Challenges of a Complex Rectal Cancer Diagnosis as a Primary Site of Metastatic Prostate Cancer. A Case Report and Literature Review

Prostate cancer (PCa), the most common cancer among men worldwide, remains a complex and challenging diagnosis for clinicians. Difficulties in diagnosing PCa arise from several factors, including, overdiagnosis, time efficient presentation to the clinic, use of insufficiently sensitive screening tools, discomfort testing procedures for instance needle biopsy procedure, and the presence of clinically insignificant PCa patients, leading to unpredictable prognosis [1-3]. Alternatively, pathological findings that determine the primary site of cancer and assess distant metastases are integrated with clinical history, imaging studies, and laboratory tests to distinguish the type and etiology of lesions, thereby establishing a comprehensive diagnosis and therapy. In this article, we present a rare case of prostate cancer metastasizing to an unusual site: the rectum. The patient exhibited typical gastrointestinal symptoms, including constipation, rectal bleeding, and weight loss. Through meticulous investigation, endoscopy, radiological tests, lab tests, and immunohistochemical (IHC) analysis, we confirmed that the ectopic primary tumor was originating from the prostate. This case highlights the importance of considering rare metastatic sites in PCa, as such occurrences can pose diagnostic challenges and lead to delays in treatment. Given the rarity of such cases, further research is needed to improve cancer assessment methods and develop novel, highly specific screening tools that could aid in the early and accurate diagnosis of prostate cancer [4-7]. The challenges in diagnosis range from relatively straightforward cases to those complicated by misdiagnosis, underscoring the need for more effective diagnostic strategies in oncology.