PA28.1-6 | Male Genital Tract — Glossary

Enzyme (type 2 predominant in prostate stroma) that converts testosterone to the more potent dihydrotestosterone (DHT); inhibited by finasteride and dutasteride

A fetal liver glycoprotein that serves as a serum tumor marker for yolk sac tumor and embryonal carcinoma components; never elevated in pure seminoma — an elevated AFP forces reclassification to NSGCT.

Alpha-methylacyl-CoA racemase; a metabolic enzyme overexpressed in prostatic adenocarcinoma; used as a positive IHC marker to diagnose carcinoma in needle biopsies

Reduction of testosterone to castrate levels by bilateral orchidectomy or medical means (LHRH agonists/antagonists); cornerstone of treatment for metastatic prostate cancer

The outer layer of prostatic ductal and acinar epithelium composed of small, flattened p63/CK5/6-positive cells; present in BPH and normal glands, absent in prostatic adenocarcinoma

A valveless perivertebral venous system that communicates directly with pelvic and prostatic veins; the preferred haematogenous route for prostate cancer metastasis to the lumbar spine

The standard cisplatin-based regimen for advanced testicular GCTs consisting of Bleomycin, Etoposide, and cisPlatin; both seminoma and NSGCT are sensitive, though seminoma is additionally radiosensitive.

Squamous carcinoma in situ (PeIN) occurring on the keratinized skin of the penile shaft; appears as a thickened hyperkeratotic grayish-white plaque; ~10% risk of progression to invasive SCC.

Multiple small red-brown papules on the penile shaft or glans, histologically identical to PeIN but with lower malignant potential in immunocompetent young adults; associated with HPV 16/18.

Disease progression despite castrate levels of testosterone; results from AR gene amplification, activating mutations, or splice variants (AR-V7); marks a critical clinical threshold in prostate cancer management

A highly aggressive GCT recapitulating placental trophoblast with a biphasic pattern of cytotrophoblasts and syncytiotrophoblasts; characterised by marked β-hCG elevation and early hematogenous metastasis.

The rarest and most aggressive testicular GCT; characterized by biphasic proliferation of cytotrophoblasts and syncytiotrophoblasts; produces β-hCG; extensive hemorrhage and necrosis; early haematogenous spread.

The most cephalad deep inguinal lymph node, located at the femoral ring; serves as a sentinel for pelvic node involvement in penile carcinoma; assessed by FNA or biopsy before pelvic lymph node dissection.

Benign papillary genital wart caused by HPV 6/11; characterized by koilocytosis, papillary fronds with fibrovascular cores, and no dysplasia.

Laminated, eosinophilic concentric bodies found in prostatic gland lumina; formed from condensed secretions; benign, increase with age, not pathological

Failure of one or both testes to descend fully into the scrotum; the strongest known risk factor for testicular GCT, conferring 3–5-fold increased risk in the affected testis.

Reactive proliferation of fibrous connective tissue stroma surrounding invasive carcinoma nests; reflects tumor-stroma interaction; provides the 'firm/indurated' texture on palpation.

The active intracellular androgen in the prostate; formed from testosterone by 5α-reductase type 2; drives both normal prostatic growth and BPH; binds the androgen receptor with ~5× greater affinity than testosterone

Viral proteins encoded by high-risk HPV (types 16, 18); E6 binds and degrades p53 (disabling apoptosis); E7 binds and inactivates Rb (driving cell cycle progression); together they initiate malignant transformation.

A highly aggressive NSGCT composed of large pleomorphic cells resembling early embryonic cells, with hemorrhage and necrosis; the most undifferentiated NSGCT after choriocarcinoma.

Squamous carcinoma in situ (PeIN) occurring on the non-keratinized mucosa of the glans or inner prepuce; appears as a bright red, velvety, moist plaque; higher malignant potential than Bowen disease (~10–30%).

The precursor lesion of all invasive testicular GCTs (except spermatocytic tumor); consists of atypical germ cells within seminiferous tubules expressing OCT3/4 and PLAP, with i(12p).

A neoplasm arising from pluripotent germ cells in the testis (or ovary/extragonadal sites); accounts for ~95% of testicular tumors and includes seminoma and all non-seminomatous subtypes.

Histological grading system for prostate adenocarcinoma based on glandular architecture and degree of differentiation, scored on patterns 1–5; the primary and secondary patterns are summed to give the Gleason score (6–10 in clinical use)

Both score 7 but carry different prognoses: Gleason 3+4 (Grade Group 2) has better outcomes than Gleason 4+3 (Grade Group 3) because the primary pattern (first number) has greater prognostic weight.

