Low PSA but high-grade prostate cancer presenting as a bladder-neck mass in a young patient with refractory bladder outlet obstruction.

Prostate cancer most commonly originates from the peripheral zone and is typically detected by elevated prostate-specific antigen (PSA) levels. We present a 42-year-old man with progressive lower urinary tract symptoms and a PSA level within the normal range (1.45 ng/mL). Uroflowmetry demonstrated significant bladder outlet obstruction (Qmax 8 mL/s). Cystoscopy revealed a 2 cm bladder-neck mass, which was resected transurethrally. Histopathology confirmed prostatic adenocarcinoma with a Gleason score of 5 + 4 = 9. Multiparametric MRI showed a PI-RADS 4 lesion, and PSMA PET-CT demonstrated no metastasis. This case highlights that aggressive prostate cancer may present with normal PSA and mimic benign obstruction.