'Testicular cancers are malignancies that can arise from testicular germ cells, sex cord stromal cells, and more rarely other cells in the testes. The two main malignant tumours of the testis are seminoma and non-seminomatous germ cell tumours (NSGCTs).

Cryptorchidism and ectopic testis are the most important risk factors for the aetiology of testicular cancer, associated with a three-fold increase.

Other risk factors of testicular cancer include:

Infertility

Hypospadias

Genetic effects/family history

Previous testicular cancer on the contralateral testis (associated with 12-times increased risk)

Less common risk factors with a strong association for testicular cancer include gonadal dysgenesis, testicular atrophy, HIV infection.

Of primary tumour mass

Palpable lump (painful or painless)

Often hard

May be associated with secondary hydrocele, which may contain blood-stained fluid

Acute pain (10% of cases)

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Of metastases, e.g. in the lung (breathlessness, haemoptysis), bone pain, abdominal mass due to involved lymph nodes, cervical lymphadenopathy

Occasionally, gynecomastia may be a feature, owing to the production of paraneoplastic hormones.

In germ cell tumours, polyploidization, aneuploidization, and chromosomal abnormalities are important events that occur during pathogenesis.

A hallmark of germ cell tumours is an anomaly of the chromosome 12p, occurring in the form of iso-chromosomes or additional copies of 12p.

Specific gene mutations are also seen in germ cell tumours, including mutations of genes coding for KRAS, MDM2, and many single nucleotide polymorphisms.

Serum markers: β-HCG, AFP, LDH 

These markers are useful not only in the initial diagnosis but also in monitoring and post-treatment follow-up. 

Ultrasound

is the most important test in the diagnosis of testicular cancer due to its high sensitivity, non-invasive nature, and the lack of radiation exposure.

CT abdomen and pelvis

is used in staging and assessing the degree of metastasis. It can also be used in diagnosis when ultrasound is inconclusive.  CT chest is indicated when

• Difference strategies are employed depending on whether there is lymph node involvement (stage II) and metastasis to visceral organs (stage III).

• Orchidectomy of the affected side is curative for stage I disease. 

• Histopathological analysis of the sample is subsequently undertaken to determine the exact cancer type, which will guide management in stage II and III disease.

• Adjuvant chemotherapy is required for stage I seminoma post-orchidectomy to reduce the rate of relapse. 

• Chemotherapy for stage II and III germ cell tumours.

• Radiotherapy can be considered for metastasis of seminomas due to their radiosensitivity.

Testicular cancer accounts for 1% of cancers in men, but is the most common solid tumours in men aged 20 to 34 years. Western countries have the highest incidence of testicular cancer, in the UK incidence has been estimated at 6.3 per 100 000.

Around 50% of all testicular cancers are seminomas, with the median age of diagnosis at 37 years. Non-seminomas have a median age of diagnosis of 30 years. 

70% of patients are diagnosed with stage I disease, and 30% are diagnosed with metastatic disease.

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