摘要
BACKGROUND Sigmoid colon adenocarcinoma has a high incidence among gastrointestinal tumors,and it very rarely metastasizes to the penis.The literature reports that the prognosis after penile metastasis is generally poor,with a median survival of about 9 mo.Metachronous isolated metastasis to the penis originating from sigmoid colon adenocarcinoma has not been reported so far.Here,we report a case of sigmoid colon adenocarcinoma with isolated penile metastasis occurring 2 years after surgery.The mass was pathologically confirmed as metastatic adenocarcinoma,and oral chemotherapy with capecitabine was given after surgery.The tumor did not recur during the 2-year follow-up period.CASE SUMMARY A 79-year-old man presented to the urology department with"a mass located at the root of the penis since 1 mo".Enhanced computed tomography(CT)examination suggested a 12 mm×10 mm×9 mm nodule at the root of the right penile corpus cavernosum.Cranial,pulmonary,and abdominal CT;and bone scan did not show any tumorigenic lesions.The carcinoembryonic antigen(CEA)level was slightly elevated(6.01 ng/mL,reference value 0-5 ng/mL).The patient had undergone laparoscopic radical sigmoidectomy for sigmoid colon cancer 2 years ago.The postoperative pathology showed moderately differentiated adenocarcinoma of the sigmoid colon,and the stage was PT2N0M0.The penile mass was removed under general anesthesia.The postoperative pathology showed adenocarcinoma,and immunohistochemistry showed CDX2(+),CK20(+),and Villin(+).Based on the medical history,he was diagnosed with penile metastasis from sigmoid colon adenocarcinoma.The CEA level returned to normal(3.34 ng/mL)4 d after surgery.Oral chemotherapy with capecitabine was given subsequently,and tumor recurrence was not found during the 2-year follow-up period.CONCLUSION To our knowledge,this is a rare case of metachronous isolated penile metastasis from sigmoid colon adenocarcinoma.The penis is a potential site of metastasis of colon adenocarcinoma,and the possibility of metastasis should be considered in patients with a history of colon cancer who present with a penile mass.Solitary penile metastasis can be removed surgically,in combination with chemotherapy,and it may have good long-term outcomes.
