Pathology case study 1 ~ Education

A 25 y.o. male presented to his general practioner with a right testis mass. Clinical investigation showed normal serum markers and there was no other radiological evidence of disease.

Macroscopic appearance:

Testis with seminoma

Right testis with pale, circumscribed tumour

On sectioning the testis contained a pale, circumscribed tumour, 25 x 20 x 13mm which was confined to the testis.  There was no macroscopic necrosis.




Microscopic appearance:

High power seminoma

Sheets of tumour cells with associated small lymphocytes

Low power of seminoma

Low power view with tumour and adjacent normal parenchyma

The tumour was composed of solid sheets of cells with ovoid vesicular nuclei, prominent nucleoli and moderate amounts of clear cytoplasm. There where associated clusters of small lymphocytes. There was no lymphovascular invasion and the lesion was confined to the testis. There were no non-seminomatous germ cell elements. The surrounding parenchyma showed associated intra-tubular germ cell neoplasia.

Pathological diagnosis: Seminoma

Discussion: Seminoma is the most common germ cell tumour of the testis (up to 50%) and occurs at a mean age of 40y.o. The tumour cells are ‘un-differentiated’ germ cells and are seen in large sheets with thin intervening fibrous bands and often some associated clusters of lymphocytes.

From a clinical perspective, the most important histological features to recognise include the extent of tumour involvement including any extension beyond the testis and involvement of any surgical margin, the presence or absence of lymphovascular invasion and the presence or absence of other germ cell components.

Additional resources:

For patients – This site gives a nice overview of testicular cancer in general.

For medical specialty trainees  – gives a good pathology summary


This is a short video showing some of the histological features of seminoma.


This case is de-identified and intended for education purposes only.

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