Spontaneous regression or the ‘burned-out’ phenomenon of testicular germ cell tumors is well-recognized but a rare clinical entity of which few reports exist. Tumors with the ‘burned-out’ phenomenon are found in metastatic sites, not in the testis. We report a 33-year-old patient who presented with liver choriocarcinoma and a retroperitoneal mass with the ‘burned-out’ phenomenon in the testis.
The ‘burned-out’ phenomenon in germ cell tumors is defined as the presence of an extragonadal germ cell tumor with no evidence of a testicular neoplasm. This condition is different and less common than primary extragonadal germ cell tumors, which represent 2%–5% of adult germ cell malignancies. The origin of extragonadal germ cell tumors remains a matter of debate, and whether such tumors represent metastases of a primary testicular tumor or develop primarily at extragonadal sites is uncertain. Subsequently, Azzopardi et al. [
We describe spontaneous regression of a primary testicular tumor with metastatic liver and retroperitoneal germ cell tumors, known as the ‘burned-out’ phenomenon.
A 33-year-old man presented with left upper quadrant pain and dyspepsia. The patient had a orchiopexy history due to bilateral cryptorchidism. An abdominal computed tomography (CT) scan showed a retroperitoneal mass of 10.7×9.5×16 cm abutting the aorta (
A few reports from the early 20th century suggested that testicular germ cell tumors may undergo spontaneous regression. Friedman [
Several immunological and ischemic mechanisms have been suggested to explain this spontaneous regression, but immunological mechanisms appear to be the most likely [
Patients with extragonadal germ cell tumors and spontaneous regression in the testis usually show various clinical symptoms. In this case, our patient complained of left upper quadrant pain and dyspepsia. Although we suspected a testis-originating extragonadal germ cell tumor because of the elevated β-hCG, it was insufficient for the diagnosis. Scrotal ultrasonography may be helpful in such a situation. Comiter et al. [
Radical orchiectomy with spontaneously regressing testis is controversial. Although current chemotherapy is largely effective against all type of metastatic testicular germ cell tumors, it is often not effective against primary testicular tumors because of the ‘blood–testis barrier’ [
Cisplatinum-based chemotherapy after radical orchiectomy of a primary testicular tumor is the basis of the treatment regimen [
The ‘burned-out’ phenomenon, known as spontaneous regression of a primary testicular tumor, is difficult to recognize and has been incompletely characterized by physicians. Extragonadal germ cell tumors in the retroperitoneum, liver, and other organs should be considered for the ‘burned-out’ phenomenon. Additional studies are needed to identify the exact mechanism and further delineate the nature of the ‘burned-out’ phenomenon.
(A, B) Computed tomography scan showing a huge retroperitoneal mass (white arrows) and a low-density liver lesion (black arrow). Left renal parenchymal enhancement was reduced by compressing the retroperitoneal mass.
(A) Gross findings of a white-to-tan colored and well-delineated nodular mass of the left testis measuring 1.5×1.5 cm. (B) Microscopic findings of the left testis showed testicular atrophy, as demonstrated by shrunken seminiferous tubules with decreased spermatogenesis and aggregation of Leydig cells (H&E, ×40).
Microscopic findings of the liver needle biopsy showed both neoplastic cytotrophoblasts and syncytiotrophoblasts. These findings were consistent with metastatic choriocarcinoma (H&E, ×200).