Evaluation of Testicular Nonseminomatous Germ Cell Tumor Using Contrast-Enhanced Ultrasound

Abstract

Ultrasound is the first-line and established imaging modality for the diagnosis of testicular masses and neoplasms, with high sensitivity. Conventional ultrasound can very reliably detect presence of an intratesticular mass although it may not specifically characterize them as benign or malignant and neoplastic or nonneoplastic or classify the type or subtype of neoplasm in every case. Contrast-enhanced ultrasound (CEUS) is a technique in which injected intravenous microbubbles can supplement the characterization of focal testicular masses through observation of real-time perfusion of the testis and the target mass. Testicular masses have been documented to demonstrate unique enhancing patterns on CEUS. We report a unique case involving a young male presenting with a palpable testicular mass in which CEUS aided in the diagnosis of testicular germ cell tumor. The diagnosis was subsequently confirmed by histopathological examination after surgery. This case report highlights the utility of CEUS as a useful complementary adjunct in diagnosing and characterizing nonseminomatous germ cell tumors of the testes with a review of the literature.

Keywords: CEUS; case report; contrast ultrasound; perflutren microbubbles; testicular neoplasm.

Figure 1

B-mode ultrasound reveals a well-circumscribed intratesticular mass lesion involving the left testicular parenchyma in the inferior aspect. The lesion is heterogeneous and predominantly solid with several small cystic spaces.

Figure 2

Marked intralesional vascularity and hyperemia on microflow imaging (MFI), a form of power Doppler imaging, in which vessels are seen as bright lines (thin long arrow). The image also depicts the typical curved and haphazard (short thick arrow) course of the vessels.

Figure 3

Contrast-enhanced ultrasound image of the lesion using perflutren microbubbles in the late arterial phase. The bubbles within intralesional vessels are bright echoes, whereas avascular areas remain dark or anechoic and represent cystic spaces or necrotic areas. The typical enhancing “twisted vessels” (thin long arrow) are identified within the tumor. The peripheral rim enhancement (short thick arrow) is also appreciated. Early wash-in and early wash-out of contrast were observed.

Figure 4

(a–d) Photomicrography of histopathological evaluation of the testicular mass. The tumor comprised 50% embryonal carcinoma (a), 20% yolk sac tumor (b), 20% mature teratoma (c), and 10% choriocarcinoma (d). This appearance confirmed a nonseminomatous germ cell tumor of mixed cell type. Pathological staging was pT3 (pTNM, AJCC eighth edition). Credit for histological images: Dr. Mrinal Kishor Mallya, MD, DNB, consultant histopathologist, P.D. Hinduja National Hospital, Mumbai, India.