Solitary rectal metastasis of prostate cancer resembling primary colorectal cancer

Abstract

Solitary colorectal metastasis of prostate cancer is very rare, but the pathological features can closely resemble a primary colorectal cancer with poorly differentiated adenocarcinoma. Thus, metastasis of prostate cancer should be considered as a differential diagnosis in male patients with colorectal lesion with poorly differentiated adenocarcinoma.

Keywords: colorectal cancer; endoscopy; neoplasia.

Figure 1

Colonoscopy revealed a flat elevated lesion, 15 mm in size, in the rectum (a). Chromoendoscopy with indigo carmine clearly revealed a central depressive area of the lesion (b). Endoscopic biopsy taken from the lesion revealed a poorly differentiated adenocarcinoma (c). Immunohistochemical analysis revealed the tumor cells to be positive for PSA (d).