Para testicular rhabdomyosarcoma in adults: three case reports and review of literature

Paratesticular embryonal rhabdomyosarcoma (RMS) is a rare tumor arising from the mesenchymal tissues of the spermatic cord, epididymis, testis and testicular tunics. We report three cases of adult paratesticular RMS, two embryonic and one pleomorphic rhabdomyosarcoma. All the patients underwent diagnostic orchidectomy. The work up investigations revealed lung metastases. Chemotherapy with Ifosfamide and Doxorubicin was used in two cases, whereas Vincristin- Actinomycin D and Cyclophosphamide was received in one case. An objective partial response was reported in 2 cases, with complete response in one case. Paratesticular RMS is a rare and aggressive tumor. Because of the absence of protocols designed specifically for adult patients, it is necessary to follow therapeutic guidelines in pediatric protocols.


Introduction
Rhabdomyosarcoma (RMS) is a malignant tumor of mesenchymal origin thought to arise from cells committed to a skeletal muscle lineage. Twenty percent of all cases arise from the genitourinary system [1]. Paratesticular localization includes the epididymis or spermatic cord and occurs mostly in the young people. The first documented case of spermatic cord sarcoma was described by Lesauvage in 1845. Since this date, few cases were reported in the literature especially in adult. The treatment of these cases has evolved over the past decades because of the use of combined modality therapy. Evaluation after 6 months revealed a full disappearance of the pulmonary metastasis; the patient is monitored quarterly by a CT scan of the chest/abdomen/pelvis.

Case 2
A 19-year-old patient, presented to our oncology department, with paratesticular embryonic rhabdomyosarcoma diagnosed because a painless scrotal mass. He had undergone initially an orchidectomy.

Discussion
Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood. Its incidence is similar in Africo-American and Caucasian and appears to be lower in Asian populations. This histologic subtype develops with two peaks, the first at the age of 4 years and the second at the age of 18 years [2]. Among all cases of rhabdomyosarcoma, approximatively 7% occurs in paratestis.
Clinically paratesticular tumour presents as a hard painless inguinoscrotal swelling [3]. A hydrocele can be occasionally present in adults explaining the frequent misdiagnostic of paratesticular rhabdomyosarcoma with hydrocele in this population. In our institution, all patients had a painless scrotal mass. Regarding histologic features, embryonal RMS is predominant and represents 84% of all cases whereas alveolar and spindle cells are less frequent (8% and 5% respectively). In our serie one patient was diagnosed with embryonal RMS and two patients had pleomorphic RMS.
Spread of the tumor is mostly by lymphatics to the iliac and paraaortic nodes, but hematogenous spread does occur most commonly to the lungs and liver [4,5]. Work up investigations at diagnosis includes physical examination, chest x-ray, bilateral bone marrow smears and biopsies, abdominal and chest computed tomography (CT) scan, and bone scan [6]. Staging of paratesticular Page number not for citation purposes 3 rhabdomyosarcoma can be done according to both the tumor-nodes metastases classification and the Intergroup Rhabdomyosarcoma Study system [4]. In the literature, patients are diagnosed at localized stages in 92%. However, all cases in this study had distant metastases at diagnostic. The patients were mostly metastatic in the lungs.
Paratesticular sarcomas are rare. There is no standard treatment. In the localized disease, treatment strategies include radical high inguinal orchidectomy, retroperitoneal lymph node dissection, chemotherapy and radiotherapy [7][8][9]. Some authors recommend cyclophosphamide) and better results were observed with VAC protocol [11][12][13]. In our serie two cases received chemotherapy by MAI, and one patient was treated by VAC. The role of whole-lung RT (generally to 14.4 Gy) for patients with overt pulmonary metastases is not consensual; some protocols recommend it given the radiosensitivity of RMS. The prognosis of paratesticular rhabdomyosarcoma is extremely poor. Patients in the Intergroup Rhabdomyosarcoma Study IV had a 5-year survival rate of 22.2%.
Furthermore, age seems to be a prognostic factor with a worse prognosis in adult patients than children (with a 5-year event-free survival and 5-year overall survival of 28% and 40%, respectively [4].

Conclusion
Paratesticular RMS is a rare and aggressive tumor. In the absence of protocols designed specifically for adult patients, it is necessary to follow therapeutic guidelines in pediatric protocols. Systemic chemotherapy is essential in both early and advanced disease and has resulted in improved survival outcomes.