2020 Volume 53 Issue 10 Pages 817-825
A 75-year-old man who suffered from dysuria with elevated serum prostate specific antigen (PSA) level was diagnosed as having prostate carcinoma by needle biopsy. Upon further examination, Type 2 rectal carcinoma was found in the anterior wall of the lower rectum concurrently. MRI imaging of the pelvis revealed that the prostate carcinoma was adjacent to the anterior wall of the rectum above the anal canal and also close to the rectal carcinoma. CT revealed multiple lymph node metastases of mesorectal, lateral and inguinal lesions and PET-CT showed metastases to some bones. After one cycle of anti-androgen therapy for Stage D prostate carcinoma, the PSA level was normalized and shrinkage of the metastatic lateral lymph node (LLN) was assessed, followed by laparoscopic abdominoperineal resection for the rectal carcinoma. Pathological findings of the rectal cancer showed well-differentiated adenocarcinoma, pT2, pN0, pStage I and the origin of the mesorectal lymph node (MLN) metastasis was prostate carcinoma with neuroendocrine differentiation. Metastatic prostate carcinoma to the MLN is very rare but it is important to keep this unsuspected pattern of lymphatic spread in mind, especially in case of infiltrative high-risk prostate carcinoma.
