Suspected focal nodular hyperplasia in male adults: 10-year experience from a large liver centre

Focal nodular hyperplasia (FNH) is commonly found in females of reproductive age. In males, the diagnosis is made more cautiously due to its lower incidence and higher incidence of hepatocellular carcinoma, which can have overlapping imaging features. Follow-up or biopsy is sometimes required. This retrospective study aims to assess management of suspected FNH in male adult patients at our institution over a 10-year period.

Male adults (≥ 18 years) suspected of having FNH from January 2010-June 2020 were identified using a departmental radiology information system search. Data was collected from radiology reports and patient pathway manager.

Of 342 patients with suspected FNH, 62 were male (18.1%; F:M of 4.5:1). We only included patients investigated and followed up by MRI, total of 57 patients. Median age was 40 years (range 18-74 years). Background liver disease present in 21/57 (36.8%), majority with hepatic steatosis. Average number of lesions per patient 1.7. 22/57 (38.6%) had at least one MRI follow-up using liver-specific contrast with 7 lesions demonstrating variation in size (range growth: -3.27 mm/year to + 4 mm/year). In 7 cases, MRI was not definitive; 6 required biopsy and 1 resection. Only 2/7 demonstrated malignancy. Of the total 57 patients, 6 have deceased and none due to a misdiagnosed or mismanaged hepatic lesion.

FNH is relatively uncommon in males, however, our data suggests that lesions with typical MRI characteristics do not require follow-up and diagnosis can be made confidently, similar to females. Any atypical features should prompt a biopsy.