Mixed germ cell tumour

Mixed germ cell tumour
Diagnosis in short
Mixed germ cell tumour. H&E stain.
LM	depends on the components
LM DDx	other germ cell tumours
IHC	variable
Site	ovary, testis, mediastinum, other
Signs	mass lesion
Prevalence	most common germ cell tumour
Blood work	+/-AFP elevated, +/-beta-hCG elevated, +/-LDH elevated
Prognosis	worse than seminoma/dysgerminoma
Clin. DDx	gonads: germ cell tumours, other tumours

Mixed germ cell tumour, abbreviated MGCT, is a lesion composed of different germ cell tumours. Most germ cell tumours are mixed.

General

• 60% of GCTs are mixed. †

Common combinations:

1. Teratoma + embryonal carcinoma + endodermal sinus tumour (yolk sac tumour) (TEE).
2. Seminoma + embryonal (SE).
3. Teratoma + embryonal +(TE).

Memory device: TEE + all combinations have embryonal carcinoma.

Note:

• † Numbers vary between sources. One series suggests it is almost 70%.
• There has been in increase in MGCTs over the past 20 years that is probably due to changes how in how GCTs are classified.

Microscopic

Features:

• Depends on components.

Notes:

• If one cannot identify the component... it is probably yolk sac as this has so many different patterns.

Images

• 

  Mixed GCT - intermed mag. (WC/Nephron)

• 

  Mixed GCT - high mag. (WC/Nephron)

www:

• Mixed germ cell tumour - several images (upmc.edu).
• Mixed germ cell tumour - several cases (upmc.edu).

IHC

• Beta-hCG +ve - if syncytiotrophoblasts are present.
• AFP +ve - a yolk sac tumour component is present.
• GFAP +ve - if neuroepithelium is present.

A panel:

• PLAP.
• CD30 - embryonal carcinoma.
• CD117 - seminoma.
• Pankeratin - embryonal carcinoma.
• CEA-M.
• EMA.
• Vimentin.
• AFP - yolk sac tumour.
• A1A - yolk sac tumour.

See also

• Germ cell tumours.
• Testis.
• Ovarian tumours.