Neuroendocrine Carcinoma of the Breast, NOS
Definition
- Breast carcinoma expressing predominant neuroendocrine differentiation but lacking specific cyto-architectural features of low grade or high grade neuroendocrine carcinoma
Diagnostic Criteria
- At least 50% of cells are neuroendocrine marker positive
- We require either synaptophysin or chromogranin
- We do not consider neuron specific enolase to be sufficiently specific for this diagnosis
- Any conventional breast carcinoma pattern excluding those of:
- Low grade neuroendocrine carcinoma
- Solid sheets, insular pattern or large round masses
- Stippled chromatin
- Low grade cytologic features
- High grade neuroendocrine carcinoma
- Small cell carcinoma
- Low grade neuroendocrine carcinoma
- Small numbers reported but there is no clear clinical difference from conventional carcinoma
Richard L Kempson MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting:: November 15, 2006