PEDIATRICS: BLADDER & TESTIS ONCOLOGY
Rhabdomyosarcoma (RMS)
- Epidemiology
- Most common soft-tissue sarcoma in children
- Genetics
- Most cases are considered to be sporadic
- Genetic syndromes associated with RMS:
- Li-Fraumeni syndrome
- Neurofibromatosis
- Basal cell nevus syndrome
- Costello syndrome
- Noonan syndrome
- Multiple endocrine neoplasia type 2A
- Pathology and molecular biology
- Histologic categories (3):
- Embryonal
- Most common form of bladder or prostate RMS.
- Alveolar
- Uncommon in the bladder or prostate
- Two distinct types, PAX-FOXO1 fusion positive and negative, and fusion-positive tumors carry a worse prognosis
- Undifferentiated
- Management
- Radical surgery may be required if there is lack of response to non-operative treatment.
- Prognosis
- Prognostic factors
- Site of origin
- Prostate has the worst prognosis
- Vaginal has best prognosis
- Histology
- Embryonal histology associated with improved prognosis compared to alveolar
Urothelial carcinoma of the Bladder
- Uncommon
- Lesions are unifocal, typically low grade and not prone to recurrence
- Management
- Treatment consisting of resection only is adequate. Adjuvant treatment is not given.
- Surveillance cystoscopy is not needed; ultrasound is remarkably accurate and is an adequate surveillance strategy
Female Genital Tract
Testicular Tumors
- More likely benign in pre-pubertal males (in contrast to post-pubertal males where most testicular tumours are malignant)
- Epidemiology
- The most common pathologic diagnosis in children with a testicular mass is a YST, followed by teratoma
- Germ Cell Tumors
- Pathology
- Tertatoma
- According to some series, teratomas are the most common testicular tumor in children and consist of variable combinations of the three primitive embryologic germ cell layers [contradicts above]
- Consist of variable combinations of the three primitive embryologic germ cell layers
- Do not express AFP
- In contrast to teratoms in post-pubertal males, most teratomoas in pre-pubertal male are benign, consisting of mature elements only, and do not metastasize
- Preferred treatment for suspected teratoma is partial orchiectomy
- Epidermoid cysts
- Benign lesion; represent a monolayer teratoma
- May account for >15% of prepubertal testis lesions
- Do not express AFP
- Preferred treatment for suspected epidermoid cysts is partial orchiectomy
- No surveillance is required after treatment
- Yolk-sac tumour (YST)
- Pathology
- Schiller-Duval bodies consist of a central blood vessel surrounded by two layers of tumor cells
- AFP levels are elevated
- When metastases occur, YSTs often exhibit hematogenous spread to the lungs, without retroperitoneal disease. For these reasons retroperitoneal lymph node dissection (RPLND) plays very little role in pre-pubertal YST.
- RPLND is used exclusively for patients with a residual retroperitoneal mass or persistently elevated AFP after chemotherapy and orchiectomy
- Presentation, Evaluation, and Staging
- See CW11 Figure 156-7
- Ultrasonography
- Teratomas
- Heterogeneous complex lesions and may contain cystic and solid components.
- Bony elements appear as calcifications with shadowing.
- Adipose tissue appears as echogenic areas without shadowing.
- Epidermoid cysts
- Characteristic appearance described as “onion skin” comprised of concentric rings of alternating hypoechoic and hyperechoic lesions.
- YSTs
- Typically well circumscribed and heterogeneous in appearance.
- May appear hypervascular and may have areas of hemorrhage and necrosis.
- Sertoli and Leydig cell tumors
- Similar in appearance
- Commonly manifest as a well-circumscribed hypoechoic mass.
- Labs
- Tumour markers
- Interpretation of AFP levels in infants undergoing evaluation for a testis mass must be performed with caution as a result of the physiologically persistent elevation of AFP in infants age < 1
- Tumors Associated with Disorders of Sexual Differentiation
- Gonadal Stromal Tumors
- Juvenile granulosa cell tumors
- Most common testicular tumors affecting neonates
- Leydig cell tumors
- Hormonally active; associated with precocious puberty.
- Sertoli cell
- Usual presentation is a painless mass
- Associated with endocrinologic and genetic syndromes such as Peutz-Jeghers and Carney syndromes
- 10% are hormonally active
- Leukemia and Lymphoma
- The most common cancers with metastases to the testis are leukemia and lymphoma
Paratesticular Rhabdomyosarcoma
- Arises from the testicular tunicae, epididymis, or spermatic cord.
- Up to 40% of paratesticular lesions are due to RMS
- Management
- Multimodal involving surgery and chemotherapy with vincristine, dactinomycin, and cyclophosphamide
- Children age > 10 should undergo a staging ipsilateral retroperitoneal lymph node dissection, and not observation, because of a high occurrence of retroperitoneal failure
References
- Wein AJ, Kavoussi LR, Partin AW, Peters CA (eds): CAMPBELL-WALSH UROLOGY, ed 11. Philadelphia, Elsevier, 2015, vol 4, chap 156
