Oestrogen hormone receptors in focal nodular hyperplasia

Abstract

BACKGROUND: The role of hormones in focal nodular hyperplasia (FNH) has been investigated with conflicting results. OBJECTIVE: The aim of this study was to evaluate oestrogen and progesterone receptor immunohistochemical expression in FNH and surrounding normal liver (control material). METHODS: Biopsy materials from FNH and control tissue were investigated using an immunostainer. Receptor expression was graded as the proportion score (percentage of nuclear staining) and oestrogen receptor intensity score. RESULTS: Study material included tissue from 11 resected FNH lesions and two core biopsies in 13 patients (two male). Twelve samples showed oestrogen receptor expression. The percentage of nuclear oestrogen receptor staining was <33% in eight FNH biopsies, 34-66% in two FNH biopsies, and >67% in both core biopsies. The better staining in core biopsies relates to limitations of the staining technique imposed by the fibrous nature of larger resected FNH. Control samples from surrounding tissue were available for nine of the resected specimens and all showed oestrogen receptor expression. Progesterone receptor expression was negligible in FNH and control samples. CONCLUSIONS: By contrast with previous studies, the majority of FNH and surrounding liver in this cohort demonstrated oestrogen receptor nuclear staining. The implications of this for continued oral contraceptive use in women of reproductive age with FNH remain uncertain given the lack of consistent reported growth response to oestrogen stimulation or withdrawal.