Invasive lobular carcinoma of the breast diagnosed from an ovarian tumour

Invasive lobular carcinoma of breast is well known to be able to metastasise to unusual places, including the gastrointestinal and gynaecological tracts. However, it is very unusual for breast cancer to present in an ovarian Brenner tumour. This case highlights the diagnostic difficulties of patients presenting with unilateral ovarian masses, and the merits of thorough histological assessment of the entire pathological specimen despite the presence of one obvious pathological diagnosis.