Testicular cancer is responsible for approximately 0.1% of all cancer deaths in the USA, and seminoma is the most common type of testicular tumor. Ultrasonography is the primary imaging modality for accessing testicular and extratesticular lesions, while magnetic resonance imaging can be used for problem solving in lesion characterization in certain cases. CT imaging is usually performed for retroperitoneal staging of testicular cancer metastasis and follow-up after treatment. Extratesticular masses are common, yet rarely malignant. Imaging plays an important role in primary diagnosis of testicular cancer and differentiating it from common non-neoplastic findings. The purpose of this article is to review various imaging findings in testicular and extratesticular masses.

Testicular ultrasound is typically the first-line imaging examination in evaluating scrotal pathology. However, MR imaging can often provide valuable additional information, especially when ultrasound and/or clinical examinations are inconclusive. This is particularly evident when encountering testicular or paratesticular lesions, where accurate localization and characterization are paramount for management and prognosis. After reviewing normal scrotal anatomy as seen on MR imaging and offering a sample imaging protocol, the article describes specific indications for scrotal MR imaging and highlights imaging findings unique to various benign and malignant causes.

BACKGROUND: Scrotal ultrasound, though reliable in distinguishing between intratesticular and extratesticular lesions and characterizing them as cystic and solid, cannot distinguish benign from malignant pathology. Although fine needle aspiration cytology (FNAC) has proved to be of great diagnostic importance in testicular lesions, its scope in extratesticular lesions is largely unexplored.
OBJECTIVE: To evaluate extratesticular scrotal lesions cytologically and compare it with their clinical, radiological, and histological findings.
METHODS: Sixty five patients with extratesticular scrotal lesions were assessed clinically, radiologically, and cytologically. Histopathology was done in 45 cases where surgical exploration was undertaken. All the data were then analyzed and correlated.
RESULTS: Extratesticular lesions accounted for 72.2% of the scrotal swellings. Of these, the epididymis is most commonly involved (61.5% cases) with the commonest type of lesion being cystic (49.3% cases). Ultrasonography preferably with color doppler is highly useful for the evaluation of the scrotum. Apart from distinguishing extratesticular from testicular and cystic from solid lesions, it has an important role in identifying individual lesions, thus reducing the list of differential diagnosis. Fine needle aspiration cytology contributed to a definitive diagnosis in 47.7% cases. It helps classify cystic masses on the basis of their contents and defines the etiology of chronic inflammatory lesions, apart from corroborating with the clinico-radiological diagnosis. Histological evaluation was possible only in cases where surgery was performed and helps further define the diagnosis.
CONCLUSIONS: Fine needle aspiration cytology is essentially non-traumatic and easy to carry out and should be a technique of choice for the study of scrotal pathology, main advantage being avoidance of delays in diagnosis.