A case of gastrointestinal stromal tumor diagnosed on prostate biopsy.

BACKGROUND: A 56-year-old man initially presented to a local urologist with severe lower urinary tract symptoms and microhematuria. He had a history of hypertension, hyperlipidemia, mild asthma, gastroesophageal reflux disease, erectile dysfunction, and pyeloplasty as a child. Investigations at this time included urinalysis, measurement of serum PSA levels, cystoscopy, urine cytology, and renal ultrasonography. The findings were suggestive of benign prostatic hyperplasia, and the patient received finasteride, tamsulosin, and underwent transurethral needle ablation of the prostate. Four years after the initial presentation, the patient presented to a tertiary institution with worsened symptoms. INVESTIGATIONS: Upon re-presentation, investigations included measurement of serum PSA levels, pelvic CT, transrectal ultrasound-guided prostate biopsy, histological examination of the biopsy specimen and immunohistochemical staining. DIAGNOSIS: Gastrointestinal stromal tumor. MANAGEMENT: Imatinib 400 mg daily followed by surgical resection.