A 5-tier prognostic grouping of prostatic adenocarcinoma based on Gleason score: Group 1 (score ≤6) through Group 5 (score 9–10); introduced to address limitations of the Gleason score scale.

Prostatitis characterised by epithelioid macrophage granulomas; causes include M. tuberculosis (caseating), non-specific (non-caseating, reaction to extravasated secretions), and BCG-induced (after intravesical therapy)

A paradoxical enlargement of a residual retroperitoneal or mediastinal mass during or after chemotherapy with falling serum markers, representing chemotherapy-induced differentiation to mature teratoma; requires surgical resection.

A cytologically malignant intraepithelial proliferation with intact basal cell layer; the recognised precursor lesion of prostatic adenocarcinoma; AMACR positive, basal cells positive

High-molecular-weight cytokeratin; expressed in basal cells of normal and hyperplastic prostate glands; ABSENT in prostatic adenocarcinoma; used with p63 to confirm basal cell layer presence (BPH) or absence (carcinoma).

The older term for GCNIS (germ cell neoplasia in situ); replaced by GCNIS in current WHO classification but may appear in older textbooks.

The in-situ precursor of all invasive testicular germ cell tumors (except spermatocytic tumor); appears as enlarged atypical germ cells within seminiferous tubules; also called carcinoma in situ of the testis.

A validated 7-question self-administered questionnaire quantifying LUTS severity (0–35 scale); used to gauge BPH impact and treatment response

A structural chromosomal abnormality in which both arms of chromosome 12 consist of duplicated short arms (12p); found in ~80% of testicular GCTs and is the hallmark genomic alteration driving tumor progression.

A 5-tier prognostic classification (GG1–5) replacing the old Gleason 6–10 scale to reduce confusion; GG1=Gleason 3+3=6 (best) through GG5=Gleason 9–10 (worst)

Concentric whorls of squamoid cells with central laminated keratin within a squamous cell carcinoma nest; also called squamous or epithelial pearl; hallmark of well-differentiated keratinizing SCC.

A squamous epithelial cell showing the cytopathic effect of HPV infection: perinuclear cytoplasmic clearing (halo) with a dark, wrinkled (raisinoid) nucleus. Hallmark of condyloma acuminatum.

A non-specific serum marker that correlates with tumor bulk and cell turnover in testicular GCTs; used in the IGCCCG prognostic classification for advanced disease.

The most common sex cord-stromal tumor of the testis, arising from testosterone-producing Leydig cells; characterised histologically by Reinke crystalloids and clinically by precocious puberty (in boys) or gynecomastia (in adults).

Symptoms arising from the bladder and urethra divided into obstructive (voiding: hesitancy, weak stream, straining) and irritative (storage: frequency, urgency, nocturia)

Tumor cells within lymphatic or vascular channels in pathological specimens; in penile SCC, LVI presence upstages T1 tumors from T1a to T1b and indicates higher risk of nodal metastasis.

Anatomical subdivision of the prostate into transition zone (periurethral), central zone (around ejaculatory ducts), peripheral zone (posterior, palpable), and anterior fibromuscular stroma

Diagnostic localisation test for prostatitis: sequential collection of voided urine fractions and expressed prostatic secretions to localise infection to urethra vs bladder vs prostate vs seminal vesicles

A testicular GCT containing two or more distinct histological subtypes within the same tumor; the most common NSGCT subtype, with clinical behavior dictated by the most aggressive component present.

MRI protocol combining T2-weighted, diffusion-weighted (DWI), and dynamic contrast-enhanced sequences for localising and staging prostate cancer; scores reported as PI-RADS 1–5

An umbrella term for all testicular GCTs that are not histologically seminoma, including embryonal carcinoma, yolk sac tumor, choriocarcinoma, teratoma, and mixed tumors; generally managed with cisplatin-based chemotherapy.

A transcription factor maintaining pluripotency in embryonic stem cells; constitutively expressed in GCNIS, seminoma, and embryonal carcinoma — a key immunohistochemical marker of primitive GCTs.

Bone metastasis characterised by increased bone formation rather than destruction; appears dense/sclerotic on X-ray and isotope bone scan; characteristic of prostate cancer (via endothelin-1 secretion), contrasting with osteolytic lesions of most other carcinomas

Retroperitoneal lymph nodes located at the L1–L2 vertebral level along the aorta; the primary lymphatic drainage site of the testis and the first nodal station of metastasis for most testicular GCTs.

