The chest radiograph shows ‘cannon ball’ lesions – multiple bilateral spherical lesions of varying size that are predominantly preipherally located.
An endotracheal tube and nasogastric tube are present and appropriately positioned.

The likely diagnosis is metastatic cancer involving the lungs.

But where is the primary?

• Tumors with rich systemic venous drainage are most likely to metastasize to the lungs.
  e.g. choriocarcinomas, melanomas, testicular germ cell tumours, renal cancers, osteosarcomas and thyroid carcinomas.

• However, lung metastases most commonly arise from more common tumours.
  e.g. breast, colorectal, prostate, bronchial, head/neck, and renal cancers.

The following should be carefully examined in a patient with suspected malignancy:

• all lymph nodes draining the region of a suspected lesion
• all remaining accessible lymph node groups
• the abdomen, specifically looking for hepato/splenomegaly and ascites
• the testes
• rectum
• lungs
• breasts and pelvis in females
• skin, nails and retina for melanoma
• focal neurological deficits

A large right-sided firm scrotal mass was palpable on physical examination and an urgent urology referral was made.

Ultrasonography confirmed the mass to be intratesticular with normal surrounding tissues. The mass was solid, ~6 cm in diameter, and had some cystic changes and slightly increased vascularity.

Sagittal view of normal testis

Sagittal view of abnormal testis

A CT head and chest were also performed, followed by an MRI of the brain, abdomen and pelvis once the patient was extubated. Sample images from the CT chest and MRI brain demonstrating the presence of lung and cerebral metastases are shown below:

CT Chest

MRI brain

Metastatic testicular cancer.

• Testicular cancer is the most commonly diagnosed cancer in men between the ages of 15 years and 35 years.
• About 1 in 20 testicular cancers have already metastasised at the time of diagnosis, and a similar number involve both testes.
• Risk factors include:
  cryptorchidism, family history (especially first degree relatives), genetic disorders (e.g. Klinefelters and Down syndrome), infertility, testicular atrophy, HIV, white race and smoking.

There are numerous different types of testicular cancer. 95% are germ cell tumours (GCTs) and 1 in 3 of these are mixed cell types. Of the pure GCTs the main distinction is between:

• seminomas (~50%)
• non-seminoma germ cell tumours (NSGCT):
  • including embryonal carcinomas, yolk sac tumours, teratomas, and choriocarcinomas
  • mixed cell type tumours behave like NSGCTs.
  • These are more aggressive than seminomas.

This patient was diagnosed with a NSGCT as both beta-human chorionic gonadotrophin (bHCG) (>350,000 mIU/mL) and alpha-fetoprotein (AFP) were grossly elevated.

• AFP is not elevated in pure seminomas.

The patient underwent a unilateral orchidectomy and BEP chemotherapy (bleomycin, etoposide and cisplatin) was commenced. He may also need radiotherapy and/or surgery to treat his cerebral metastases.