Pediatric Rhabdomyosarcomas of the Genitourinary Tract

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in the pediatric and adolescent population, with 350 new cases diagnosed each year. While they can develop anywhere in the body, the genitourinary tract is the second most common primary location for an RMS to develop. Overall survival has improved through the increased use of protocols and multidisciplinary approaches. However, the guidelines for management continue to change as systemic and radiation therapeutics advance. Given the relative rarity of this disease compared to other non-solid childhood malignancies, healthcare providers not directly managing RMS may not be familiar with their presentation and updated management. This review aims to provide foundational knowledge of the management of RMSs with an emphasis on specific management paradigms for those arising from the genitourinary tract. The genitourinary tract is the second most common location for an RMS to develop but varies greatly in symptomology and survival depending on the organ of origin. As the clinical understanding of these tumors advances, treatment paradigms have evolved. Herein, we describe the breadth of presentations for genitourinary RMSs with diagnostic and treatment management considerations, incorporating the most recently available guidelines and societal consensus recommendations.

Case Report: Paratesticular Rhabdomyosarcoma

Paratesticular rhabdomyosarcoma (RMS) accounts for only 7% of all the RMS cases. Due to the limited available data, there is no consensus on the diagnosis and management of the paratesticular tumors. Here, we interrogated two paratesticular RMS cases in 25 and 27-year-old men presenting with painless and rapidly growing mass in the scrotum. Whereas the data showed no upregulation of tumor markers such as β-human chorionic gonadotropin (β-HCG), alpha-fetoprotein (AFP), and lactate dehydrogenase (LDH), scrotal ultrasonography and magnetic resonance imaging indicated the existence of paratesticular and inguinal lesions respectively. There was local recurrence in one patient who underwent radical orchiectomy for the sarcoma one year ago. In addition, the CT scans showed no occurrence of distant metastasis. The two patients underwent radical inguinal orchiectomy or resection of the recurrent tumors with nerve-sparing retroperitoneal lymph node dissection. Histologic examination revealed embryonal RMS (eRMS) without lymph node metastasis. We highlight the importance of multi-disciplinary participation for paratesticular RMS detection and preoperative ultrasound-guided needle biopsy (UNB) for rapid confirmatory diagnosis. Complete surgical resection coupled with chemotherapy and radiotherapy is the main treatment option for the paratesticular RMS. In addition, sperm cryopreservation treatment and endocrine follow-up could increase the overall survival and quality of life of the patients.

Robot-assisted retroperitoneal lymph node dissection: technique and initial case series of 18 patients

OBJECTIVE

To evaluate outcomes of the first 18 patients treated with robot-assisted retroperitoneal lymph node dissection (RA-RPLND) for non-seminomatous germ cell tumours (NSGCT) and paratesticular rhabdomyosarcoma (RMS) at our institution.

PATIENTS AND METHODS

Between March 2008 and May 2013, 17 patients underwent RA-RPLND for NSGCT and one for paratesticular RMS. Data were collected retrospectively on patient demographics, preoperative tumour characteristics, and perioperative outcomes including open conversion rate, lymph node (LN) yield, rate of positive LNs, operative time, estimated blood loss (EBL), and length of stay (LOS). Perioperative outcomes were compared between patients receiving primary RA-RPLND vs post-chemotherapy RA-RPLND. Medium-term outcomes of tumour recurrence rate and maintenance of antegrade ejaculation were recorded.

RESULTS

RA-RPLND was completed robotically in 15 of 18 (83%) patients. LNs were positive in eight of 18 patients (44%). The mean LN yield was 22 LNs. For cases completed robotically, the mean operative time was 329 min, EBL was 103 mL, and LOS was 2.4 days. At a mean (range) follow-up of 22 (1-58) months, there were no retroperitoneal recurrences and two of 17 (12%) patients with NSGCT had pulmonary recurrences. Antegrade ejaculation was maintained in 91% of patients with a nerve-sparing approach. Patients receiving primary RA-RPLND had shorter operative times compared with those post-chemotherapy (311 vs 369 min, P = 0.03). There was no significant difference in LN yield (22 vs 18 LNs, P = 0.34), EBL (100 vs 313 mL, P = 0.13), or LOS (2.75 vs 2.2 days, P = 0.36).

CONCLUSION

This initial selected case series of RA-RPLND shows that the procedure is safe, reproducible, and feasible for stage I-IIB NSGCT and RMS in the hands of experienced robotic surgeons. Larger studies are needed to confirm the diagnostic and therapeutic utility of this technique.

Lymph node management in patients with paratesticular rhabdomyosarcoma: a population-based analysis

BACKGROUND

Paratesticular rhabdomyosarcoma (PTRMS) is the most common primary solid tumor arising from the mesenchymal tissue of the testis. Traditionally, retroperitoneal lymph node dissection is not recommended for children aged <10 years because of the morbidity of the procedure and low risk of retroperitoneal lymph node involvement. In the current study, the authors analyzed the patient and tumor characteristics of PTRMS as well as survival outcomes associated with lymph node dissection status.

METHODS

A total of 255 cases of PTRMS were identified from the patient data reported by the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute from 1973 through 2009.

RESULTS

Among 173 patients aged ≥ 10 years, lymph node dissection was found to improve the 5-year overall survival (OS) rate from 64% to 86% (P  <  0.01). Conversely, patients aged <10 years fared extremely well regardless of lymph node dissection status; the 5-year OS rate was 100% and 97%, respectively, for patients who did versus those who did not undergo lymph node dissection (P  = .37). The yield of positive lymph nodes was approximately ≥  20% when <  11 lymph nodes were removed. The incidence of lymph node involvement was also higher in older patients compared with younger patients (40% vs 8%). Radiotherapy improved the OS rate in patients with lymph node involvement (5-year OS rate: 90% with vs 36% without radiation; P < .0001).

CONCLUSIONS

Lymph node dissection is recommended in patients aged ≥10 years. Radiotherapy is beneficial in patients with lymph node-positive disease.