Alberto Bottini ,Alessandro De Luca ,Andrea Sagona ,Corrado Tinterri,Emilia Marrazzo,Erika Barbieri ,Federico Frusone,Giulia Puliani,Giuseppe Canavese ,Wolfgang Gatzemeier ,
Diagnosis and Clinical Management of Neuroendocrine Tumor of the Breast: Report of Six Cases and Systematic Review of Existing Literature
Annals of Clinical Oncology
2020
2674-3248
http://dx.doi.org/10.31487/j.ACO.2020.01.02
https://www.sciencerepository.org/diagnosis-and-clinical-management-of-neuroendocrine-tumor-of-the-breast_ACO-2020-1-102 
Abstract: Introduction: Neuroendocrine neoplasm of the breast (bNENs) are considered a rare disease, even if in
WHO data they represent about 2-5 % of all breast cancer. The last WHO classification includes: welldifferentiated neuroendocrine tumor (bNET), neuroendocrine carcinoma (NEC) and invasive carcinoma
with neuroendocrine differentiation. The current knowledge on clinical management of bNENs is poor and
patients are usually treated according to non-endocrine tumor components guidelines.
Materials and Methods: We presented our experience of six cases of bNENs. Moreover, we conducted a
systematic review of published data on diagnosis, treatment and outcome of this kind of tumors.
Results: bNENS usually presented as palpable breast masses, classically appearing as irregular hypoechoic
lesions at US examination and as hyperdense masses at mammography. Usually pre-operative tumor biopsy
is not able to recognize the neuroendocrine components and the final diagnosis is performed only on
definitive histopathological assessment. The most frequent subtype seems to be neuroendocrine carcinoma
and synaptophysin is positive in most specimens. Treatment strategies, including surgical treatment,
radiotherapy and medical treatment are nowadays based on current non-endocrine breast cancer guidelines,
independently from neuroendocrine components, even if some studies have proposed the use of somatostatin
analogues for bNET and cisplatin-etoposide for NEC. Prognosis of all bNENs, especially of poorly
differentiated neoplasia, seems worse compared to non-neuroendocrine breast cancer and stage and
morphology seem the best predictor of tumor outcome.
Conclusions: We provide an algorithm for clinical management of bNETs, basing on available data. More
studies are necessary for confirming the best treatment strategy for these patients, in order to improve
clinical outcomeKeywords: Neuroendocrine tumor (NET), breast, neuroendocrine carcinoma, carcinoid, neuroendocrine neoplasia