Page 508 - Concise Pathology for Exam Preparation ( PDFDrive )

17 Male Genital Tract 493

(ii) Anaplastic seminoma (5–10%): Shows greater cellularity, more nuclear irregu-
larity, a larger number of tumour giant cells and three or more mitoses per high
power field (anaplastic seminoma is not treated differently from a typical semi-
noma because it does not have a worst stage-by-stage prognosis as compared to
the same)
(iii) Spermatocytic seminoma (4–6%): Classified separately due to differences in
clinicopathological profile when compared with a classical seminoma. It has
the following features:
Clinical presentation:
• Presents as a large testicular swelling
• Peak age: More than 65 years
• Slow-growing tumour that rarely metastasizes; has excellent prognosis
Gross morphology: Larger than typical seminoma; cut surface is pale grey, soft
and friable
Microscopy:
• Composed of three distinct cell populations:
- Medium-sized cells (round nucleus and eosinophilic cytoplasm)
- Smaller cells (resemble secondary spermatocyte; have scanty eosinophilic
cytoplasm)
- Scattered giant cells (uninucleate or multinucleate)
• Lacks lymphocytes, granulomas and syncytiotrophoblasts
(b) Nonseminomatous germ cell tumours (NSGCTs)
(i) Yolk sac tumour
• Also called endodermal sinus tumour, orchioblastoma and infantile
embryonal carcinoma
• Most common testicular tumour of infants and children up to three years of age
• The pure form is uncommon in adults, in who it frequently occurs in combination
with embryonal carcinoma.
• AFP level is elevated in all cases of yolk sac tumour.
Gross morphology: Unencapsulated; cut surface is yellow-white, mucoid with
area of necrosis, haemorrhage and microcyst formation
Microscopy:
• Tumour cells are flattened to cuboidal with clear to vacuolated cytoplasm,
arranged in a variety of patterns varying from loose, lace like or reticular to
tubular, tubulopapillary and solid.
• Cells may form distinct perivascular structures, ie, a central blood vessel
or mesodermal core surrounded by germ cells arranged in visceral and
parietal layers like glomeruli (resemble yolk sac or endodermal sinus of rat
placenta called Schiller–Duval bodies).
• Intracellular and extracellular PAS-positive hyaline globules may be present.
• Tumour cells may also contain AFP and a 1 -antitrypsin.
(ii) Choriocarcinoma
• Highly malignant form of testicular cancer
• May arise in placental tissue, ovaries, mediastinum and abdomen (from
sequestered totipotential cells)
• Pure form of choriocarcinoma is rare; mostly mixed tumours
• The serum and urinary levels of HCG are greatly elevated in all cases.
Gross morphology:
• Generally, does not cause testicular enlargement, detected only as a small
palpable nodule.
• Areas of haemorrhage and necrosis are extremely common.
• Tumour may undergo extensive ischaemic necrosis to be eventually replaced
by a fibrous scar leaving behind extensive metastasis.
Microscopy: Two types of cells are seen without formation of placental type
villi, namely:
- Syncytiotrophoblasts: Large, multinucleated cells with irregular or lobular
hyperchromatic nuclei and abundant eosinophilic cytoplasm; HCG is local-
ized to their cytoplasm.

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