46. Mixed germ cell tumor with seminoma and teratoma

Organ: Testis

Description:

There are two different cancers on this preparation. On the superior half there is an embryonal carcinoma, which is brownish and has a focus of greyish necrosis.

On the inferior half there is a seminoma, which is bright greyish, lobulated and almost homogenous. There is no necrosis in the seminoma.

Diagnosis: Mixed germ cell tumor with seminoma and embryonal carcinoma

Risk factors:

20-30 years old males

Theory:

Seminomas develop from germ cell neoplasia in situ (GCNIS), which again develops from a primitive germ cell.

Testicular germ cell tumors are mixed in approx. 60% of cases, meaning that multiple histological types are present, like in this case.

Isochromosome 12p, which means that the long arm (q) of the chromosome is replaced with another copy of the short arm (p), is found in virtually all germ cell tumors, including this one.

The title of the topic states that there is a teratoma in this prep, but there isn’t. It’s a mistake. Embryonal carcinoma is not a type of teratoma.

Some teachers say that the top tumour is the seminoma and the bottom one is the embryonal carcinoma.