Oesophageal metastasis of prostate cancer: a case report

Oesophageal cancer is the seventh leading cause of cancer mortality worldwide. Prostate cancer metastasis to the oesophagus is exceedingly rare. We report an 82-year-old male patient. He presented to the gastroenterology clinic complaining of increased bowel movement frequency from baseline. The patient had a previous history of prostate cancer. Tumour marker analysis revealed markedly elevated levels of carcinoembryonic antigen (CEA), carbohydrate antigen 19 - 9 (CA19-9), and prostate-specific antigen (PSA). Contrast-enhanced magnetic resonance imaging (MRI) of the upper abdomen suggested multiple retroperitoneal lymph node metastases and metastatic lesions in several lumbar vertebrae. Colonoscopy revealed inflammatory changes in the colon, whereas gastroduodenoscopy indicated mucosal lesions in the oesophagus. Haematoxylin and eosin (HE) staining and immunohistochemical analysis (IHC) revealed positive expression of α-methylacyl-CoA racemase (P504S) and androgen receptor (AR), confirming a diagnosis of oesophageal metastasis of prostate cancer. Subcutaneous endocrine therapy with goserelin (3.6 mg every 28 days) was initiated.

Oesophageal metastasis of prostate cancer is extremely rare and typically indicates advanced disease with a poor prognosis. The clinical manifestations are nonspecific and often lead to misdiagnosis. A definitive diagnosis relies on histopathology and immunohistochemical markers, such as PSA and P504S. Clinicians should maintain a high index of suspicion for metastatic prostate cancer in cases of unexplained oesophageal lesions. We hope that this case will increase clinicians' awareness of metastatic oesophageal cancer.