Burned-out testis tumours may be present if there is metastatic retroperitoneal lymphadenopathy, but the primary testicular tumour is a relatively occult, scarred intratesticular focus. Approximately 50% of the "burned-out" tumours continue to harbour malignant cells.

Pathology

Retroperitoneal germ cell tumours are more often secondary (unlike mediastinal and CNS germ cell tumours), and for secondary retroperitoneal germ cell tumours, the testes are the most common origin. An occult burned out germ cell tumour may represent ~10% of apparently primary retroperitoneal germ cell tumours ³.

A germ cell tumour presumably "burns out" when it outstrips its blood supply and then regresses. Non-seminomatous germ cell tumours have the highest rate of regression.

Radiographic features

Ultrasound

• small echogenic intratesticular scar in a patient with metastatic-appearing retroperitoneal lymphadenopathy
• may be calcified

Treatment and prognosis

Orchidectomy is still performed because ~50% of "burned out" testicular tumours continue to harbour malignancy despite systemic chemotherapy ⁴. Radiotherapy is sometimes used.

History and etymology

The concept of the "burned out" testicular tumour was first described by Prim in 1927 ¹, but the term "Azzopardi tumour" arose in 1961 after Azzopardi described the phenomenon in patients who had died of metastatic choriocarcinoma and nonseminomatous germ cell tumours ⁵.

Differential diagnosis

• testicular microlithiasis
• old testicular traumatic injury