The role of oestrogen and progesterone receptors in gigantomastia

INTRODUCTION: Gigantomastia is a rare condition characterised by excessive breast growth. The pathophysiology of mammary enlargement varies depending on the type of gigantomastia: gestational, juvenile virginal, or idiopathic. The study aimed at examining the receptor status (oestrogen receptor α (ERα) and progesterone receptor (PR)) of breast tissue in adult women with juvenile or idiopathic gigantomastia. MATERIAL AND METHODS: The study involved 70 women who underwent breast reduction due to juvenile or idiopathic gigantomastia. Control breast specimens were obtained from 18 female cadavers. ERα and PR expressions were detected immunohistochemically in breast gland samples. RESULTS: Categorised and uncategorised ERα and PR expression did not differ between women with gigantomastia and control women. It was found that in both groups weak (0–30%) ERα and PR expression was the most common. Analysis of categorised data also did not reveal any significant correlations between ERα or PR and the women’s age: for the whole group: p = 0.795 (ERα), p = 0.207 (PR), for women with gigantomastia: p = 0.934 (ERα), p = 0.43 (PR), and for control women: p = 0.638 (ERα), p = 0.805 (PR). CONCLUSIONS: Gigantomastia is not caused by increased expression of ERα and PR. Analysing abnormal sensitivity of these receptors to hormones may be crucial in establishing the increased risk of breast cancer in women with gigantomastia.