Hyperplasia focal nodular

Hepatic lesions (adenomas, focal nodular hyperplasia, hepatocellular carcinoma, etc) Rarely, benign and malignant hepatic adenomas have been associated with the use of hormonal contraceptives. Severe abdominal pain, shock, or death may be due to rupture and hemorrhage of a liver tumor. 

B artolozzi C, Lencioni R, Paolicchi A, et al. Differentiation of hepatocellular adenoma and focal nodular hyperplasia of the liver comparison of power Doppler imaging and conventional color Doppler sonography. EurRadiol 1997 7 1410-1415. 

Oral contraceptives, estrogens, and benign liver tumors The effects of oral contraceptives on the liver include not only benign liver tumors (focal nodular hyperplasia, hepatic adenoma, and hemangioma) (74) and hepatocellular carcinoma, but also peliosis hepatis (75), sinusoid dilatation (76), and such probably unrelated shorter-term complications as jaundice and gallstones. 

Marks WH, Thompson N, Appleman H. Failure of hepatic adenomas (HCA) to regress after discontinuance of oral contraceptives. An association with focal nodular hyperplasia (FNH) and uterine leiomyoma. Ann Surg 1988 208(2) 190-5. 

Benign liver tumors (hepatocellular adenoma and focal nodular hyperplasia) are extremely rare conditions that appear to be related to oral contraceptive use (212). 

In delayed-phase imaging, the signal increase in the liver parenchyma does not necessarily increase the conspicuity or detection of lesions because residual hepatocytes of a tumor of hepatocytic origin, such as hepatocellular carcinoma (HCC) and focal nodular hyperplasia, may influence the contrast enhancement. Gd-BOPTA is effective for use with delayed-phase MRI to detect metastases [130]. In cirrhosis, liver functioning is impaired and the number of normal hepatocytes is reduced. The entry of Gd-BOPTA into cirrhotic hepatocytes decreases, but the accumulation in the liver increases due to reduced biliary excretion [131]. As a consequence, contrast enhancement is reduced and the window of acquisition is widened. The contrast enhancement of a cirrhotic liver is therefore different from that observed in normal liver parenchyma. 

The following lesions may be hypoechoic (7.) metas-tases, (2.) liver cell carcinoma, (3.) adenomas, (4.) focal nodular hyperplasia, (5.) abscesses, (6.) haematomas, (7.) early liver infarction, (S.) foci showing reduced fatty infiltration, (9.) lymphomas, and (10.) lipomas. In individual cases, differentiation between a benign and a malignant structural defect may cause considerable difficulties. (59) (s. fig. 9.4)... 

Focal nodular hyperplasia (see chapter 36.4.2) — as a benign hepatocellular tumour - is mostly hypoechoic. Occasionally, it can be differentiated as a protruding contour or a pediculate liver tumour. Compression of the surrounding liver tissue may be the cause of a visible capsule , which actually has no anatomical structure of its own. At a size of > 3 cm, fibrous septa and arteries... 

Focal nodular hyperplasia On MRI scans (as with CT), FNH shows the characteristic central venous star. Otherwise, the signal intensity of FNH is homogeneously isointense (Ti) or slightly hyperintense (T2). Immediately following the i.v. administration of CM (Gd-DTPA), a distinct but rapidly fading enhancement is observed. (65, 95, 100, 102, 110, 118)... 

In 80-90% of cases, focal nodular hyperplasia shows a typical, radial (spoke-like) arrangement of coiled vessels in the area of the tumour, which originate from a circular artery. Occasionally, fine a.v. shunts are present. The smooth-edged lesion is hypervascular. The parenchymal phase, with its homogeneous concentration of contrast medium, allows the lesion to be clearly demarcated from healthy liver tissue. (156) Hepatic adenoma is generally hypervascular. Displaced vessels are frequently visible. 

Hepatic adenomas and focal nodular hyperplasia dynamic CT study Radiology 1986 160 53-58... 

