Baylor University Medical Center Proceedings April 2017 - 206

Table 1. Summary of clinical presentation and treatment of 7 patients with renal primitive neuroectodermal tumor
Clinical
Case Age Sex presentation

CT imaging
F Incidental
Localized
Hypodense enhancing
detection durlesion in right kidney,
ing antenatal
infiltrating the collecting
checkup
system (Fig. 1)
F Abdominal
Localized
Mass lesion 20 × 13 ×
lump for
13 cm in right kidney
2 months
with calcification,
infiltrating right lobe of
liver (Fig. 3)
F Left hypoMetastatic: Mass lesion 18 × 10 ×
chondrial
orbit (Fig. 4) 13 cm in left kidney with
pain, diplopia,
multiple hypodensities
ptosis
and calcifications
F Abdominal
Metastatic: NA
pain and lump; bone
presented after
nephrectomy
M Backache;
Metastatic: Heterogeneously enhancing
presented
lung, bone, hypodense lesion 8.3 ×
after
liver
6.6 cm in lower half of right
nephrectomy
kidney
M Abdominal
Localized
Heterogeneously enhanclump
ing mass lesion 10 × 7 ×
10 cm in right kidney with
calcification
M Flank pain;
Metastatic: NA
presented after lungs
nephrectomy
Extent

Immunohistochemistry
Surgery
CK-, LCA-,
Radical
SNP-, CG-, CD99 nephrectomy
strong+ (Fig. 2)
after cesarian
section
LCA-, PAX5-,Tdt, Radical
CD5-, Des-,
nephrectomy
CD99+, SNP+
at 12 wk of
chemo (margin
positive)
SNP-, CD99+
Renal biopsy
only

Chemotherapy Radiation
Status
VDC/IE
No
Alive in
17 cycles
remission
at 15 mo
VDC/IE
45 Gy
10 cycles

Died at
15 mo due
to sepsis

VDC/IE
20 Gy
13 cycles (orbit)

Progression
at 18 mo

Radical
VDC
nephrectomy 6 cycles

20 Gy
(bone)

Progression
at 6 mo,
BSC

CD99+, Vim+,
Radical
No
CK-, S100-, Des-, nephrectomy
CD10-

20 Gy
(bone)

2 mo, BSC

CD99+, SNP
focally+, CG-

Radical
No
nephrectomy

Lost to
follow-up
after surgery

CD 99+, NSE+,
LCA-

Radical
VDC
nephrectomy 9 cycles

Progression
at 14 mo

BSC indicates best supportive care; CG, chromogranin; CK, cytokeratin; Des, Desmin; IE, ifosfamide, etoposide; LCA, leukocyte common antigen; NSE,
neuron-specific enolase; SNP, synaptophysin; Tdt, terminal deoxynucleotidyl transferase; VDC, vincristine, doxorubicin, cyclophosphamide; Vim, vimentin.

Figure 1. (a) Plain CT scan of the abdomen, axial view, showing a large isodense
lesion involving the right kidney causing contour distortion and enlargement.
(b) Contrast-enhanced CT image showing moderately enhancing nonhomogeneous mass with involvement of the collecting system and infiltration of the right
psoas muscle. (c) Plain CT coronal section showing enlargement of the right
kidney with loss of fat plane with right lobe of liver.
206

such tumors is often 10 cm (7, 8). Systemic symptoms such
as weight loss and fever may also occur (9). Our patients presented similarly, except in one patient in whom the renal mass
was detected during antenatal checkup. Most of the patients
present at an advanced stage with distant metastasis, which is in
concordance with the aggressive behavior of this tumor (4, 10).
Common sites of metastasis include the lung, liver, and bone
(6). In our series, 4 out of 7 had metastatic disease at presentation involving the lungs and bone.
The imaging characteristics of renal PNET are often nonspeciﬁc and overlap with those of other renal tumors, such as
renal cell carcinoma, Wilms tumor, neuroblastoma, lymphoma,
and desmoplastic small round cell tumor (11). Renal PNETs appear hypoechoic, isoechoic, and ⁄or hyperechoic to the adjacent
renal parenchyma on ultrasound and show increased vascularity on Doppler imaging. CT scan shows a large heterogenous
mass with areas of hemorrhage or necrosis (12). On magnetic
resonance imaging (MRI), the tumor appears as a lobulated
isointense and ⁄or hypointense mass on T1-weighted images
and as a heterogeneous to hyperintense mass on T2-weighted
images, with heterogenous contrast enhancement (6, 12). MRI
and CT also help to evaluate renal vein and inferior vena caval

Baylor University Medical Center Proceedings

Volume 30, Number 2

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