Small cell carcinoma of the breast resembles small cell carcinoma of the lung morphologically and immunohistochemically. Many hypotheses have tried to explain the histogenesis of neuroendocrine cells in mammary tissues; the most recent explanation is that NEBC are derived from divergent differentiation of a neoplastic stem cell into both epithelial and neuroendocrine cells (7). Two other old hypotheses suggested that it is either derived from neural crest cells that migrate to mammary glands, (12) or that it originates from neuroendocrine cells present in the breast tissue.
Many reports have addressed the prognosis of NEBC with conflicting observations, where some observed that it may be less aggressive than the usual invasive ductal carcinoma subtype (IDC) (1) (13), and others concluded that invasive neuroendocrine carcinoma of the breast has a poorer prognosis (14) than IDC. High nuclear grade, large tumor size, and regional lymph node metastasis were significant negative prognostic factors for distant recurrence-free survival (14). Others reported that NEBC has the same prognosis as other invasive breast cancers and is dependent on the staging, grading, mucin production and apocrine differentiation of the tumor (15) …show more content…
Regimens used in the ductal subtype can be used in the same way (21). Some studies showed an advantage in using anthracycline based chemotherapy in NEBC (22), whereas others didn’t show this benefit (2) (14). Some reports recommended the use of anthracycline based chemotherapy according to Ki-67 expression, usually if ki-67 is around 10%. For poorly differentiated carcinomas, especially the small cell subtype where ki-67 is more than 15% , cisplatin / etoposide is recommended as used in small cell pulmonary tumors (23) (24). Our case had a very high Ki-67 reaching 50%, and was treated with both cisplatin- and anthracycline-based
Many reports have addressed the prognosis of NEBC with conflicting observations, where some observed that it may be less aggressive than the usual invasive ductal carcinoma subtype (IDC) (1) (13), and others concluded that invasive neuroendocrine carcinoma of the breast has a poorer prognosis (14) than IDC. High nuclear grade, large tumor size, and regional lymph node metastasis were significant negative prognostic factors for distant recurrence-free survival (14). Others reported that NEBC has the same prognosis as other invasive breast cancers and is dependent on the staging, grading, mucin production and apocrine differentiation of the tumor (15) …show more content…
Regimens used in the ductal subtype can be used in the same way (21). Some studies showed an advantage in using anthracycline based chemotherapy in NEBC (22), whereas others didn’t show this benefit (2) (14). Some reports recommended the use of anthracycline based chemotherapy according to Ki-67 expression, usually if ki-67 is around 10%. For poorly differentiated carcinomas, especially the small cell subtype where ki-67 is more than 15% , cisplatin / etoposide is recommended as used in small cell pulmonary tumors (23) (24). Our case had a very high Ki-67 reaching 50%, and was treated with both cisplatin- and anthracycline-based