Male Genital Pathology
On this page
Direct answer
Benign prostatic hyperplasia grows in the transition zone as oestrogen-and-dihydrotestosterone-driven stromal and glandular nodules that compress the urethra, while prostatic adenocarcinoma — over 95 per cent of prostate cancers — arises in the peripheral zone, is graded by the Gleason sum of its two most prevalent patterns, and famously produces osteoblastic bone metastases that raise alkaline phosphatase. Testicular tumours are over 95 per cent germ-cell in origin: seminoma, the commonest in young adults, is cytologically uniform, lymphocyte-studded and radiosensitive, while the non-seminomatous group secretes tumour markers — alpha-fetoprotein from yolk sac elements and human chorionic gonadotrophin from choriocarcinoma. In men over sixty, the commonest testicular tumour is not a germ-cell tumour at all but lymphoma.
What you must remember
- Zones decide: hyperplasia in the transition zone gives obstructive and irritative symptoms with a smoothly enlarged gland; carcinoma in the peripheral zone gives a hard nodule felt posterolaterally on digital rectal examination, often before any urinary symptom.
- BPH management: alpha-1 blockers (tamsulosin) relax the neck quickly; 5-alpha-reductase inhibitors (finasteride) shrink the gland over months by blocking dihydrotestosterone; retention, hydronephrosis, stones and recurrent infection are the complications.
- Gleason score: the two most dominant architectural patterns are each graded 1 to 5 and summed — 3+4 equals 7 fares better than 4+3 equals 7, because the primary pattern is quoted first; scores 8 to 10 are high grade.
- Metastatic pattern: osteoblastic (bone-forming) metastases to lumbar spine and pelvis, with pain, raised alkaline phosphatase and often a high prostate-specific antigen; this blastic pattern distinguishes prostate cancer from the lytic metastases of most other carcinomas.
- Seminoma: peak in the fourth decade, the most common pure germ-cell tumour; sheets of uniform clear cells with lymphocytes and granulomas; radiosensitive and chemo-curable; placental alkaline phosphatase positive.
- Non-seminomatous tumours: yolk sac tumour — the commonest testicular tumour of children, Schiller-Duval bodies, alpha-fetoprotein; choriocarcinoma — human chorionic gonadotrophin, gynaecomastia, earliest haematogenous spread; embryonal carcinoma and teratoma complete the set; mixed tumours are common.
- Cryptorchidism and torsion: undescended testis carries infertility and a several-fold seminoma risk even after orchidopexy; torsion rides on a bell-clapper deformity and threatens the testis within about six hours.
- Penis: squamous cell carcinoma, associated with human papillomavirus 16, chronic balanitis and phimosis, circumcision protective — the commonest penile malignancy in Indian practice.
Two findings, two pathways
The first vignette is a 68-year-old with back pain, and rectal examination finding a stony nodule in the right lateral lobe; prostate-specific antigen is 60. The pathway runs from biopsy (Gleason 4+3, for example) through staging imaging to the bone, where the metastases are sclerotic — the body lays new bone around each tumour focus, hence the rising alkaline phosphatase.
The second vignette is a 26-year-old with a painless, firm testicular enlargement over two months. Testicular cancer is the commonest solid malignancy of young men in this age band, and any painless testicular swelling is a tumour until ultrasound says otherwise. Tumour markers are drawn before surgery — alpha-fetoprotein and human chorionic gonadotrophin, which also stage, prognosticate and later detect recurrence — and the orchidectomy is performed through an inguinal incision, never trans-scrotally, because violating the scrotal skin and lymphatics seeds the inguinal nodes and scatters tumour into a drainage field that would otherwise remain the retroperitoneum. Seminoma then goes to surveillance or radiotherapy; marker-positive non-seminomatous disease goes to chemotherapy tailored to the markers' fall.
Where students slip
The zone answer is the commonest single-mark loss: hyperplasia is transition zone, carcinoma peripheral zone, and candidates reverse them under time pressure. Second, the osteoblastic habit is attributed to other primaries; among common carcinomas, prostate cancer is the archetype of bone-forming metastases — remembering it as "the one that makes bone, not holes" settles several multiple-choice questions. Third, the elderly testicular mass is worked up as germ-cell tumour when lymphoma is the expected answer over sixty.
Frequently asked questions
Which zone of the prostate is involved in hyperplasia versus carcinoma?
Hyperplasia arises in the transition zone surrounding the urethra; carcinoma arises in the peripheral zone, felt as a posterolateral nodule on rectal examination.
What does the Gleason score represent?
The sum of the two most dominant histological patterns, each graded 1 to 5 — a score of 7 written 3+4 behaves better than 4+3 because the higher-grade pattern dominates the latter.
Which metastases are characteristically osteoblastic?
Prostatic adenocarcinoma metastases to spine and pelvis, laying down new bone and raising alkaline phosphatase.
Which tumour markers are secreted by non-seminomatous germ cell tumours?
Alpha-fetoprotein from yolk sac elements and embryonal carcinoma, and human chorionic gonadotrophin from choriocarcinoma and from syncytiotrophoblasts occasionally in seminoma.
Which is the commonest testicular tumour in children and in the elderly?
Yolk sac tumour in children, with Schiller-Duval bodies and alpha-fetoprotein; lymphoma in men over sixty.
Why is the orchidectomy incision inguinal rather than scrotal?
To avoid breaching scrotal skin and lymphatics, which would alter the inguinal nodal field and risk tumour seeding outside the standard retroperitoneal drainage.