Scrotal pathologies
Ultrasound is the primary imaging modality for evaluating the scrotum.
- Paratesticular rhabdomyosarcoma: appears on ultrasound as a large, homogeneous mass surrounding the testis. The testis itself remains centrally located and unaffected.
- Paratesticular hematoma: a consequence of trauma. Visualized as a multilocular, hypoechoic, heterogeneous structure surrounding the testis. Testicular blood flow is unimpaired.
Ovarian masses
Pelvic masses involving the ovaries in children require careful differential diagnosis.
Ovarian cysts
Simple cysts (Ovarian Cysts) are enlarged follicles. In neonates, they may be palpable in the abdomen (should be differentiated from mesenteric or urachal cysts). In adolescents, cysts form due to continued follicular growth following failed ovulation. They are usually asymptomatic but can cause an "acute abdomen" upon rupture or torsion.
- Hemorrhagic cyst: ultrasound demonstrates a blood-fluid level.
- Management: to differentiate a physiological cyst from adult-type pathologies (such as endometriosis), ultrasound is repeated in a different phase of the cycle.
Ovarian torsion
Occurs upon partial or complete rotation of the adnexa. Ultrasound reveals a markedly enlarged ovary with a fluid-debris level or septations (signs of infarction/hemorrhage). A specific sign is a hyperechoic ovary with multiple peripheral follicles.
Ovarian tumors
Malignant neoplasms account for 10% to 30% of ovarian tumors in children. These are frequently germ cell tumors.
- Teratomas and dermoid cysts: comprise two-thirds of pediatric ovarian tumors. On ultrasound (Ovarian Teratoma), they appear as a hypoechoic mass with an echogenic node (mural nodule), calcifications, and a fat-fluid level.
- Cystadenomas: large multilocular tumors. Imaging methods cannot reliably differentiate benign from malignant forms.
Presacral masses
The most common presacral pathology is sacrococcygeal germ cell teratoma (Sacrococcygeal germ cell teratoma). It is attached to the sacrum and may contain solid components.
MRI (especially sagittal planes) clearly demonstrates the intrapelvic component, which is crucial for distinguishing teratoma from anterior sacral meningocele. Teratomas can reach large sizes, obstructing vaginal delivery.
Benign variants are typically cystic with fat and calcifications, while malignant ones are solid and prone to invasion (difficult to differentiate from neuroblastoma).
Evaluation of renal blood flow in hypertension
Arterial hypertension in children is frequently secondary in nature, predominantly renovascular (e.g., due to fibromuscular dysplasia).
Diagnostic methods include:
- Ultrasound and Doppler sonography: detects vascular narrowing, polycystic changes, and scarring. Reliable signs of stenosis on color Doppler include turbulent flow with aliasing artifact and distal pulsus tardus et parvus flow.
- Magnetic resonance angiography (MRA): effective in older children for stenosis of major branches, but has low diagnostic value for distal vessels.
- Catheter angiography: the most accurate method, enabling endovascular treatment. Indicated when there is a high probability of disease and positive Doppler ultrasound findings.
Briefly: answers to topical questions
What are the types of sacrococcygeal teratomas in relation to the pelvis (Altman classification)?
Sacrococcygeal teratomas are classified according to the extent of their extension relative to the pelvic cavity. The following types of localization are distinguished:
- Intrapelvic extension (intrapelvic) — the internal component of the tumor is best visualized on sagittal MRI sections.
- Extrapelvic extension (extrapelvic) — a large presacral mass protruding beyond the perineum.
What types of malignant germ cell ovarian tumors occur in children, besides teratomas?
Aside from teratomas, several histological types of malignant ovarian germ cell tumors are identified in children.
- Dysgerminoma (dysgerminoma) — a tumor for which lactate dehydrogenase is a specific marker.
- Endodermal sinus tumor — also known as yolk sac tumor (yolk sac tumour), produces alpha-fetoprotein.
- Embryonal carcinoma — accompanied by a combined elevation of AFP and β-hCG.
- Choriocarcinoma — characterized by elevated β-hCG levels.
- Polyembryoma — also causes a combined elevation of AFP and β-hCG.
Which disorders cause renovascular hypertension in children detected on angiography?
The most frequent cause of renovascular arterial hypertension in children is fibromuscular dysplasia. The pathology is also associated with the following diseases and conditions:
- Neurofibromatosis (Neurofibromatosis) — including von Recklinghausen disease.
- Idiopathic infantile hypercalcemia.
- Arteritides — specifically Takayasu arteritis (Takayasu arteritis).
- Middle aortic syndrome (middle aortic syndrome).
- Williams syndrome (Williams syndrome).
Class and exam questions
Why is Doppler blood flow assessment less reliable in ovarian torsion?
The ovary has a dual blood supply, therefore the Doppler signal may persist even during torsion, unlike in testicular torsion.
Which diagnostic imaging method is best suited for assessing the intrapelvic component of a sacrococcygeal teratoma?
Sagittal planes are the most informative in magnetic resonance imaging (MRI).
How to distinguish an incidental (physiological) ovarian cyst from a pathological one?
A repeat ultrasound examination is recommended in a different phase of the menstrual cycle.
What else to study on this topic
- Histological types of malignant ovarian tumors in children (dysgerminoma, embryonal carcinoma, etc.)
- Differential diagnosis of presacral masses (anterior myelomeningocele, neurenteric cyst)
- Causes of secondary arterial hypertension in children
- Specifics of CT angiography (CTA) in pediatric practice
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