TUMORS of the TESTIS

incidence

risk factors

  • age peak: 25-35 ys
  • geographical distribution: west

classification (2016 WHO classification)

2-10x100.000, increasing

  • cryptorchydism
  • testicular dysgenesia
  • Kleinfelter syndrome
  • race (caucasians)
  • hereditary predisposition

germ cell (95%):
all malignant

seminomatous

non-germ cell (5%):
more frequently benign

MIXED GERM CELL TUMORS

  • 70% of non-seminomatous
  • with or without seminoma
  • any combination

distant metastases: 10% morphology not similar to primary

a minimum of 10 blocks for larger homogeneous tumors and complete blocking of smaller ones if entire tumor can be submitted in 10 blocks or less

precursor lesion: germ cell neoplasia in situ

  • found in cryptorchidism, infertility
  • risk of controlateral germ cell tumor in 25-50x
  • morphology: large clear/vacuolated cells (PAS+), with large irregular nuclei

no 12p gain

pathological relevance

  • to be differentiated from vascular invasion / intratubular spread
  • helps distinguish germ cell tumors vs sex chord tumors
  • helps to distinguish seminoma from spermatocytic tumor
  • may be found in biopsies for infertility
  • may be found in cryptorchidism

two pathways

default

SE

reprogramming

EC

it can also undergo the reprogramming path

SEMINOMA

  • the most frequent
  • 4th decade, pure or mixed
  • 94% at 4 ys
  • 12p isochromosome

histology

  • classic 85%
  • anaplastic 10%
  • with SCT

pathology

macro:

  • white-to-gray
  • lobulated
  • homogeneous
  • without hemorrhage or necrosis
  • with no involvement of the tunica albuginea

micro:

  • round-to-polygonal cells
  • medium size
  • aboundant clear cytoplasm (glycogen, PAS+)
  • hyperchromic nuclei, large nucleoli
  • dyscohesive pattern of growth
  • intratumoral lymphoid infiltrate

exception

  • seminoma with SCT cells beta-hCG+ variant
  • mixed

SPERMATOCYTIC TUMOR

  • 5% seminomatous
  • for the remaining %, specific tumor entity
  • cells generally smaller than in seminoma
  • more heterogeneous
  • similar to type II spermatocytes
  • not associated to GCNIS, no ovarian counterpart, no 12p anomalies, excellent prognosis, age >50

non-seminomatous

EMBRYONAL CARCINOMA

pathology

macro:

  • small testicular nodules with necrosis and hemorrhage
  • infiltration of the tunica albuginea

micro:

  • tubular
  • alveolar
  • papillary
  • chordonal growth of epithelioid cells with high grade atypia
  • CD30+ and CEA+

YOLK SAC TUMOR

types:

prebuperal:

  • children <3 y,
  • pure,
  • good prognosis

post-puberal:

  • adults <30 y,
  • mixed,
  • highly malignant

pathology:

micro:

  • irregular sheets of cuboidal cells
  • papillae
  • tubules
  • centrifugal pattern

macro:

similar to embryonal carcinoma

PAS+ and AFP+
globules in the cytoplasm

CHORIOCARCINOMA

  • pure form <1%
  • mixed in 8% of germ cell tumors
  • 25-30 y
  • highly malignant

pathology

macro:

  • small lesions
  • marked hemorrhage
  • necrosis

micro:

  • large cells with cyto-syncytio-trophoblastic differentiation
  • pale-to-eosinophilic cytoplasm

TERATOMA

  • heterogeneous tumor
  • pure in children (pre-pubertal type, benign, desmoid/epidermoid cysts)
  • complex forms in adults (post-pubertal type), including mixed with embryonal carcinoma

pathology

macro:

heterogeneous

micro:

mature

mixed histologies: nervous tissue, muscle, thyroid, bronchi, cartilage, intestine, epidermis, connective tissue

immature

same as mature, but embryonal-like with some degree of cytological atypia

malignant transformation

  • rhabdomyosarcoma, PNET, wilms, squamous cell carcinoma, adenocarcinoma
  • expansile and infiltrative growth of epithelial or mesenchymal component measuring >5mm
  • prognostic impact: not completely known in the primary, in metastatic lesions poor response to chemotherapy

serum markers

  • alpha fetoprotein
  • beta hCG
  • PLAP
  • CEA
  • LDH

role:

  • nature of the primary lesion
  • staging
  • response to therapy
  • follow up
  • germ cell vs non-germ cell nature
  • histological typing
  • prognosis

