass is in the right iliac fossa. My surgeon made an incision in the retroperitoneum during the operation. We're not sure if this is a plausible location for recurrence from the positive margin or whether the location argues against it.
- An abscess with pus was documented at the tumor site during my surgery. E. coli was found in my blood in May with no identified source. The mass has never been sampled. I have ongoing low-grade fevers.
- I have not had a biopsy yet and have not seen an oncologist since the surgery back last year.
I’m hoping for any perspective on this picture and posting a few places though also open to advice -does this look like a straightforward recurrence, or does the clinical picture leave room for other explanations? Anything we should be asking that we aren't?
Thank you for reading. and really grateful for this community.