A newborn infant was found to have a large chest mass. An unenhanced CT scan through the lower thorax (figure 1) was obtained. T2-weighted MR images (figures 2,3) also are shown. What is the most likely diagnois?
Prepared by Phillip J. Haney, MD, Department of Diagnostic
Radiology, University of Maryland School of Medicine, Baltimore,
A newborn infant was found to have a large chest mass. An
unenhanced CT scan through the lower thorax (figure 1) was
obtained. T2-weighted MR images (figures 2,3) also are shown. What
is the most likely diagnosis?
Neuroblastoma is the most common of those rare solid
malignancies that may present at birth. The tumor develops in utero
when primitive neuroblastic cells fail to undergo normal regression
and differentiation. It may cause hypertension, preeclampsia,
hydrops, or hydramnios. Metastases to the placenta or umbilical
cord may occur, but spread to the maternal circulation has not been
In the case presented here, a large calcified mass was found in
the posterior right chest on the CT scan (figure 1). Up to 85
percent of neuroblastomas will be calcified on CT. The T2-weighted
MRI images (figures 2,3) show a hyperintense mass in the posterior
right hemithorax adjacent to the spine. MR images usually will
demonstrate prolonged T1 and T2 relaxation times. Additionally, the
disorder can be detected on routine prenatal sonography.
Although most congenital neuroblastomas present as adrenal
masses, thoracic and cervical tumors also may occur. An adrenal
tumor is shown in figures 4 and 5--unenhanced and enhanced CT scans
of another newborn with a palpable abdominal mass. This large
retroperitoneal mass is calcified and prevertebral in location,
contiguous to the aorta. These signs, along with involvement or
encasement of the arteries and veins, are characteristic of
neuroblastoma both in neonates and in older children. The tumor may
grow along the vascular pathways and invade the kidneys, or may
spread to retroperitoneal nodes.
Congenital neuroblastoma may present with metastases, most commonly
to the liver, bone marrow, and skin. An example of hepatic spread
is shown in figure 6. Here, there is a left neuroblastoma (N) and a
markedly enlarged liver with heterogeneous attenuation. In this
case, the large liver obscured the adrenal mass on physical
examination. The liver may be involved to such an extent that it
leads to respiratory compromise or hepatic failure.
Cystic morphology of congenital neuroblastoma is an unusual
finding and ranges from small cysts to large, thick-walled cysts
with fluid levels. Cystic metastases to the liver also may be seen.
The diffuse pattern of liver involvement shown in figure 6 is
typical for malignant involvement in the very young; older patients
tend to have nodular involvement.
Both isolated and metastatic congenital neuroblastomas have a
relatively good prognosis in infancy compared to tumors in older
children. Favorable prognostic indicators include low stage of
disease, favorable biologic markers, and histopathology compatible
with neuroblastoma in situ. Those infants with metastatic disease
tend to fall into Stage IV-S with involvement of the liver, marrow,
and skin. Overall survival varies from 60 to 90 percent with Stage
IV-S tumors, compared to 95 to 100 percent in Stage I disease.
Therapy generally consists of tumor resection only; chemotherapy is
reserved for patients with recurrent, progressive, or disseminated