IHC germ cell tumor algorithm

OCT4+

OCT4-

+CD117
-CD30

-CD117
+CD30

embryonal carcinoma

seminoma

+glypican 3
+/-AFP
-hCG
+/-PLAP

yolk sac tumor

-glypican 3
-AFP
-hCG
-PLAP

spermatocytic seminoma

+/-glypican 3
-AFP
+hCG
+/-PLAP

choriocarcinoma

LEYDIG CELL TUMOR

  • yellowish
  • <5 cm
  • Leydig cells with Reinke crystals
  • lipofuscins
  • mostly benign
  • rare

in children: precocious puberty

in adults: gynecomastia and feminization

IHC markers: alpha inhibitin, SF1, melan A

SERTOLI CELL TUMOR

  • aka androblastoma
  • yellow-to-white
  • very rare
  • chords or trabeculae or tubules
  • prominent stroma in some cases
  • broad spectrum of DD: SF1+, CD99+, melan A+, chromogranin A+, cytokeratins
  • asymptomatic / gynecomastia
  • malignant in 5% of cases

other tumors:

  • theca-/granulosa cell tumors
  • mixed sex chord/germ cell tumors
  • unclassified
  • lymphoma: 2% of testicular tumors, 40-60% primary,
    age 60-80 y, usually diffuse large B cell type
  • carcinoid
  • mesothelial tumors: paratesticular; adenomatoid
    tumor and mesothelioma
  • soft tissue tumors: lipoma, leyomyoma,
    rhabdomyosarcoma
  • metastases

staging 2017

  • rete testis invasion
  • size of tumor
  • epididymal invasion
  • tunica vaginalis invasion
  • vascular invasion
  • soft tissue invasion
  • cord invasion

NEVER CONSIDER INGUINAL LYMPH NODES INVOLVEMENT IN THE CASE OF TESTICULAR METASTASES!!!!!

non-neoplastic pathology

developmental anomalies

pseudohermaphroditism

primary hypogonadism

  • isolated LH deficit
  • Klinefelter syndrome (testicular atrophy, azoospermia, gynecomastia)

cryptorchidism

  • 5% males at birth
  • trans-abdominal and inguino-scrotal phases
  • unknown causes (hormones, trisomy 13?)
  • 25-30% bilateral
  • isolated or associated with other anomalies

decreased volume and increase consistency of the testis

micro: maturation arrest of germ cells (atypia), decrease in Sertoli cell number, tubular hyalinization and basal membrane thickening

  • 2-10% pure, usually mixed
  • age 20-30 y
  • EARLY DEVELOPMENT OF DISTANT METASTASES (lung)
  • Leydig cell agenesis
  • deficit in testosterone synthesis
  • insensitivity to androgens --> Morris syndrome, undifferentiated tubules, Leydig cell hyperplasia

risk of malignant transformation: 3-5 (7-11) x

atrophy

  • focal
  • diffuse

causes:

  • ischemia
  • post-inflammatory
  • cryptorchidism
  • hypopituitarism
  • iatrogenic
  • peritumoral

torsion

  • twisting of the spermatic chord, leading to blockade of venous blood flow
  • swelling, edema, hemorrhage, necrosis

newborns or adults: increased mobility of the testis for bilateral laxity of the gubernaculum testis

inflammatory disorders

acute specific: granulocytes and macrophafes / interstitial and then intratubular --> abscess

specific forms:

gonococcus from urethritis

mumps --> rare complication in children, 20% in adults, 70% monolateral, with lymphocytes and plasma cells

testicular TBC

  • post-primary
  • uni-/bilateral
  • granulomatous, productive caseous process
  • fistulae
  • primary of the epididymis, late testicular lesions
  • hematogenous spread or canalicular from the urinary tract

syphilis

epididymitis:

  • congenital
  • acquired

obliterative endoarteritis with perivascular infiltrate of lymphocytes and plasma cells

granulomatous lesions: scar --> gumma

autoimmune diseases

  • granulomatous orchitis
  • middle-aged men
  • sudden unilateral enlargement of the testis
  • fever and pain

intra- and inter-tubular granulomatous inflammation with localized fibrosis and atrophy

no epididymitis (important for TBC DD)

male infertility

pre-testicular causes

  • hypopituitarism
  • estrogen and androgen excess
  • glucocorticoid excess
  • hypothyroidism
  • diabetes

post-testicular causes

  • congenital or acquired stenosis of the deferens ductus
  • impaired sperm cell motility

testicular causes

  • maturation arrest
  • hypospermatogenesis
  • "sertoli cell only" syndrome
  • Klinefelter syndrome
  • cryptorchidism
  • radiation exposure
  • post-inflammatory diffuse sclerosis

testicular biopsy

adequate material, clinical information and hormonal tests

  • normal parenchyma
  • hypospermatogenesis
  • maturation arrest
  • germ cell loss (Sertoli cell only vs. end-stage testis)
  • fibrosis / atrophy
  • GCNIS