Summary

Breast cancer in men is uncommon, accounting for <1% of all breast cancers. Even though lobular structures are quite infrequent in the male breast, rare cases of invasive lobular breast carcinoma have been described, representing 1–2% of all breast cancers in men. Risk factors include undescended testes, congenital inguinal hernia, orchiectomy, orchitis, testicular injury, infertility and Klinefelter's syndrome, previous thoracic radiotherapy, alterations of the oestrogen–testosterone ratio and familial history (BRCA 2 and 1). The authors present a case of a 52-year-old man with no relevant predisposing factors to breast cancer, who presented with a painless, firm nodule, fixed to the nipple on the left breast, associated with nipple retraction and ulceration, and fully characterised by mammogram and ultrasound. Histopathological and immunohistochemical analysis revealed the diagnosis of invasive lobular breast carcinoma and the patient underwent left radical mastectomy, followed by adjuvant chemotherapy, radiotherapy and hormonotherapy. A brief review of the literature is presented.