Management of Rare Histological Types of Breast Tumours.

Breast tumours exhibit a wide range of morphological phenotypes, and specific histopathological types have particular prognostic and clinical characteristics. The management of uncommon premalignant and malignant lesions is often controversial due to the lack of large single-institution studies or randomised trials to define optimal treatments. In the era of frequent use of treatment guidelines, only a low level of evidence exists for the management of rare histological types of breast tumours. This review is divided into two parts: Firstly, the favourable histological subtypes like tubular, mucinous, medullary breast cancers, and phyllodes tumour (benign, borderline, and malignant) are discussed. The prognosis of these selected lesions is believed to be better than for invasive ductal carcinoma so that in some cases even less aggressive treatment should be considered. Patients with these specific histological types should be informed of this relatively favourable prognosis. Secondly, management recommendations for special situations like Paget's disease (tumour of the nipple) and inflammatory breast carcinoma are presented.