Procacd, C., Fngazzola, C., Onquino, M., Mangiante, G., Zonta, L., Bergamo Andreis, JA., NicoB, N., Rstolesi, G.F. Contribution of CT to characterization of focal nodular hyperplasia of the liver. Gastrointest. Radiol. 1992 17 63-73... 

Butch, R.J., Stark, D., Malt, R.A. Magnetic resonance imaging of hepatic focal nodular hyperplasia. J. Comput. Assist. Tomogr. 1986 10 874-877... 

Mahfonz, A.-E., Hamm, B., Taupitz, M., Wolf, K.-J. Hypervascular hver lesions differentiation of focal nodular hyperplasia from malignant tumors with dynamic gadolinum-enhanced MR imaging. Radiology 1993 186 133-138... 

Vilgrain, V., Flejou, J.-F., Arrive, L., Belghiti, J.,Najmark, D., Menu, Y., Zins, M., Vidlierme, M.-R, Nahum, H. Focal nodular hyperplasia of the hver MR imaging and pathologic correlation in 37 patients. Radiology 1992 184 699-703... 

Hepatic adenoma consists of atypical, strand-like hepa-tocytes. It is characterized by normal perfusion and an extensive absence of Kupffer cells as well as irregularity of the bile ducts. Scintigraphically, it is possible to demonstrate that there is no elimination of iminodiacetates from the adenoma and that uptake of the radioactive tracer is prolonged compared with the normal liver parenchyma ( trapping on IDA scans). (38) No colloidal albumin or Tc-colloid is taken up - this allows differentiation of an adenoma from focal nodular hyperplasia. The use of the SPECT technique increases sensitivity. 

In the case of differential diagnosis of adenoma versus focal nodular hyperplasia, scintigraphy is indicated, whereas in the case of metastases, more reliable imaging techniques are preferred, (s. fig. 9.4)... 

H. Technetium-99m DISIDA hepatobiliary agent in diagnosis of hepatocellular carcinoma, adenoma, and focal nodular hyperplasia. J. Nucl. Med. 1989 30 1278-1279... 

As regards the neoformation of benign tumours, distinction is made between nodular adenoma and focal nodular hyperplasia (FNH). Because there are several transitional types between these two forms, they are generally regarded as variants of the same basic type of tumour (H.-W. Altmann, 1980). Both types may be multiple, (s. tab. 29.10)... 

Focal nodular hyperplasia FNH is the most common benign hepatic neoplasia. As with adenoma, it may develop after the patient has taken oestrogens for a longer period (usually more than 4 or 5 years). In some cases, the lesion develops within 6 to 12 months after intake begins. (13, 125) en the oral contraceptives are discontinued, the tumour regresses or disappears (completely). The rate of both oestrogen-induced hepatocellular adenoma and FNH was considerably reduced after the introduction of low-dose oral contraceptives. 

Fig. 29.13 Focal nodular hyperplasia with parenchymal nodules between fibrotic areas resembling portal zones (same patient as in fig. 29.11)...

Evidence that focal nodular hyperplasia tends to degenerate into malignant tumours is still lacking. Hepatocellular adenomas pose the (rare) risk of developing into hepatocellular carcinoma (M. Davis et al., 1975). Several cases have been published in recent years. (44,86,119) We can add our own observation here. (s. fig. 29.14)... 

Focal nodular hyperplasia (FNH) Nodular regenerative hyperplasia (NRH) Regenerative nodes... 

Fig. 36.1 Focal nodular hyperplasia sharply dehneated, ochre-coloured, non-encapsulated, nodulated lesion with star-shaped radiating septa...

Choi, C.S., Freeny, P.C. Triphasic hehcal CT of hepatic focal nodular hyperplasia incidence of atypical findings. Amer. J. Roentg. 1998 ... 

Colle, I., Op-de-Beeck, B., Hoorens, A., Hautekeete, M. Multiple focal nodular hyperplasia. J. Gastroenterol. 1998 33 904-908... 

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