Diagnostic ultrasound ( PDFDrive )

CHAPTER 54 Pediatric Pelvic Sonography 1913
Presacral Masses in Children
SOLID
Sacrococcygeal teratoma
Neuroblastoma
Rhabdomyosarcoma
Fibroma
Lipoma
Leiomyoma
Lymphoma
Hemangioendothelioma
Sacral bone tumors
FIG. 54.70 Bilateral Injections of Delux Into Ureterovesical
Junctions. This 2-year-old girl had a history of recurrent urinary tract
infection and bilateral vesicoureteral relux. Note the round, brightly
hyperechoic mounds of Delux (arrows) at the trigones bilaterally.
CYSTIC
Abscess
Rectal duplication
Hematoma
Lymphocele
Neurenteric cyst
Sacral osteomyelitis
Ulcerative colitis
Anterior meningocele
B
FIG. 54.71 Augmented Bladder. Transverse view of the bladder
(B) shows the thick wall of the anatomic bladder (straight black arrows)
and the large augmentation (curved arrows); open arrows, haustral
markings.
or obstruction, calculi, extravasation, abscess, urinoma,
hematoma, and large amounts of residual urine ater voiding. 226,227
PRESACRAL MASSES
he presacral space is a potential space between the perirectal
fascia and the ibrous coverings of the anterior sacrum. A lesion
in the presacral space can usually be identiied on routine
sonography through a distended bladder. To conirm the origin
of the mass, a water enema can be performed to identify the
rectosigmoid colon in relation to the lesion. Additional scans
through the buttocks are oten helpful to determine the true
extent of the tumor.
Sacrococcygeal teratoma is the most common presacral
neoplasm in the pediatric age group. About 50% are noted at
birth, with a 4 : 1 female-to-male incidence. Sacrococcygeal
teratoma arises from multipotential cells in Hensen nodes that
migrate caudally and come to lie within the coccyx. Radiographic
evidence of bony abnormalities of the sacrum or coccyx may be
present (Fig. 54.72). here is a 75% incidence of associated
congenital anomalies, most oten involving the musculoskeletal
system. Some sacrococcygeal teratomas are familial, with autosomal
dominant inheritance. hese teratomas have a high frequency
of twins. 228
Sacrococcygeal teratomas can be benign or malignant. Tumors
detected before age 2 months are most likely benign. hose
detected ater 2 months have a 50% to 90% incidence of malignancy.
Malignancy is more common in boys and in lesions that
are predominantly solid. Cystic lesions are more likely benign.
All teratomas have a malignant potential, regardless of their
texture, location, or size. Recurrence of a benign teratoma ater
incomplete surgical removal leads to increased risk of malignant
transformation; therefore the coccyx must be removed completely
at surgery to prevent recurrence. Sacrococcygeal teratomas can
be divided into the following four types, based on their
location:
Type I: Predominantly external
Type II: External with a substantial intrapelvic component
Type III: Small external mass with predominant intrapelvic
portion
Type IV: Entirely presacral with no external component
Type I lesions are usually benign and appear at birth. Types
II, III, and IV have a higher incidence of malignancy, probably
because the large intrapelvic component goes unrecognized and