Full-thickness or near-full-thickness squamous dysplasia of the penile epithelium without stromal invasion; caused by HPV 16/18; includes Bowen disease, erythroplasia of Queyrat, and bowenoid papulosis.

Extension of malignant glands along nerve sheaths within the prostate; a diagnostic criterion for adenocarcinoma on needle biopsy and an indicator of potential extracapsular spread

Infiltration of tumor cells around or within nerve sheaths in the stroma; in prostatic biopsies, virtually diagnostic of adenocarcinoma; indicates a route for extraprostatic spread.

The largest zone of the prostate (~70% of volume), located posterolaterally and palpable on DRE; the predominant site of origin (~70%) for prostatic adenocarcinoma.

Inability to retract the foreskin over the glans penis due to a narrow preputial orifice; associated with smegma accumulation, chronic inflammation, and increased penile SCC risk.

Prostate Imaging Reporting and Data System (score 1–5) standardising reporting of multiparametric MRI of the prostate; PI-RADS ≥4 has high specificity for clinically significant cancer

An isoenzyme expressed by seminoma cells and GCNIS; used as an immunohistochemical marker to identify these tumors in histological sections.

Serum PSA divided by prostate volume (measured on TRUS); >0.15 ng/mL/cc suggests carcinoma over BPH; adjusts for volume-driven PSA elevation in BPH

The standard surgical approach for testicular tumors — the spermatic cord is ligated high in the inguinal canal and the testis removed; scrotal incision is contraindicated as it disrupts lymphatic drainage to inguinal nodes.

Rectangular eosinophilic crystalline cytoplasmic inclusions seen in ~25–40% of Leydig cell tumors; their presence is pathognomonic of Leydig cell differentiation.

A pathognomonic histological structure in yolk sac tumor consisting of a central fibrovascular core lined by tumor cells projecting into a cystic space, mimicking a primitive glomerulus.

The most common testicular GCT; composed of uniform large cells with clear cytoplasm resembling primitive germ cells, with a fibrous stroma containing lymphocytes; AFP-negative and highly radiosensitive.

A whitish sebaceous secretion that accumulates under the foreskin in uncircumcised males; contains desquamated cells, bacteria, and secretions; associated with chronic penile inflammation and carcinogenesis.

A distinctive testicular GCT of elderly men (>50 years) that does NOT arise from GCNIS and lacks i(12p); has a negligible metastatic risk and is cured by orchiectomy alone.

Disease confined to the testis (and spermatic cord/scrotum for higher T-substages) without evidence of nodal or distant metastases; carries ~95–99% five-year survival with appropriate treatment.

Large multinucleated cells resembling placental syncytiotrophoblast that produce β-hCG; present as the dominant component in choriocarcinoma and as minor elements ('syncytiotrophoblastic giant cells') in some seminomas.

A GCT containing mature or immature tissues from two or three embryonic germ layers (ectoderm, mesoderm, endoderm); in adult males, testicular teratoma has malignant potential unlike the ovarian equivalent.

A spectrum of male reproductive disorders (cryptorchidism, hypospadias, impaired spermatogenesis, GCT) attributed to fetal gonadal dysgenesis, possibly linked to in-utero exposure to endocrine-disrupting chemicals.

The most common somatic gene fusion in prostate cancer (~50% of cases); places the ETS-family transcription factor ERG under control of the androgen-regulated TMPRSS2 promoter, creating an oncogenic driver responsive to androgens

The periurethral zone of the prostate (~5–10% of normal gland volume) where BPH arises; becomes the dominant component in severely enlarged BPH glands

The periurethral zone of the prostate, comprising ~5% of normal gland volume; the predominant site of BPH; surrounded by the surgical capsule (condensed BPH-adjacent tissue plane used for enucleation).

Ultrasound probe inserted rectally to image the prostate; used to measure prostate volume, guide systematic needle biopsies, and detect gross lesions (though not reliable for early cancer detection)

Gold-standard surgical treatment for BPH; electrosurgical resection of transition-zone tissue via cystoscopic approach; chips sent for histology may reveal incidental carcinoma (Stage T1a or T1b)

A GCT recapitulating yolk sac (extraembryonic endoderm) differentiation, characterised by Schiller-Duval bodies and AFP secretion; the most common testicular tumor in infants under 3 years.

A glycoprotein normally produced by placental syncytiotrophoblast; markedly elevated in choriocarcinoma and mildly elevated in seminomas containing STGCs; used for diagnosis, staging, and monitoring.