Focal Nodular Hyperplasia of the Liver

Radiologic-Pathologic Correlation

Abstract Introduction Clinical Features

Pathologic Features Radiologic Features Differential Diagnosis Treatment And Prognosis

Summary Source Information References

Treatment And Prognosis

FNH is a benign tumor with no malignant potential that does not necessarily require surgical excision. In symptomatic patients, however, the lesion can usually be easily and completely excised. Only a single case of recurrence after resection has been reported (39). Discontinuation of oral contraceptive use has been recommended for women, regardless of whether they are symptomatic. Regression may occur, but it is unusual (15,40).

In cases in which the diagnosis of FNH is uncertain because of the lack of characteristic imaging findings, biopsy may be necessary. Findings from open biopsy are diagnostic in most cases. Needle biopsy findings are more difficult to interpret, but they are usually diagnostic when the pathologist has experience with hepatic pathology. For example, hepatic pathologists at the AFIP are frequently consulted to make a definitive diagnosis from needle biopsy specimens. Therefore, the type of biopsy performed should be chosen on the basis of the requirements and expertise of the pathologist who will be interpreting the specimen. Suboptimal samples obtained at needle biopsies must, however, be interpreted with caution. If only proliferating hepatocytes without the associated central scar or fibrous septa are noted, differentiation of FNH from hepatocellular adenoma and well-differentiated hepatocellular carcinoma may be impossible. On the other hand, if only fibrous septa and bile ducts are noted, distinguishing FNH from cirrhosis is often difficult. If needle biopsy is performed, it is imperative to obtain adequate samples of the peripheral cellular portions of the tumor as well as of the central scar. If biopsy results are inconclusive, resection should be considered.

In cases in which the imaging findings are strongly supportive of FNH, biopsy may not be necessary. Whether follow-up studies are required in this situation is debatable. We believe that follow-up is not necessary when the appearance of the lesion is classic for FNH, for example, when uptake is demonstrated on sulfur colloid images or when the lesion is essentially isointense relative to the liver on all MR images regardless of the pulse sequence used. If follow-up studies are considered necessary to ensure the stability of the lesion, 3-month, 6-month, 1-year, and 2-year follow-up examinations are reasonable.

Abstract Introduction Clinical Features

Pathologic Features Radiologic Features Differential Diagnosis Treatment And Prognosis

Summary Source Information References