Question: What is a sarcomatoid carcinoma? My core biopsy report said “invasive carcinoma with spindle cell features, cannot rule out sarcomatoid carcinoma.”

Answer: Sarcomatoid carcinoma is a type of metaplastic carcinoma. These are invasive carcinomas of the breast but they just look different under the microscope than the usual type of invasive carcinoma, NST. The pathologist still needs to run the prognostic marker panel on your tumor (ER/PR/HER2) and you should still have your lymph nodes evaluated to make sure the cancer has not spread there.