Burned-out Testicular Tumour

A burned out testicular tumour is a germ cell tumour in which the primary lesion has regressed, leaving a scar, while metastases continue to grow. The testis may feel normal or slightly small.

It is found in a small share of men with metastatic germ cell tumours, in the order of 1 to 5%. It presents most often with a retroperitoneal mass.

Pathophysiology. Regression is thought to follow ischaemia of the primary tumour or an immune response, which leaves a fibrous scar with calcification, haemosiderin and lymphocytes.

Germ cell neoplasia in situ is found in about 40 to 60% of burned out lesions, and viable tumour remains in some.

Metastases may be seminoma like or nonseminomatous, and are staged and risk grouped by their histology and markers.

Extragonadal germ cell tumour is the main alternative explanation. A testicular scar supports a gonadal origin.

Back or abdominal pain from retroperitoneal nodes, a palpable abdominal mass, cough, dyspnoea, supraclavicular nodes, weight loss or gynaecomastia. Testicular examination is usually normal, or the testis is small and firm with a nodule. A history of testicular pain or injury may have been overlooked.

• Scrotal ultrasound of both testes: hyperechoic foci with shadowing (microliths or calcified scar), a hypoechoic stellate or wedge shaped scar, and microlithiasis. Normal ultrasound does not exclude the diagnosis.
• AFP, beta-hCG and lactate dehydrogenase.
• CT of chest, abdomen and pelvis. MRI of the brain for raised hCG or neurological symptoms.
• Biopsy of a metastasis (image directed) when markers are normal or the diagnosis is uncertain, with immunostains (OCT3/4, CD30, AFP, glypican-3, SALL4, beta-hCG), and exclusion of lymphoma and carcinoma. A raised AFP or hCG with a typical mass allows treatment without biopsy under germ cell tumour specialist direction.
• Pre-treatment: semen analysis, testosterone, creatinine clearance, audiometry and lung function.

Differential diagnosis.

• Extragonadal germ cell tumour (retroperitoneal or mediastinal)
• Lymphoma
• Metastatic carcinoma from another site
• Sarcoidosis or tuberculous nodes
• Testicular scar from infarction, trauma or infection
• Primary testicular tumour with small size

• Offer sperm banking before treatment.
• Chemotherapy by histology and prognostic group. Nonseminomatous or raised AFP: BEP for 3 cycles (good risk) or 4 cycles (intermediate and poor risk). Seminoma type: BEP for 3 cycles (good risk) or 4 cycles (intermediate risk), or EP for 4 cycles.
  • BEP is repeated every 21 days: bleomycin 30 units intravenously on days 1, 8 and 15, etoposide 100 mg/m2 on days 1 to 5, and cisplatin 20 mg/m2 on days 1 to 5, with hydration (1 to 2 L of saline before and after, plus magnesium and potassium).
  • Antiemetics for high emetic risk: ondansetron 8 mg, dexamethasone 12 mg and aprepitant 125 mg on day 1, then aprepitant 80 mg on days 2 and 3 with dexamethasone 8 mg on days 2 to 4.
  • Cisplatin needs creatinine clearance over 60 mL/min. Stop bleomycin for lung toxicity. Neutropenic fever needs intravenous antibiotics within 60 minutes.
• Orchidectomy of the affected testis (inguinal approach) after or before chemotherapy once stable, since viable tumour and germ cell neoplasia in situ can remain, and the testis is a site that chemotherapy may not clear. Testis sparing surgery with frozen section is an option in selected men.
• Residual masses over 1 cm after chemotherapy with normal markers: surgical resection (nonseminomatous disease), or PET-CT at least 6 weeks after chemotherapy for seminoma type disease.
• Relapse: salvage chemotherapy at a specialist centre.
• Long term care includes fertility and testosterone follow up, and cardiovascular risk review.

Monitoring. Markers and clinical review every 1 to 3 months in year 1, then every 3 to 6 months to year 5, with imaging at intervals set by the oncology team. Ultrasound of the contralateral testis yearly.

Referral and escalation. Refer to urology and to a specialist oncology centre. Urgent referral for markedly raised markers, symptomatic metastases or neutropenic fever.