Sonographic and magnetic resonance imaging appearance of a burned-out testicular germ cell neoplasm

Unusual imaging findings associated with abdominal pediatric germ cell tumors

Germ cell tumors of childhood are tumors arising from germline cells in gonadal or extragonadal locations. Extragonadal germ cell tumors are characteristically located in the midline, arising intracranially or in the mediastinum, retroperitoneum, or pelvis. These tumors are generally easily diagnosed due to typical sites of origin, characteristic imaging findings, and laboratory markers. However, germ cell tumors can be associated with unusual clinical syndromes or imaging features that can perplex the radiologist. This review will illustrate atypical imaging/clinical manifestations and complications of abdominal germ cell tumors in childhood. These features include unusual primary tumors such as multifocal primaries; local complications such as ovarian torsion or ruptured dermoid; atypical presentations of metastatic disease associated with burned-out primary tumor, growing teratoma syndrome, and gliomatosis peritonei; endocrine manifestations such as precocious puberty and hyperthyroidism; and antibody mediated paraneoplastic syndrome such as anti-N-methyl-D-aspartate-receptor antibody-mediated encephalitis. This review aims to illustrate unusual imaging features associated with the primary tumor, metastatic disease, or distant complications of abdominal germ cell tumors of childhood.

A massive retroperitoneal mature teratoma from a "burned-out" testicular teratoma and seminoma

Germ cell tumors are the most common nonhematologic malignancy of young men which often present with metastasis to the retroperitoneum, however a primary retroperitoneal mass should also be considered. The case presented herein reports a 42-year-old male presenting with a massive heterogenous retroperitoneal mass determined to be a mature cystic teratoma. Further investigation revealed a multifocal right testicular mass containing both a viable pure seminoma and a fibrous scar demonstrating germ cell neoplasia in situ thus representing the rare phenomenon of a "burned-out" mixed germ cell testicular tumor. When the radiologist is faced with a large retroperitoneal fat-containing mass, the differential includes a renal angiomyolipoma, liposarcoma, or germ cell tumor (whether primary or secondary). If pathology reveals a germ cell tumor, it is imperative to perform a thorough evaluation of the gonads, as it is much more common for a retroperitoneal germ cell tumor to be a metastasis from the gonads, rather than primary in origin.

Regressed testicular germ cell tumour in a post-pubertal male

Testicular germ cell regression is a rare, generally metastatic phenomenon which describes the spontaneous, complete, or partial regression of a testicular germ cell tumour. As a result, studies have focused on defining specific histopathological criteria to establish if the resected testis is the primary source of the germ cell tumour. There are few publications which describe its presentation in the absence of distant metastases with elevated tumour markers and suspicious findings on testicular ultrasound. We present the clinical presentation and radiological features of a non-metastatic regressed testicular germ cell tumour following scrotal trauma in a post pubertal male.

A scoping review on the "burned out" or "burnt out" testicular cancer: When a rare phenomenon deserves more attention

The "burned out" or "burnt out" testicular cancer (BTC) indicates the spontaneous and complete regression of a testicular germ cell tumor in the presence of distant metastases at the diagnosis. As this condition was never reviewed systematically, a scoping review was conducted to scrutinize the available literature on clinical and histological features of BTC patients. Medline was searched from inception to 19 April 2020. A virtual cohort of 68 BTC patients was generated. Our findings highlighted some inconsistencies: BTC was diagnosed in 5,9% of patients not showing distant metastases and in 2,9% of patients who did not undergo an orchiectomy. Besides, evidence of residual tumor was found in 22,7% of testis specimens, recognized as seminoma in 40% of cases. The emerged inconsistencies may derive from the lack of an unequivocal definition of BTC. Larger collaborative studies are needed to define the best diagnostic workup and treatment for BTC patients.

The Rare, the Odd, and the Atypical: A Pictorial Essay of Testicular and Paratesticular Diseases

ABSTRACT

Understanding a variety of scrotal diseases is essential to developing an accurate differential diagnosis and is critical in providing optimal patient care. Ultrasound is the imaging modality of choice when evaluating for scrotal pathology, with the major purpose of locating such pathology to either the testis, or epididymis, or other intrascrotal structures, as well as characterizing lesions as solid or cystic. It is generally assumed that most solid intratesticular masses are more likely malignant, whereas most extratesticular ones are benign, although some exceptions to that rule exist. This pictorial essay will focus on rare and less commonly encountered benign and malignant testicular and paratesticular pathologies, which may pose a diagnostic dilemma for interpreting radiologists and treating physicians. Knowledge of their imaging characteristics will help narrow the differential diagnosis and assist in proper patient management and care.

Spontaneous testicular tumor regression: case report and historical review

Spontaneous regression of a primary testicular germ-cell tumour (GCT), over time known as 'Burned out', 'Shrinking Seminoma', 'pT0', 'Burnout' or 'Spontaneous Regression', is an uncommon, generally metastatic phenomenon, which may present elevated tumour markers and a suspicious testicular ultrasound image. The histological study of the testicle demonstrated morphological changes of complete or partial tumour regression and found fibrous scarring and other characteristic changes of this phenomenon, which in some cases include vestiges of GCT. There are few publications on testicular GCT tumour regression and those that exist present limited data on the biology of the disease and its etiopathogenesis. This entity was recently recognised in the latest edition of the World Health Organization's (WHO) Classification of Tumours. We present our clinical, imaging, laboratory, cytohistological and management experience, as well as a historical review of the literature.

