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Radiology
Case of the Month
| Case No. : | 11 |
| Month : | November |
| Year : | 1999 |
| Contributor : | Dr. Gajanan Chavan |
An 18 month old girl presented to our pediatric out-patient services with an epigastric lump. The lump was first noticed by the father accidentally when the girl was about 8 months old. At that time it was of the size of a walnut; and since then it has been progressively increasing in size over a period of one year.
On examination, a firm lump was palpable in the epigastrium arising from the left lobe of the liver, measuring about 8 cm in diameter. It was non tender, non pulsatile, and without any bruit. There was no local warmth.
The baseline blood investigations were normal. Alpha-feto protein levels were not elevated.
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Fig 1 : A chest film
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| Fig 2A & 2B : Pre and post contrast CT scans of the abdomen. | |
The chest radiograph reveals cardiomegaly and speckled calcification over the epigastrium. Ultrasonography of the abdomen (not shown) showed a heterogeneous mass in the left lobe of liver, 7cm in diameter, with many anechoic areas and irregular contours. There were scattered areas of calcification within the mass.
The CT scan of the abdomen shows a mass adjacent to left lobe of liver extending superiorly upto the diaphragm and inferiorly to the level of pancreas with calcification and peripheral enhancement in the post contrast scan. There was no obvious lymphadenopathy or free fluid. The rest of the liver, spleen, both kidneys and pancreas were unremarkable. Based on the imaging findings and the clinical presentation a differential diagnosis of hemangioendothelioma and mesenchymal hamartoma was suggested..
Operative and Pathological Diagnosis:
At surgery, there was a highly vascular mass measuring 10 cm x 7cm x 7cm, arising exophytically from the left lobe of liver, adherent to parietal peritoneum and receiving blood supply from liver. On frozen sections, there was a suspicion of mesenchymal hamartoma or hemangioendothelioma. The mass was resected and final histopathological diagnosis was an infantile hemangioendothelioma.
Tumors of liver in neonates and infants can be benign or malignant. The common benign liver tumors are hemangioma and infantile hemangioendothelioma. Infantile hemangioendothelioma is the commonest liver neoplasm encountered within first six months of life and 45% of cases are associated with cutaneous hemangioma. Infantile hemangioendothelioma is found more commonly in girls than in boys in the ratio of 2 : 1. It may be single or multiple, focal or diffuse, noncapsulated ranging from 1-15cm mainly involving the portal area. On histopathology, Dehner classified these tumors into two types :
- Benign: Proliferation of the vessel by a single layer of endothelial cells and the center of the lesion includes cavernous areas, causing pudding on angiography.
- Malignant : Hyperchromatic endothelial cells with more pleomorphic & multilayered lining with budding and branching patterns.
Over 85% of the affected children present in the first six months of life. Patients can present with a lump in upper abdomen, pain in right hypochondrium; tachypnea, cutaneous hemangiomas, petechial hemorrhages and jaundice. As a result of complications such as haemoperitoneum, patients may go into shock. A baby presenting with pronounced hepatomegaly and congestive cardiac failure in the absence of physical finding of primary cardiac disease is strongly indicative of hemangiomatous tumor of liver.
Secondary to coagulopathy, there may be decrease in platelet count and increase in bleeding time, clotting time. In an infantile hemangioendothelioma arising from the
liver, the alpha feto-protein is usually normal - though rarely it may elevated.
Usually chest radiograph shows cardiomegaly and fine speckled calcification in relation to liver is seen on abdomen radiograph. Ultrasound examination usually reveals single or multiple, diffuse hypoechoic or hyperechoic lesions in the liver. Occasionally, the
lesions may show streaky or even anechoic channels with calcification.
Doppler examination shows blood flow from liver with increased velocity. There is a frequency shift of 3 KHz which is higher than hemangioma but lower than hepatocellular carcinoma. Usually, there is an increase in the diameter of aorta above celiac axis.
Nuclear scans show increase in blood flow seen on blood pool phase with increased flow pattern in lesion and defects seen on technetium-99m sulphur colloid scan.
The CT scan gives the exact size and spread of lesion. Non contrast CT scan usually shows homogenous or inhomogeneous low attenuation lesion with tiny tumoral calcification. Dynamic contrast study gives early peripheral enhancement known as iris effect and progressive opacification of central part in delayed scan at about 20 minutes.
On angiography, there is a hyper vascular mass in the liver which shows feeding vessels which are stretched, distorted and fail to taper; there is pudding of contrast with early draining veins as a result of A-V shunting.
On MR imaging, T1 weighted images show inhomogeneous hypo intense lesion and T2 weighted images show inhomogeneous hyper intense lesion in the liver.
The management of these patients depends upon symptoms. If a patient is asymptomatic, then no treatment is required. But rarely, when patient presents with cardiac failure, hemoperitoneum, shock secondary to rupture of infantile hemangioendothelioma, they require urgent and quick management. When the patient does not respond to medical line of treatment for congestive cardiac failure, he can be treated with therapeutic embolisation using polyvinyl alcohol or detachable silicon balloon or by surgical hepatic artery ligation.
Usually infantile hemangioendothelioma resolves on its own within 2 years.
Cavernous hemangioma :
Rarely present in infancy, it is the most common primary liver tumor in older age group and usually associated with other hemangiomas in the body. Cavernous hemangioma rarely presents as congestive cardiac failure. Ultrasonography shows solitary echogenic mass or multiple poorly reflective defect with scattered internal echoes. CT scan shows hypodense lesion with peripheral enhancement with subsequent variable opacification of the central part of hemangioma, this is known as iris effect and is diagnostic. On angiography a well circumscribed mass, pooling of contrast saccules for more than 20 seconds with normally tapering vessels.
Hepatoblastoma :
This is the most common symptomatic malignant tumour presenting before the age of 5 years. It may be single or multiple and commonly involves the right lobe of the liver. Usually, child presents with abdominal mass, is severely ill with weight loss, anorexia, pallor and weakness. Usually, the alpha feto-protein and HCG levels are elevated. Plain films show hepatomegaly or soft tissue mass with a different pattern of calcification. USG shows hyperechoic inhomogeneous mass with hypoechoic areas within it secondary to necrosis and hemorrhage. USG also shows ascites, impression over adjacent structures such as the kidney and IVC. Duplex doppler sonography shows high velocity flow with frequency shift of 5 KHz in the hepatic artery - much higher than infantile hemangioendothelioma. A CT scan is a good preoperative modality to see the site, lobar extension of tumor in the liver and metastasis. CT scans show non enhancing, hypodense mass with variable calcification. Angiography shows hypervascular mass, stretching of intrahepatic vessels and puddling of contrast - but there is no early draining vein suggestive of AV shunting.
Mesenchymal Harmartoma :
This is thought to be a developmental anomaly rather than a true neoplasm. Usually, the patient presents with abdominal distension, fever, vomiting and constipation. The alpha feto-protein levels are within normal limits. Plain films show a soft tissue mass. USG shows a predominantly cystic mass with multiple echogenic septae. CT and MR imaging show a predominantly cystic mass of water attenuation with internal septae. Angiography shows an avascular to hypovascular mass with variable displacement of adjacent vascular and non vascular structures.