Estudio diagnóstico

MASAS ABDOMINALESEN RECIEN NACIDO

La Imagenología disponible incluye:

1) Plain abdominal radiogaphy (AXR)2) Ultrasonography (US)3) Computed tomography (CT)4) Radionuclide scanning (nuclear medicine, NM)5) Intravenous urogram (IVU)6) Voiding cystourethrogram (VCUG)

+ Usually the initial imaging study + Minimal ionizing radiation + To exclude gastrointestinal obstruction or fecal masses+ Localize mass, and detect presence/absence of Ca++ + Exclude skeletal involvement, including spine

1) Plain abdominal radiography (AXR)

2) Ultrasonography (US):

+ No ionizing radiation (noninvasive) + Anatomy (solid vs. cystic, organ of origin, e.g. renal vs. extrarenal); Ca++ detection; vascularity (Doppler US) + Iodinated contrast medium not used (? role of US contrast medium in the future)+ Limitations: bone/gas artifacts, operator dependency

3) Computed tomography (CT):

+ Anatomic and morphologic characteristic of mass

+ Extent of involvement of adjacent structures + Distant foci of spread + Not limited by bone and gas + Sedation may be required (decreased with fast scanners) + Use of ionizing radiation + Use of enteral and parenteral contrast media

(iodine sensitivity may limits its use)

4) Radionuclide scanning (nuclear medicine, NM):

+ Organ (e.g. kidney) function, tissue vascularity, tumor viability

+ Magnetic resonance imaging (MRI) + No ionizing radiation + Excellent contrast resolution of soft tissues + Status of flowing vasculature may be evaluated + Best study for excluding extradural extension mass + Expensive, sedation frequently necessary (por largo

de examen), not good for Ca++ detection + Upper gastrointestinal series (UGI) + To exclude specific gastrointestinal causes, e.g.

duplication cyst, obstructive bowel lesion Barium or watersoluble iodinated contrast medium

5) Intravenous urogram (IVU):

+ Largely replaced by other modalities + Limited glomerular function in neonates limits

use + Ionizing radiation, use of parenteral contrast

medium

6) Voiding cystourethrogram (VCUG):

+ Evaluates lower urinary tract and genital masses

+ Angiography + Provides the precise segmental vascular

anatomy and for interventional procedures

(e.g. embolization)

Radiologic evaluation of an infant or child suspectedof having an abdominal mass includes(a) demonstrating the presence or absence of a

mass, and if present, the extent of the mass, (b) giving a specific pathologic diagnosis, when

possible, based on the imaging characteristics, and(c) showing tumor spread. Although the possible etiologies are numerous theradiologic data, combined with the age of the childand clinical information, will usually allow a specificdiagnosis or a very limited differential list. It isimportant to note that not all abdominal masses areclinically palpable, and not all abdominal massesneed to be imaged (e.g. splenomegaly associatedwith a viral illness or leukemia, unless specificetiology, such as a Candida abscess, is sought).

Etiologies Neonatal (birth to 1 month)

Renal (55%)

+ Hydronephrosis + Ureteropelvic junction (UPJ) obstruction + Posterior urethral valves + Vesicoureteric reflux + Ectopic ureterocele + Prunebelly syndrome + Ureterovesical junction obstruction+ Renal ectopia + Polycystic kidney disease - Autosomal dominant - Autosomal recessive + Renal vein thrombosis + Mesoblastic nephroma + Wilms' tumor + Abscess


Genital (15%) + Hydrometrocolpos + Ovarian mass + Simple cyst + Torsion + Teratoma

Gastrointestinal (15%) + Duplication cyst +Volvulus+ Complicated meconium ileus+ Mesenteric/omental cyst+ Bowel atresia with proximal cystic dilatation+ Hypertrophic pyloric stenosis+ Gastric teratoma


Nonrenal retroperitoneal (10%) + Adrenal hemorrhage + Neuroblastoma+ Teratoma + Rhabdomyosarcoma+ Lymphangioma + Hemangioma+ Lipoma + Anterior meningocele

Hepatobiliary (5%) + Metastases + Hemangioendothelioma

+ Hepatoblastoma + Mesenchymal hamartoma

+ Simple cyst of the liver

+ Hematoma of the liver

+ Choledochal cyst + Hydrops of gallbladder

Nonrenal retroperitoneal (10%)Adrenal hemorrhageNeuroblastomaTeratomaRhabdomyosarcomaLymphangiomaHemangiomaLipomaAnterior meningoceleHepatobiliary (5%)

MetastasesHemangioendotheliomaHepatoblastomaMesenchymal hamartomaSimple cyst of the liverHematoma of the liverCholedochal cystHydrops of gallbladder

ALGORITMO MASAS ABDOMINALES















Caso Clínico (1)

Initial AXR is unremarkable with a nonobstructive bowel gas pattern.

Ultrasound examination shows a multicystic mass inthe right renal fossa and a normal left kidney. Notethat the cysts are not communicating with each other(unlike the hydronephrosis) and are arranged in ahaphazard fashion (unlike hydronephrosis wherecalyces are radiating from the central renal pelvis).

Caso Clínico (2)

Diagnosis is multicystic dysplastic kidney (MCDK).

VCUG performed to exclude distal obstructive

pathology and associated renal anomalies (higher

prevalence) shows vesicoureteric reflux up the distal

left ureter (grade 1 reflux). In this classic

infundibulopelvic type of multicystic dysplastic kidney

(MCDK), the ureter is atretic and there is absence of

blood supply to the kidney.

Caso Clínico (3)

Multicystic dysplastic kidney is one of the commonest

causes for a neonatal abdominal mass. Bilateral

involvement is incompatible with life, associated with

severe pulmonary hypoplasia and maternal

oligohydramnios. Most MCDK are left alone, and they

often become smaller, although some remain the

same size or even grow on follow up. If renal

scintigraphy is performed, MCD kidney will show no

uptake or excretory function.









Health & Medicine

Estudio diagnóstico