Burned-Out Testis Tumors in Asymptomatic Infertile Men: Multiparametric Sonography and MRI Findings

Multiparametric testicular ultrasound and magnetic resonance imaging (MRI) findings were analyzed in a series of 10 infertile asymptomatic men presenting with pathologically confirmed burned-out testicular tumors. Color/power Doppler ultrasound (CDUS), shear wave elastography (SWE), contrast-enhanced ultrasonography (CEUS), and MRI were performed on 10, 5, 6, and 7 patients, respectively. All lesions appeared as a hypoechoic and hypovascular nodular area at CDUS, SWE, CEUS CDUS, and CEUS (if performed). Shear wave elastography showed a stiffer nodular area compared with the surrounding/contralateral tissues (13 versus 2 kPa); MRI revealed a well-delineated nodular area in hypointense signal on T2, a high apparent diffusion coefficient value, and a lack of enhancement.

Paraneoplastic neurological syndrome due to burned-out testicular tumor showing hot cross-bun sign

BACKGROUND

Paraneoplastic neurological syndromes (PNS) are rare remote effect of cancer. The antibodies and tumors associated with PNS have been well described, but there are still many clinically suspected cases in which no tumor or antibody can be identified. This is the first report of PNS showing hot cross-bun sign and caused by exceptionally rare underlying malignancy, such as burned-out testicular tumor.

CASE PRESENTATION

A 42-year-old man presented subacute progression of hearing loss and cerebellar ataxia. Cerebrospinal fluid showed continuous inflammation and magnetic resonance imaging (MRI) revealed cerebellar atrophy and hot cross-bun sign. Resection of tumors improved both laboratory findings and neurological signs and their pathology was seminoma.

CONCLUSION

Seminoma can cause PNS showing 8th cranial nerve palsy, cerebellar, and brainstem atrophy with hot cross-bun sign on MRI study. Extensive screening for onconeural antibodies was negative and thereby suggested that unknown antibodies worked for both antitumor immunity and induction of PNS.

Brain Metastases as Presenting Feature in 'Burned Out' Testicular Germ Cell Tumor

Testicular germ cell tumors (TGCTs) are the most common malignancy in males aged 20 to 39, and the incidence is increasing. TGCTs have a tendency to grow rapidly with a high risk of metastatic spread. TGCTs generally present with a palpable testicular mass, yet may present less commonly with symptoms arising from metastatic disease.  A 24-year-old otherwise healthy male presented with progressive headaches. Initial imaging reported a single mass in the right frontal lobe. Complete surgical resection revealed suspicion for metastatic poorly differentiated carcinoma with an inconclusive immunohistochemical profile. Further staging scans revealed pulmonary and pelvic tumor deposits. Tumor markers with alpha-fetoprotein, beta-human chorionic gonadotropin, and lactate dehydrogenase were not elevated. Follow-up cranial magnetic resonance imaging revealed intracranial disease progression and he underwent whole brain radiation therapy. Additional outside pathology consultation for chromosomal analysis revealed features consistent with a TGCT. A scrotal ultrasound revealed a minimally atrophic right testicle. With evidence supporting the potential for response to chemotherapeutic treatment in TGCT, the patient was started on cisplatin and etoposide. Bleomycin was planned for the second cycle of chemotherapy if his pulmonary function improved.  A salient feature of all invasive TGCTs is a gain in material in the short arm of chromosome 12, and is diagnostic if present. Although the initial pathology revealed a non-diagnostic metastatic tumor, further testing revealed amplification of chromosome 12p. The examination of poorly differentiated carcinomas of an unknown primary site using light microscopy and immunohistochemical profiling alone may be inadequate, and should undergo molecular chromosomal analysis. This case is presented for its unconventional presentation and rarity of occurrence. It brings forward the discussion of both the commonality of TGCT in young male adults, as well as the anomaly of a 'burned out' phenomenon. With unreliable tumor markers, nonspecific symptoms, and pathological findings, 'burned out' TGCTs may account for a challenging diagnosis in a variety of cases, especially with the presenting symptom arising from a less common metastatic site. This case adds to the increasing literature on a rare entity of the 'burned out' TGCT, and upon literature review, presents itself as the first reported case presenting with brain metastasis.

Value of dynamic, contrast-enhanced MRI & intraoperative ultrasound for management of a nonpalpable, incidental, testicular Leydig-cell tumor

We report a case of a small, intratesticular, incidentally identified, nonpalpable Leydig-cell tumor in which preoperative, dynamic, contrast-enhanced MRI was essential in characterizing the lesion as a neoplasm. Sonographic evaluation failed to demonstrate internal color Doppler flow, resulting in a differential diagnosis that included debris-filled cyst. At surgical resection, intraoperative ultrasound was essential to locate the mass and confirm complete removal. This case highlights the value of dynamic, contrast-enhanced MRI and intraoperative ultrasound for the management of incidental intratesticular lesions with indeterminate sonographic and Doppler characterization. Radiologists and urologists should be familiar with this approach to the incidental, sonographically indeterminate, nonpalpable intratesticular lesion identified on scrotal ultrasound.