Not true about Medullary breast CA: –
**Medullary Breast Cancer Core Concept**
Medullary breast cancer is a rare subtype of invasive ductal carcinoma characterized by a unique histological appearance, often associated with a favorable prognosis due to its distinct immunophenotypic features and genetic alterations. This subtype accounts for approximately 3-5% of all breast cancers and is typically ER/PR negative and HER2 positive.
**Why the Correct Answer is Right**
Medullary breast cancer is often associated with a high frequency of BRCA1 mutations, which lead to the activation of the PI3K/AKT pathway, promoting cell survival and proliferation. The tumor microenvironment of medullary breast cancer is characterized by an abundance of tumor-infiltrating lymphocytes, which contribute to its favorable prognosis. The presence of a syncytial growth pattern, often accompanied by a lymphocytic infiltrate, is a hallmark of medullary breast cancer.
**Why Each Wrong Option is Incorrect**
**Option A:** While medullary breast cancer is often associated with BRCA1 mutations, it is not exclusively linked to these genetic alterations.
**Option B:** The prognosis of medullary breast cancer is generally favorable, but not universally so, and is highly dependent on the tumor's histological characteristics and the patient's overall health.
**Option C:** Medullary breast cancer is typically ER/PR negative, but this does not preclude the possibility of hormone receptor expression in some cases.
**Clinical Pearl / High-Yield Fact**
Medullary breast cancer often presents with a rapid growth rate and a high frequency of lymph node metastasis, which can lead to a worse prognosis if not adequately managed.
**Correct Answer: A. While medullary breast cancer is often associated with BRCA1 mutations, it is not exclusively linked to these genetic alterations.**