Figure 1
Scrotal US
US and MRI of metastatic paratesticular rhabdomyosarcoma
SectionUroradiology & genital male imaging
Case TypeClinical Cases
AuthorsCarcacía Hermilla I, Iglesias Castañón A, Arias González M, Sáez JL
Connected authors
16 years, male
Clinical History
We present a case of a 16 year old male with a 6 month painless testicular mass.
Imaging Findings
A 16-year-old male patient was referred for an US of a painless mass in the right hemiscrotum. The patient had no history of pain, fever or urinary tract symptoms. Physical examination by his urologist revealed a mass at the lower pole of the right hemiscrotum.
Ultrasound examination demonstrated a 4 cm right paratesticular hipoechoic mass. A small associated hydrocele was also observed. Colour Doppler ultrasound showed marked hypervascularity of the mass. The left testis and epididymis were unremarkable. On the basis of the sonographic evaluation, we thought the mass probably arose from the tail epididymis, but we recommended scrotal MRI to verify this impression.
Following sequences were performed: axial T2 TSE, axial STIR, coronal T2 TSE, coronal T1-TSE without and with gadolinium-administration. The unenhanced images revealed a well-defined mass, arising from the tail of the epidydimis. T2 sequences showed a heterogeneous mass and T1 sequences showed a mass isointense to testicular parenchyma. After gadolinium, there was a heterogeneous enhancement of the tumour. The tumor displaced the healthy testicular parenchyma. The findings were suggestive of adenomatoid tumour. Frozen section revealed a rhabdomyosarcoma. A radical orchidectomy was performed with scrotal skin resection. No lymphadenectomy was performed.
Pathology confirmed an embryonal rhabdomyosarcoma of the fusocellular type. Testis, epididymis, scrotal skin and resection edge were tumour free. Staging chest and abdominal computed tomography (CT) showed an 8 mm pulmonary nodule and retroperitoneal lymphadenopathy. A PET scan demonstrated an absence of lung neoplastic uptake but showed retroperitoneal neoplastic uptake.
Ultrasound examination demonstrated a 4 cm right paratesticular hipoechoic mass. A small associated hydrocele was also observed. Colour Doppler ultrasound showed marked hypervascularity of the mass. The left testis and epididymis were unremarkable. On the basis of the sonographic evaluation, we thought the mass probably arose from the tail epididymis, but we recommended scrotal MRI to verify this impression.
Following sequences were performed: axial T2 TSE, axial STIR, coronal T2 TSE, coronal T1-TSE without and with gadolinium-administration. The unenhanced images revealed a well-defined mass, arising from the tail of the epidydimis. T2 sequences showed a heterogeneous mass and T1 sequences showed a mass isointense to testicular parenchyma. After gadolinium, there was a heterogeneous enhancement of the tumour. The tumor displaced the healthy testicular parenchyma. The findings were suggestive of adenomatoid tumour. Frozen section revealed a rhabdomyosarcoma. A radical orchidectomy was performed with scrotal skin resection. No lymphadenectomy was performed.
Pathology confirmed an embryonal rhabdomyosarcoma of the fusocellular type. Testis, epididymis, scrotal skin and resection edge were tumour free. Staging chest and abdominal computed tomography (CT) showed an 8 mm pulmonary nodule and retroperitoneal lymphadenopathy. A PET scan demonstrated an absence of lung neoplastic uptake but showed retroperitoneal neoplastic uptake.
Discussion
Rhabdomyosarcomas are the most common soft tissue sarcomas during childhood (15% of all the pediatric neoplasias), but only 7% of them are presented in a paratesticular location. Age distribution is bimodal with a peak at 5 years and another at 16 years. The median age at diagnosis is 7 years.
Clinical symptoms include painless unilateral scrotal inflammation with no associated fever. Up to 70% of cases have retroperineal adenopathy at the time of diagnosis and 20% have distant metastases. Paratesticular rhabdomyosarcoma is usually disseminated to lymph nodes in the para-aortic and paracaval regions. The most common distant sites of metastases are cortical bone, bone marrow and lungs through haematogenous spread.
Both sonography and MRI are nonspecific since findings are similar to those found in fibrous pseudotumours and adenomatoid tumours.
The most frequent sonographic presentation in rhabdomyosarcoma is a hypoechoic solid mass. It can have a variable echogenecity due to haemorrhage and necrosis. There may or not may be an associated hydrocele. Colour Doppler US shows increase flow and low resistance.
The MRI scan study of the rhabdomyosarcoma showed a low intensity signal in T1 weighted sequences and a high intensity signal in T2 weighted sequences. The tumour was typically enhanced heterogeneously after administration of gadolinium. The multiplanar capacity of a MRI scan enables us to obtain a better evaluation of the local spread of the tumour.
A staging chest and abdominal CT using an intravenous contrast is useful in judging the extent of associated retroperitoneal and inguinal adenopathy and is the study of choice for the detection of pulmonary metastases.
The method of choice for treating paratesticular rhabdomyosarcoma is radical orchiectomy, retroperitoneal lymphadenectomy and aggressive adjuvant chemotherapy. Radioterapy is used in case of adenopathy or residual disease.
