Chapter 18: LIVER:BENIGN NEOPLASMS Flashcards

1
Q

BENIGN NEOPLASMS of the LIVER

A

Cavernous hemangiomas

Hepatic Adenoma

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2
Q

What are the most common benign liver tumors?

A

Cavernous hemangiomas, blood vessel tumors identical to those occurring elsewhere (see
Chapter 11 ), are the most common benign liver tumors.

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3
Q

What is the appearance cavernous hemangiomas?

A

They appear as discrete red-blue, soft
nodules, usually less than 2 cm in diameter, generally located directly beneath the capsule.

Histologically, the tumor consists of vascular channels in a bed of fibrous connective tissue (
Fig. 18-44 ).

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4
Q

What is the chief clinical significance of cavernous hemangiomas?

A

Their is that they should not be mistaken for metastatic
tumors
, and thatblind percutaneous biopsies not be performed on them.

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5
Q
A

FIGURE 18-44 Hemangioma. The photomicrograph shows the vesicular channels
embedded in fibrous stroma

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6
Q

What are hepatic adenomas?

A

Benign neoplasms developing from hepatocytes are called hepatic adenomas or liver cell
adenomas.

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7
Q

What gender is hepatic adenomas more common?

A

Although they may occur in men, hepatic adenomas most frequently occur in young
women
who haveused oral contraceptives; tumorsgenerally regress if contraceptive use is
terminated
.

The incidence of adenoma is approximately 1 in 100,000.

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8
Q

Hepatic adenomas have
clinical significance for three reasons:

A
  • (1) when they present as an intrahepatic mass they may be mistaken for the more ominous hepatocellular carcinomas;
  • (2) subcapsular adenomas have a tendency to rupture, particularly during pregnancy (under estrogen stimulation), causing lifethreatening intraperitoneal hemorrhage;
  • (3) rarely, they may transform into carcinomas, particularly, when the adenoma arises in an individual with glycogen storage disease, and adenomas in which mutations of the β-catenin gene are present.
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9
Q

What is the pathogenesis of hepatic adenoma?

A

Although hormonal stimulation is clearly associated with the development of solitary hepatic
adenoma, the causal events are unknown.

Mutations in the genes encoding the transcription
factor HNF1
α andβ-catenin have been identified in 50% and 15% of the hepatic adenomas,
respectively. [72]

Multiple hepatic adenoma (adenomatosis) syndromes can occur in individuals with maturity-onset diabetes of young (MODY3), with HNF1 mutations.

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10
Q

What is the appearance of Liver cell adenomas?

A
  • pale,
  • yellowtan, and
  • frequently bile-stained nodules,
  • found anywhere in the hepatic substance but often beneath the capsule ( Fig. 18-45A ).
  • They may reach 30 cm in diameter.
  • Although they are usually well demarcated, encapsulation might not be present.
  • The tumor commonly presents as a solitary lesion, but multiple lesions (adenomatosis) can occur.
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11
Q

What is the histological appearance of liver cell adenomas?

A

composed of sheets and cords of cells that may resemble normal hepatocytes or have some variation in cell and nuclear size ( Fig. 18-45B ).

Abundant glycogen may generate large hepatocytes with a clear cytoplasm.

Steatosis is commonly present. Portal tracts are absent; instead, prominent
solitary arterial vessels and draining veins are distributed through the substance of the tumor.

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12
Q
A

FIGURE 18-45 Liver cell adenoma. A, Resected specimen presenting as a pendulous
mass arising from the liver. B, Microscopic view showing cords of hepatocytes, with an
arterial vascular supply (arrow) and no portal tracts.

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13
Q

END

Benign tumors of the liver

A
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