PURPOSE: Paratesticular rhabdomyosarcoma (RMS) represents 40% of all malignant paratesticular tumors. Nonetheless, only limited data describe the imaging features of this disease. This study aims to retrospectively review imaging findings in paratesticular RMS patients.
MATERILAS AND METHODS: A computerized search for consecutive paratesticular RMS patients was conducted between 2007 – 2016. The archived imaging studies and electronic clinical records of the paratesticular RMS patients were reviewed. Radiological examinations included ultrasound, CT, MRI and F-18 FDG PET/CT.
RESULTS: The records of 57 RMS patients were retrieved (M:F ratio 29:28). Among male patients, 7/29 (24.1%) had a paratesticular RMS. All cases demonstrated a similar sonographic appearance, most with tumor extending above the testis, a slightly heterogeneous echotexture, small cystic/necrotic areas and well demarcated borders. One tumor showed ipsilateral discrete masses in the testis and one extended to the inguinal canal. Retroperitoneal lymphatic spread routes were similar to those of testicular germ cell tumors, and lymph nodes were necrotic. Enlarged inguinal nodes were present in one case, after incomplete local intervention, due to soft tissue extension of the tumor. PET/CT showed uptake in 2/3 (66.7%), but did not alter management in our study group. MRI was helpful in differentiating between post-surgical hematoma and residual tumor, while diffusion weighted imaging (DWI) was helpful in detecting retroperitoneal lymphadenopathy.
CONCLUSION: Paratesticular RMS presents typical sonographic findings and predictable lymphatic spread. MRI can help differentiate residual tumor from post-surgery hematoma. DWI can help identify lymphadenopathy.