To conclude, this case illustrates the potential value of MRI to further evaluate scrotal disease when sonographic features are inconclusive or unusual. MRI evaluation may provide additional morphologic evidence to allow precise localization of the origin of the mass. Because paratesticular rhabdomyosarcoma is highly aggressive and can metastasise, early diagnosis is important. Although sonography and MRI imaging is nonspecific for characterising the disease, play an important role in local staging. CT scan is useful to evaluate distant staging and in monitoring response to therapy.
Clinical symptoms include painless unilateral scrotal inflammation with no associated fever. Up to 70% of cases have retroperineal adenopathy at the time of diagnosis and 20% have distant metastases. Paratesticular rhabdomyosarcoma is usually disseminated to lymph nodes in the para-aortic and paracaval regions. The most common distant sites of metastases are cortical bone, bone marrow and lungs through haematogenous spread.
Both sonography and MRI are nonspecific since findings are similar to those found in fibrous pseudotumours and adenomatoid tumours.
The most frequent sonographic presentation in rhabdomyosarcoma is a hypoechoic solid mass. It can have a variable echogenecity due to haemorrhage and necrosis. There may or not may be an associated hydrocele. Colour Doppler US shows increase flow and low resistance.
The MRI scan study of the rhabdomyosarcoma showed a low intensity signal in T1 weighted sequences and a high intensity signal in T2 weighted sequences. The tumour was typically enhanced heterogeneously after administration of gadolinium. The multiplanar capacity of a MRI scan enables us to obtain a better evaluation of the local spread of the tumour.
A staging chest and abdominal CT using an intravenous contrast is useful in judging the extent of associated retroperitoneal and inguinal adenopathy and is the study of choice for the detection of pulmonary metastases.
The method of choice for treating paratesticular rhabdomyosarcoma is radical orchiectomy, retroperitoneal lymphadenectomy and aggressive adjuvant chemotherapy. Radioterapy is used in case of adenopathy or residual disease.
To conclude, this case illustrates the potential value of MRI to further evaluate scrotal disease when sonographic features are inconclusive or unusual. MRI evaluation may provide additional morphologic evidence to allow precise localization of the origin of the mass. Because paratesticular rhabdomyosarcoma is highly aggressive and can metastasise, early diagnosis is important. Although sonography and MRI imaging is nonspecific for characterising the disease, play an important role in local staging. CT scan is useful to evaluate distant staging and in monitoring response to therapy.
Differential Diagnosis List
Metastatic paratesticular rhabdomyosarcoma.
Final Diagnosis
Metastatic paratesticular rhabdomyosarcoma.
References
[1] Sung T, Riedlinger WFJ, Diamond DA, and Chow JS (2006) Solid extratesticular masses in children: radiographic and pathologic correlation. AJR 186:483-90 (PMID: 16423957)
[2] Agrons GA, Wagner BJ, Lonergan GJ, Dickey GE, Kaufman MS (1997) Genitourinary rhabdomyosarcoma in children: radiologic-pathologic correlation. Radiographics. 17:919-37 (PMID: 9225391)
[3] Akbar SA, Sayyed TA, Jafri SZ, Hasteh F, Neill JS (2003) Multimodality imaging of paratesticular neoplasms and their rare mimics. Radiographics. 23:1461-76 (PMID: 14615558)
[4] Mak CW, Chou CK, Su CC, Huan SK, Chang JM (2004) Ultrasound diagnosis of paratesticular rhabdomyosarcoma. Br J Radiol. 77:250-52 (PMID: 15020370)
[5] Woodward PJ, Schwab CM, Sesterhenn IA (2003) From the archives of the AFIP: extratesticular scrotal masses: radiologic-pathologic correlation. Radiographics. 23:215-40 (PMID: 12533657)
[6] Mason BJ, Kier R (1998) Sonographic and MR imaging appearances of paratesticular rhabdomyosarcoma. AJR Am J Roentgenol. 171:523-24 (PMID: 9694492)
[7] Mora JI, Ponce A, Llopis J, Miró J (2004) Rabdomiosarcoma paratesticular. Actas Urol Esp. 28(2):245-48
Case information
| URL: | https://www.eurorad.org/case/8752 |
| DOI: | 10.1594/EURORAD/CASE.8752 |
| ISSN: | 1563-4086 |
Figure 2
Scrotal MRI
Axial T2 sequence: shows a heteogeneous mass adjacent to riht testis.
Axial STIR sequence: shows the paratesticular mass with small associated hydrocele.
Coronal T2 sequence: shows a heterogeneous mass arising from the tail of epididymis and displacing the healthy testicular parenchyma.
Coronal non-enhanced T1: shows a paratesticular mass at the lower pole of right hemiscrotum.
Coronal gadolinium-enhanced T1: a heterogeneous enhancement of the mass is observed.
Scrotal MRI
Axial T2 sequence: shows a heteogeneous mass adjacent to riht testis.
Axial STIR sequence: shows the paratesticular mass with small associated hydrocele.
Coronal T2 sequence: shows a heterogeneous mass arising from the tail of epididymis and displacing the healthy testicular parenchyma.
Coronal non-enhanced T1: shows a paratesticular mass at the lower pole of right hemiscrotum.
Coronal gadolinium-enhanced T1: a heterogeneous enhancement of the mass is observed.
