GENITOURINARY PATHOLOGY

CHAPTER 2 GENITOURINARY PATHOLOGY



Bladder and prostate pathology

Introduction

Urothelial papilloma

Testicular and paratesticular pathology
Testicular germ cell tumors
Seminoma

Embryonal carcinoma

Yolk sac tumor

Choriocarcinoma

Teratoma

Mixed germ cell tumor

Testicular sex-cord stromal tumors
Leydig cell tumors

Sertoli cell tumor

Juvenile granulosa cell tumor

Gonadoblastoma

Secondary testicular involvement

Vanished testis / testicular regression syndrome (TRS)

Cryptorchidism

Testicular and testicular appendage torsion

Paratesticular / adnexal tumours

Nontumorous paratesticular masses

Cystic dysplasia of the rete testis (CDRT)

Intersex / disorders of sexual differentiation (DSD)


BLADDER AND PROSTATE PATHOLOGY



INTRODUCTION



• Prostate / seminal vesicle pathology is rare in childhood other than involvement by rhabdomyosarcoma

• Bladder specimens predominantly comprise:
image biopsies for assessment of tumor
– usually rhabdomyosarcoma (specific issues detailed in the relevant tumor section)

image specimens with non-specific reactive changes following surgery for congenital bladder anomalies such as bladder extrophy repair

• Other bladder lesions biopsied are rare and include the following



Bladder paraganglioma



• Rare, but reported in children

• Paroxysmal episodes of hypertension, sweating, headache, hematuria

• Histopathological features of paraganglioma at other sites (see tumor section)


Bladder neurofibroma



• Children with NF

• See neurofibroma section


UROTHELIAL PAPILLOMA



Epidemiology



• Mainly adults but reported in childhood


Clinical features



• Hematuria


Histopathological features (Figs 2.1, 2.2)



• Papillary structures with no urothelial atypia

• Stromal edema

• Low proliferation rate and rare basal mitoses only

image

Fig. 2.1


image

Figs 2.1–2.2 Photomicrographs of a bladder transitional cell papilloma, demonstrating papillary architecture and no significance cytological atypia.



Immunohistochemical staining



• No p53 abnormalities
image cf papillary carcinomas


Differential diagnoses and pitfalls



• Inverted papilloma
image bland urothelium in nests / cords within lamina propria

• If thickened or atypical urothelium then papillary urothelial neoplasm of low malignant potential (PUNLMP)
image very rare in childhood


TESTICULAR AND PARATESTICULAR PATHOLOGY



TESTICULAR GERM CELL TUMORS




Epidemiology



• Most germ cell tumors are seminoma in young adulthood

• In younger childhood, classical seminoma rare

• Childhood peak in infancy
image teratomas

image yolk sac tumors


Genetics



• Familial cases reported but usually tumors develop in adulthood

• Intersex with Y chromosome at increased risk (up to 50%)
image tumors develop in adulthood

• Adult cases i12p associated, in contrast to childhood cases


Clinical features



• Painless testicular mass


Histopathological features (Figs 2.3–2.18)




SEMINOMA



• Mainly affects adolescents when occurs in childhood

• Sheets of uniform round to ovoid cells

• Minimal pleomorphism in most cases

• Fine trabeculae

• Associated lymphoid infiltrate

• PLAP and CD117 + in almost all

image

Fig 2.3 Photograph of a testis with a malignant yolk sac tumor. The capsule is stretched and the cut surface (inset) is solid with areas of hemorrhage.


image

Fig. 2.4


image

Fig. 2.5


image

Fig. 2.6


image

Fig. 2.7


image

Figs 2.4–2.8 Photomicrographs of testicular malignant yolk sac tumors, demonstrating the range of morphological appearances including microcystic, reticular, solid and papillary patterns.


image

Fig. 2.9


image

Figs 2.9–2.10 Photomicrographs of testicular malignant yolk sac tumors, demonstrating the tumor cells highlighted by cytokeratin (Fig 2.9) and alphafetoprotein (Fig 2.10) immunostaining.


image

Fig. 2.11


image

Fig. 2.12


image

Fig. 2.13


image

Fig. 2.14


image

Fig. 2.15


image

Figs 2.11–2.16 Photomicrographs of testicular teratomas, demonstrating a wide range of mature tissue elements (mature) in addition to immature neuroepithelial tubular structures (immature).


image

Fig. 2.17


image

Figs 2.17–2.18 Photomicrographs of testicular teratomas in which there are additional focal areas of malignant yolk sac tumor. The identification of such malignant areas is important and highlights the need for adequate specimen sampling.



EMBRYONAL CARCINOMA



• Rare

• Sheets, papillae and cysts with poorly differentiated cells

• Polygonal with vesicular nuclei
image prominent nucleoli

image overlapping nuclei

• CD30+

• CK+

• Focal PLAP+


YOLK SAC TUMOR



• Commonest malignant GCT in infancy

• 90% associated with elevated serum aFP levels

• Ovoid vacuolated cells with scattered hyaline globules

• Mitotically active

• Numerous patterns, most cases show features of many admixed
image microcystic / reticular

image macrocytic

image solid

image alveolar

image endodermal sinus (Schiller–Duval bodies)

image papillary

image myxomatous

image polyvesicular / vitelline

image hepatoid

image enteric

• Cytokeratin+

• aFP focally+


CHORIOCARCINOMA



• Very rare in childhood even as component of mixed malignant GCT

• Cytokeratin+, inhibin+, hCG+


TERATOMA



• Infancy

• Composed of tissues recapitulating all three germ layers

• Well demarcated

• Wide range of tissue differentiation

• Sample carefully for malignant areas including focal PNET

• Benign behavior in infancy
image cf adults

• Note: pure testicular ‘epidermoid cyst’ may occur which has keratinizing squamous lining but no other elements
image sample extensively to exclude other teratoma elements


MIXED GERM CELL TUMOR



• Multiple combinations of above components


Differential diagnoses and pitfalls



• Most pediatric testicular GCTs are not associated with ITGCN (intratubular germ cell neoplasia)
image cf most adult GCTs

• Normal immature fetal germ cells express PLAP and CD117
image expression reduces during early childhood

image do not overdiagnose ITGCN in childhood testes on the basis of immunostaining only

• Infantile / congenital testicular tumors are most likely to be juvenile granulosa cell tumor rather than GCT


TESTICULAR SEX-CORD STROMAL TUMORS



LEYDIG CELL TUMORS



Epidemiology



• <5% pediatric testicular tumors

• 3–9 years in childhood


Clinical features



• Painless unilateral testicular enlargement

• Endocrine features may be present
image gynecomastia

image precocious puberty


Macroscopic features



• Well circumscribed yellow brown nodule


Histopathological features



• Diffuse sheets of large polygonal cells
image eosinophilic cytoplasm

image Reinke crystals <40%

Related posts:

  1. BONE PATHOLOGY
  2. HEAD AND NECK PATHOLOGY
  3. RENAL PATHOLOGY
  4. TUMORS AND TUMOR-LIKE LESIONS

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Jun 18, 2016 | Posted by in PEDIATRICS | Comments Off on GENITOURINARY PATHOLOGY

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