Differential Diagnosis for Elevated PSA after Prostatectomy
- Single most likely diagnosis:
- Prostate cancer recurrence: The significant increase in PSA levels from 34.6 to 51 after prostatectomy and treatment with trimethoprim suggests that the cancer may not have been fully eradicated or has recurred. Trimethoprim is an antibiotic and would not typically affect PSA levels in this manner, indicating the rise is more likely related to the prostate cancer itself.
- Other Likely diagnoses:
- Laboratory error: Although less likely, it's possible that the increase in PSA is due to a laboratory error, where the sample was contaminated or incorrectly processed.
- Residual prostate tissue: After a prostatectomy, small amounts of prostate tissue might remain, potentially leading to elevated PSA levels.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Metastatic prostate cancer: An aggressive form of prostate cancer that has spread to other parts of the body could cause a rapid increase in PSA levels. Early detection and treatment are crucial for improving outcomes.
- Prostate cancer with aggressive variants: Certain aggressive variants of prostate cancer might not respond well to standard treatments, leading to a rapid increase in PSA levels.
- Rare diagnoses:
- Benign conditions affecting PSA: Certain benign conditions, such as prostatitis or benign prostatic hyperplasia (BPH), can cause elevated PSA levels, although this would be less likely given the patient's recent prostatectomy.
- Other cancers: Although rare, other types of cancer could potentially cause elevated PSA levels, such as colorectal or bladder cancer, though these would be uncommon causes of such a significant increase in PSA in this context.