Differential Diagnosis
- Single most likely diagnosis
- Local recurrence of Chromophobe RCC: This is the most likely diagnosis given the patient's history of partial nephrectomy for Chromophobe RCC and the presence of new soft tissue in the left perinephric space adjacent to the surgical bed, as well as a new tiny retroperitoneal nodule in the left lower quadrant.
- Other Likely diagnoses
- Post-surgical scar or granulation tissue: The new soft tissue in the left perinephric space could be a benign post-surgical change, although the presence of a new retroperitoneal nodule makes this less likely.
- Infection or abscess: Although there is no mention of symptoms such as fever or pain, an infectious process could potentially cause new soft tissue or a nodule in the retroperitoneum.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Metastatic disease from another primary cancer: Although the patient has a history of RCC, it is possible that the new findings could represent metastatic disease from a different primary cancer, which would have significant implications for treatment and prognosis.
- Lymphoma: A new retroperitoneal nodule could potentially represent lymphoma, which would require prompt diagnosis and treatment.
- Rare diagnoses
- Sarcoma: A new soft tissue mass in the retroperitoneum could potentially represent a sarcoma, although this is a rare diagnosis.
- Desmoid tumor: A rare, benign but locally aggressive tumor that could present as a new soft tissue mass in the retroperitoneum.