Primary neuroendocrine carcinoma of the breast - the report of four cases.

Breast neuroendocrine tumours are rare, accounting for up to 5% of all breasts tumours and approximately 1% of all neuroendocrine tumours. In most cases, breast neuroendocrine tumours are histologically and moderately well differentiated. Neuroendocrine breast tumours lack characteristic imaging patterns. The histopathological assessment of these tumours is difficult, and in most cases the correct diagnosis is made after proper examination of the postsurgical specimen.