Stimulation of a non-functioning pituitary macroadenoma after administration of goserelin acetate for locally advanced prostate cancer causing a sustained elevation in PSA and testosterone.

Long-acting luteinizing hormone-releasing hormone (LHRH) agonists, such as goserelin, have been used for locally advanced and metastatic prostate cancer for many years and are the main forms of androgen deprivation therapy (ADT). Acting on pituitary LHRH receptors, they initially stimulate a transient rise in serum follicle-stimulating hormone (FSH) and LH. Long-term administration of an LHRH analogue will eventually lead to down regulation of LHRH receptors, thus suppressing FSH and LH secretion. This in turn suppresses testosterone production hence achieving and maintaining androgen deprivation. This case highlights the potential anomaly of a sustained elevated serum testosterone in the context of newly diagnosed locally advanced prostate cancer with a co-existing pituitary macroadenoma after administration of LHRH analogues. Alternative methods of androgen deprivation must be considered in such patients.

Metastasis of a cecal adenocarcinoma to the prostate five years after a right hemicolectomy: a case report.

INTRODUCTION: Prostatic metastasis from a primary bowel adenocarcinoma has been only rarely reported in the medical literature. The case reported here is rare in the fact that the primary tumor was from a right-sided bowel adenocarcinoma. It is unusual because initial immunostaining was not fully conclusive, and so a relatively new method of immunostaining, CDX2, was used to ascertain its histopathology. CASE PRESENTATION: We describe the case of a 54-year-old Caucasian man who had a right hemicolectomy for a primary cecal adenocarcinoma, which was completely excised. Following the procedure, he received adjuvant chemotherapy. Computed tomography scans showed no evidence of local recurrence or metastatic disease. Then, five years later, he presented to his general practitioner with urinary symptoms. An abnormal prostate was palpated on digital rectal examination. Trans-rectal prostatic biopsies were performed, which showed colorectal metastases within the prostate gland. This was confirmed with CDX2 immunohistochemistry. There was no further evidence of distant metastases on positron emission tomography-computed tomography scans. CONCLUSIONS: This case demonstrates a rare isolated hematogenous spread to the prostate from a primary cecal adenocarcinoma, several years after definitive treatment and excision. This highlights the importance of accurate immunohistochemistry and imaging in planning further management and treatment.