A 68-year-old man from Delhi presents with progressive lower urinary tract symptoms for 8 months: nocturia (×4 per night), weak urinary stream, and incomplete emptying. Digital rectal examination reveals a smooth, firm, enlarged prostate without nodules. PSA is 3.2 ng/mL. Transrectal ultrasound shows uniform glandular enlargement with preserved central echo pattern. Post-void residual urine is 120 mL. What is the most likely histopathological diagnosis?

Explanation

## Diagnosis: Benign Prostatic Hyperplasia (BPH) ### Clinical Presentation **Key Point:** The constellation of lower urinary tract symptoms (LUTS) — nocturia, weak stream, incomplete emptying — combined with smooth, diffuse prostate enlargement on DRE is pathognomonic for BPH. ### Histopathological Features of BPH **High-Yield:** BPH is characterized by: 1. **Stromal proliferation** — smooth muscle and fibrous tissue hyperplasia (dominant component) 2. **Glandular proliferation** — hyperplastic epithelial glands with papillary infoldings 3. **Preserved architecture** — no infiltration or cytologic atypia 4. **Nodular pattern** — typically in transition zone (surrounds urethra) ### Why This Case Is BPH, Not Malignancy | Feature | BPH | Adenocarcinoma | |---------|-----|----------------| | **PSA level** | Often normal or mildly elevated (3–4 ng/mL) | Usually >10 ng/mL in advanced disease | | **DRE findings** | Smooth, symmetric, firm enlargement | Hard, nodular, asymmetric, fixed | | **Ultrasound pattern** | Uniform, preserved central echo | Hypoechoic nodules, disrupted architecture | | **Histology** | Benign glands + stromal hyperplasia | Malignant acini, loss of basal layer, Gleason grade | | **Age of onset** | >50 years (progressive with age) | Variable, but often >65 years | **Clinical Pearl:** Post-void residual >100 mL indicates significant obstruction, typical of BPH. This is NOT a feature of PIN or early adenocarcinoma. ### Pathophysiology of LUTS in BPH ```mermaid flowchart TD A[Stromal & glandular hyperplasia]:::outcome --> B[Increased prostate volume] B --> C[Mechanical obstruction of urethra] C --> D[Increased detrusor pressure] D --> E[Bladder outlet obstruction] E --> F[LUTS: weak stream, nocturia, incomplete emptying]:::outcome D --> G[Detrusor instability] G --> F ``` **Key Point:** The smooth, enlarged prostate with normal PSA and absence of hard nodules rules out adenocarcinoma. PIN and chronic prostatitis would not produce such uniform glandular enlargement or significant post-void residual.