Page 649 - Textbook of Pathology, 6th Edition

numerous ducts, warranting the designation of congenital or may show slight variation in size and shape but no 633
hepatic fibrosis. mitoses. The hepatocytes in adenomas contain greater
2. SIMPLE (NON-PARASITIC) CYSTS. Simple cysts are amount of glycogen than the surrounding liver cells and
solitary non-parasitic cysts seen more frequently in middle- may sometimes show fatty change. Hepatocellular
aged women. The cyst is usually large (up to 20 cm in adenomas lack portal tracts and bile ducts but bile
diameter), lying underneath the Glisson’s capsule and filled canaliculi containing bile-plugs may be present.
with serous fluid. The cyst produces a palpable mass and Numerous blood vessels are generally present in the
may be associated with jaundice. tumour which may be thrombosed. Thrombosis leads to
infarction and may result in rupture with intraperitoneal
Histologically, the cyst wall is composed of compact haemorrhage.
fibrous tissue and is lined by low columnar to cuboid
epithelium and occasionally by squamous lining. Bile Duct Adenoma (Cholangioma)

3. HYDATID (ECHINOCOCCUS) CYSTS. Hydatid cyst Intrahepatic or extrahepatic bile duct adenoma is a rare
has already been discussed on page 616. benign tumour. The tumour may be small, composed of acini
lined by biliary epithelium and separated by variable amount
Focal Nodular Hyperplasia of connective tissue, or are larger cystadenomas having loculi
The etiology of focal nodular hyperplasia is not known but lined by biliary epithelium.
these lesions are more common in women taking oral
contraceptives. Haemangioma
Haemangioma is the commonest benign tumour of the liver.
Grossly, Focal nodular hyperplasia is a well-demarcated Majority of them are asymptomatic and discovered
tumour-like nodule occurring underneath the Glisson’s incidentally. Rarely, a haemangioma may rupture into the
capsule. The nodules may be single or multiple, peritoneal cavity.
measuring about 5 cm in diameter. It may be tan-yellow
or bile-stained. The sectioned surface shows a central MORPHOLOGIC FEATURES. Grossly, haemangiomas CHAPTER 21
fibrous scar. appear as solitary or multiple, circumscribed, red-purple
Histologically, it is composed of collagenous septa lesions, commonly subcapsular and varying from a few
radiating from the central fibrous scar which separate millimetres to a few centimetres in diameter. They are
nodules of normal hepatocytes without portal triads or commonly cavernous type giving the sectioned surface a
central hepatic veins. The fibrous septa contain prominent spongy appearance.
lymphocytic infiltrate. Histologically, haemangioma of the liver shows
characteristic large, cavernous, blood-filled spaces, lined
by a single layer of endothelium and separated by
BENIGN HEPATIC TUMOURS
connective tissue (Fig. 21.32). Some haemangiomas
These are uncommon and some of them are incidental may undergo progressive fibrosis and may later get
autopsy findings. These include hepatocellular (liver cell) calcified.
adenoma, bile duct adenoma (cholangioma) and
haemangioma. MALIGNANT HEPATIC TUMOURS

Hepatocellular (Liver Cell) Adenoma Among the primary malignant tumours of the liver, The Liver, Biliary Tract and Exocrine Pancreas
hepatocellular (liver cell) carcinoma accounts for approxi-
Adenomas arising from hepatocytes are rare and are reported mately 85% of all primary malignant tumours,
in women in reproductive age group in association with use cholangiocarcinoma for about 5-10%, and infrequently mixed
of oral contraceptives, sex hormone therapy and with pattern is seen. The remainder are rare tumours that include
pregnancy. The tumour presents as intrahepatic mass that hepatoblastoma, haemangiosarcoma (angiosarcoma) and
may be mistaken for hepatocellular carcinoma and may embryonal sarcoma. Hepatic haemangiosarcoma and
rupture causing severe intraperitoneal haemorrhage. embryonal sarcoma resemble in morphology with their
counterparts elsewhere in the body.
MORPHOLOGIC FEATURES. Grossly, the tumour
usually occurs singly but about 10% are multiple. It is Hepatocellular Carcinoma
partly or completely encapsulated and slightly lighter in
colour than adjacent liver or may be bile-stained. The Hepatocellular carcinoma (HCC) or liver cell carcinoma, also
tumours vary from a few centimetres up to 30 cm in trmed as hepatoma, is the most common primary malignant
diameter. On cut section, many of the tumours have tumour of the liver. The tumour shows marked geographic
varying degree of infarction and haemorrhage. variations in incidence which is closely related to HBV and
Histologically, liver cell adenomas are composed of sheets HCV infection in the region. Whereas the prevalence of HCC
and cords of hepatocytes which may be normal-looking is less than 1% of all autopsies in the United States and
Europe, the incidence in sub-Saharan Africa and South-East