focal nodular hyperplasia


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hyperplasia

 [hi″per-pla´zhah]
abnormal increase in volume of a tissue or organ caused by the formation and growth of new normal cells. See also hypertrophy and proliferation. adj., adj hyperplas´tic.
benign prostatic hyperplasia benign prostatic hypertrophy.
cutaneous lymphoid hyperplasia a group of benign cutaneous disorders characterized by accumulations of large numbers of lymphocytes and histiocytes in the skin, which may occur as a reaction to insect bites, allergy hyposensitization injections, light, trauma, or a tattoo pigment or may be of unknown etiology.
focal nodular hyperplasia (FNH) a benign, usually asymptomatic tumor of the liver, occurring chiefly in women; it is a firm, nodular, highly vascular mass resembling cirrhosis, usually with a stellate fibrous core containing numerous small bile ducts, and having vessels lined by Kupffer cells.
nodular hyperplasia of the prostate benign prostatic hypertrophy.

focal nodular hyperplasia

A relatively common (±1% of general population) benign lesion that develops spontaneously at age 20–30, predominantly in females, and not associated with oral contraceptives. If multiple (1/3 are multiple), it may be associated with vascular defects in other organs and brain (arteriovenous malformations).

Focal nodular hyperplasia
Primary FNH
• Congenital arterial malformation.
Secondary FNH
• Acquired vascular abnormalities;
• Cirrhosis;
• Haemangioma;
• Other neoplasms;
• Venous thrombosis.
Typical FNH
• Cirrhosis-like changes;
• Chronic biliary disease with bile duct loss;
• Adjacent space-occupying lesion.
Atypical FNH
• Large cell atypia;
• Mixed hyperplastic and adenomatous;
• No central scar, especially in lesions  < 1cm;
• No prominent ductular reaction;
• Telangiectatic.

Clinical findings
Generally asymptomatic; larger lesions may undergo infarction.

Imaging
Nodular lesion with central scar.

Management
Generally conservative management; indications for surgery uncertain.
References in periodicals archive ?
Hepatocellular adenoma and focal nodular hyperplasia: value of gadoxetic acid-enhanced MR imaging in differential diagnosis.
Wu, "Diagnosis and treatment of hepatic focal nodular hyperplasia: report of 114 cases," Chinese Journal of Surgery, vol.
Molecular pathogenesis of focal nodular hyperplasia and hepatocellular adenoma.
Enhancement characteristics of hepatic focal nodular hyperplasia and its scar by dynamic magnetic resonance imaging.
Natural history of focal nodular hyperplasia of the liver: an ultrasound study.
Focal nodular hyperplasia of the liver: a clinicopathologic study and review of the literature.
Simultaneous occurrence of adenoma, focal nodular hyperplasia and hemangioma of the liver: are they derived from a common origin.
Focal Nodular Hyperplasia.--Focal nodular hyperplasia is a nonneoplastic, polyclonal lesion that manifests as a hyperplastic response of hepatocytes secondary to abnormalities in blood flow.
Magnetic resonance imaging findings of atypical focal nodular hyperplasia of the liver.
Telangiectatic focal nodular hyperplasia is a term describing typically unencapsulated, well-circumscribed, and lobulated tumors consisting of normal-appearing hepatocytes with interspersed portal tractlike structures containing arteries with thickened walls and lymphohistiocytic inflammatory infiltrates (Figures 1 through 5).
Based on the CT findings, the possibility of an atypical hepatic adenoma or focal nodular hyperplasia was initially considered but was considered unlikely.
The angiogenic substances, vascular endothelial growth factor or basic fibroblast growth factor, have been documented in endothelial neoplasms, including epithelioid hemangioendothelioma, angiosarcoma, and hemangioma.[21-24] Transforming growth factor-[Beta] has been documented within fibrolamellar carcinomas.[25] Focal nodular hyperplasia has a female predominance in most studies.