FINDINGS AND PROCEDURE DETAILS :
This pictorial review depicts the CT scan findings of various abdominal masses in pediatric patients scanned at our center demonstrating organ involvement,
its confinement,
local extension,
distant metastasis and response to therapy.
Here we are going to share cases from our department illustrating wide spectrum of lesions involving liver,
biliary channels,
pancreas and kidneys,
miscellaneous.
All cases were confirmed on histopathology later .
The scanning was performed on 16 and 64 slicer Toshiba Aquilion scanner respectively with 120KV and 150mAs ,
slice thickness of 5mm from diaphragm upto pelvis.
Interpretation of CT scan will be done by senior radiologist on CT workstation having minimum 5 years experience.
HEPATIC MASSES:
Hepatic masses comprises approximately 5-6% of all intra-abdominal masses in children [1].
Based on age of child ,
clinical scenario and imaging patterns differential diagnosis of liver tumors in children can be made.
Majority of liver tumors are malignant.
Only 1/3rd of the liver tumors are benign [1 ]
1. HEPATOBLASTOMA:
It is most common hepatic malignancy seen in patients less than 3 years of age.
ON CT scan well defined heterogeneously enhancing mass in liver with chunky dense calcific foci.
It also aids in detection of pulmonary metastasis.
2. Hemangoendothelioma:
Usually seen in patients with less than 6 months of age with heart failure as an spectrum of hyperdyanmic state.
They behave similar to hemangioma elsewhere in the body with classic peripheral nodular enhancement and gradual filling-in.
There is reduced caliber of infraceliac aorta because of increased flow to the liver.
3. HYDATID CYST:
It is infrequently seen in pediatric population,
most common location is liver(70%) followed by lungs(20%).
Imaging appearances can be varied unilocular simple cyst with no internal architecture .
Multilocular vesicular cystic hypodense areas with internal debris.cysts with daughter cysts and calcification.
PANCREATIC MASSES:
1. PSUEDOCYST:
Pancreatic pseudocyst are most common cystic masses usually seen as a sequelae of acute,
chronic pancreatitis or secondary to trauma.
Children with leukemia receiving asparaginase therapy usually develop pancreatitis as a complication and thus the psuedocyst.
Differentiation from other cystic masses is very important for exact management in this region.
2. PANCREATOBLASTOMA: Pancreatoblastoma is most common primary pancreatic neoplasm of childhood accounts for 0.5% of all exocrine tumors.
Tumor has propensity to affect male population especially of Asian ethnicity More than two-thirds of cases shows raised alpha-fetoprotein levels as seen in other blastomas.
BILIARY TRACT MASSES:
1. Choledochal cyst:
Congenital choledochal cysts are anomalies involving cystic dilatation of any segment of the biliary tract,
and are most frequently identified in the common bile duct.
The clinical presentation of such condition is characterized by a triad of signs and symptoms including abdominal pain,
presence of palpable mass and jaundice [6].
An accurate diagnosis is hardly achieved because this triad presents in only one third of patients[7]..
2. CAROLI DISEASE:
Congenital condition having autosomal recessive inheritance due to ductal plate abnormalities.
Medullary sponge kidney,
Ehler danlos syndorome and autosomal recessive kidney disease are well known associations..
RENAL ORIGIN:
1. WILMS TUMOR:
Nephroblastoma is more commonly known as a Wilms tumour after Dr Max Wilms,
the German surgeon who first described it in 1899.
In childhood it is the most common renal malignancy and accounts overall for 6% of malignancies in children [8].
Syndromic associations include Patau,
Edward ,
Beckwith-Weidemann syndromes ( triad of gigantism,
macroglossia,
omphalocoele and genitourinary abnormalities,
with an abnormal WT2 gene on 11p15).
Wilms seen in 10-20% of cases and Drash syndromes (ambiguous genitalia and glomerulonephritis in genotypic males,
with an abnormal WT1 gene on 11p13).
2. MULTILOCULAR CYSTIC NEPHROMA:
Benign mesenchymal tumor and epithelial tumor of kidney with bimodal age predilection.
It has propensity to involve renal pelvis.
On CT a multiseptated well defined mass with hypo attenuated areas.
Sepate shows variable enhancement.
Usually no solid component seen.
3. URINOMA:
Collection of urine in perirenal space secondary to urinary obstruction or trauma.
CT abdomen with contrast delayed pahse and CT cystogram are the investigation of choice.
Other studies like intravenous pyelogram ,retrograde urethrogram (RUG) and ultrasound guided aspiration are supplementary investigation.
OVARIAN TUMORS:
These tumors are commonly seen in post pubertal girls presented as pain ,
abdominal distension and dragging ache.
Based on histology categorized into epithelial tumors,
germ cell tumors and stromal tumors.
Usual imaging appearance are huge cystic ,
solid cum predominantly cystic ( multiloculated or unilocular) masses.
Few may present as solid entities.
MISCELLANIOUS:
1. NEUROBLASTOMA:
Neuroblastoma (NBL) is the most common solid extra-cranial tumour in childhood [9].
It occurs along the course of sympathetic chain derived from neural crest cells.
Frequently contain calcification and crossing the midline compared to wilms tumor.
Mean age of presentation is 22 months.
2. Klippel-Trenaunay syndrome (KTS)
Comprises of triad of abnormalities hypertrophy (bony and soft tissues),
cutaneous small capillary hermangiomas,
port wine stains and congenital lympho-venous malformation.
Less than 1000 reported cases,
usually involve one limb.
3. SACROCOCCYGEAL TERATOMA:
It is very rare tumor composed of all three germ layers.
Usually detected prenatally due to its huge size.
Female gender is more commonly affected presented with bladder/bowel dysfunction.
Alpha-fetoprotein is considered as tumor marker.
4.
CHEST/ABDOMINAL WALL HEMANGIOMA:
Hemangiomas are benign vascular tumors comprises dilated thin walled vessels.
They can be locally aggressive least commonly involving chest wall.
Typically seen in children may involute with time.
Face is involved followed by trunk.
4. LYMPHANGIOMA:
These are dilated lymphatic channels,
which can be cloudy or clear,
uni or multilocular,
very soft with plicated wall.
Differentiation from ascites is usually a bit difficult if these lesions are very large.
It doesn’t creep into small spaces as ascites does.
CT will demonstrate masses with water density.
Septa are less well seen than on ultrasound.
After hemorrhage they can even appear solid.
The MRI characteristics depend on the absence or presence of bleeding or infection.
Uncomplicated cysts are low on T1 and high on T2,
but these signals are variable after bleeding.