Clinical image. MRI of scrotal hemangioma

Review of paratesticular pathology: findings on ultrasound and MRI

The paratesticular scrotal contents consist of the spermatic cord, epididymis, and fascia, which originate from the embryologic descent of the testis through the abdominal wall. Historically, the primary diagnostic modality has been high-resolution ultrasound. Magnetic resonance imaging (MRI) is an alternative imaging option. Both contrast MRI and diffusion weighted imaging can assist in differentiating between benign and malignant lesions. Unlike the testis which most disease processes are malignant, a wide spectrum of benign disease processes affects the paratesticular region either in isolation or as part of a contiguous disease process from adjacent organs. The familiarity with the epidemiology, pathogenesis, and imaging features can aid the radiologic diagnoses and guide appropriate clinical management. In this article, we review the ultrasound and MR characteristics of various paratesticular pathologies.

Testicular and paratesticular tumours in the prepubertal population

Prepubertal testicular and paratesticular tumours are a rare group of tumours, distinct from postpubertal paediatric and adult tumours of this region. Tumours within this group are testicular germ-cell tumours (such as benign teratoma, epidermoid cyst and malignant yolk-sac tumours) and stromal tumours (such as juvenile granulosa-cell, Leydig-cell, and Sertoli-cell tumours). Paratesticular tumours can be benign (lipoma, leiomyoma, haemangioma) or malignant (rhabdomyosarcoma, melanotic neuroectodermal tumour of infancy). Because of their rarity, centralised pathology and treatment, and national collaborative clinical trials have been important in establishing the optimum management of malignant tumours in this group. We provide an up-to-date and comprehensive review of the clinical presentation, imaging, pathology, and clinical management of prepubertal paratesticular and testicular tumours.

Multimodality imaging of paratesticular neoplasms and their rare mimics

Extratesticular neoplasms are rare but clinically significant lesions that affect patients of all ages. These neoplasms are generally asymptomatic but may have potentially life-threatening sequelae. Lipoma is the most common primary benign paratesticular neoplasm and the most common tumor of the spermatic cord. Adenomatoid tumor is the most common tumor of the epididymis, followed by leiomyoma. In adult patients, it is imperative to consider sarcomas in the differential diagnosis of all solid tumors of the scrotum. The most common sarcomatous tumors in pediatric patients are embryonal sarcoma and rhabdomyosarcoma. Metastases, particularly from testicular, prostatic, renal, and gastrointestinal primary malignancies, can also occur. Mimics of paratesticular neoplasms including polyorchidism and splenogonadal fusion are rare but must also be considered for optimal management. Ultrasonography (US) is currently the imaging modality of choice. However, US findings are often variable and nonspecific and do not usually allow definitive characterization. Specific computed tomographic and magnetic resonance imaging findings with respect to tumor location, morphologic features, and tissue characteristics can aid in the evaluation of paratesticular neoplasms and help narrow the differential diagnosis.

Intrascrotal hemangioma

Although hemangiomas are the most common benign tumors in infancy, scrotal hemangiomas are extremely rare and comprise less than 1% of all hemangiomas. Scrotal hemangiomas that extend into adjacent areas of the perineum, thigh, or anterior abdominal wall may occasionally be seen. Ultrasound is recommended as part of the preoperative assessment delineating the extent of a scrotal hemangioma. Since an absence of flow on Doppler studies does not exclude the diagnosis of hemangioma, MRI (magnetic resonance imaging) may provide more useful information for differentiation. In cases of cutaneous scrotal hemangiomas, conservative treatment that waits for involution is widely accepted. In patients with scrotal masses, exploration with excision is the treatment of choice even if a hemangioma is likely. The authors report a case of an intrascrotal tumor diagnosed preoperatively by color duplex ultrasonography and MRI in a 19-year-old male who subsequently underwent en bloc excision. Pathological examination identified a cavernous hemangioma.