Jane is a thirty-three-year-old concerned about the possibility of breast disease. A maternal aunt was diagnosed with invasive breast cancer at the age of forty-eight. Jane’s mother (age sixty-two) has been biopsied on several occasions for suspicious breast lesions that were diagnosed as benign cysts, and twice as a fibroadenomas. Because of her concern, Jane is careful to practice breast self-examination and has elected to have yearly mammography starting at age thirty. Jane paid to be tested for BRCA1 and BRCA2 and was found to be negative. She has been diagnosed as having mild fibrocystic disease but otherwise had a normal mammogram six months ago. On self-examination, Jane now notes a single hard mass in the upper inner quadrant of her left breast. The mass appeared to be adherent to the skin. Jane’s physician confirmed a 3 cm mass that was tender to firm palpation. The physician noted a slight skin retraction over the mass and was concerned about the possibility of a rapidly growing carcinoma. Mammography revealed an irregular mass with some architectural distortion and calcification, supporting the concern for malignancy. Because of this concern, Jane elected to have an excisional biopsy in which the entire mass was removed. The surgeon noted the mass was yellow in color, appeared to be fibrotic with areas of calcification, and had several small cystic regions. Microscopic analysis of the tissue (FIGURE 16-13) demonstrates a process consistent with fat necrosis of the breast. This is a specific form of necrosis associated with damage to areas of the body rich in lipid-containing cells. Fat necrosis in the breast is a benign process that requires no therapy. However, the process may be difficult to differentiate from cancer and requires biopsy for diagnosis. A much relieved Jane is carefully questioned about possible trauma to her breast. About three months before noting the mass, Jane remembers that she came to a very sudden stop while driving. She noted some bruising and pain along the area of her breast crossed by the seatbelt.
FIGURE 16-13
Discussion
Fat necrosis (also termed enzymatic fat necrosis) is a sterile form of inflammation that occurs after trauma (or other damage) to areas of the body rich in lipid. In fat necrosis, lipid released from damaged fat cells is saponified (converted to soap) by tissue lipases in the presence of calcium. The lipid may form cysts in the tissue and provokes a chronic inflammatory response. Macrophages ingest the lipid (foamy macrophages) and fuse to form giant cells in response to the irritant material. Ultimately, healing occurs accompanied by fibrosis (scarring), deposition of calcium in the tissue, and potentially residual lipid cysts. Pathologists usually think about the area around the pancreas when they consider fat necrosis because it is common in this region in response to pancreatitis. (In this setting fat necrosis has serious medical consequences.) However, fat necrosis is not uncommon in the breast and buttocks. Fat necrosis accounts for about 3 percent of benign breast lesions. Seatbelt induced injury and trauma related to breast surgery are common causes. Most cases of fat necrosis in the breast are easy to diagnosis based on the presence of radiolucent cysts (using mammography often combined with ultrasound) and may not require biopsy. With time, continuing inflammation, fibrosis, and calcification may present in a manner similar to cancer and require biopsy. For this reason, a careful patient history that discloses possible breast trauma is important in the clinical decision-making process. Although it was understandable for Jane to be concerned about breast cancer given her history, it is important to realize that the majority of breast lesions biopsied are not cancer (FIGURE 16-14).
FIGURE 16-14
Questions
1. Given Jane’s family history, were her concerns about early onset breast cancer justified?
2. The American Cancer Society suggests routine mammography begin at age forty. Other expert opinions suggest starting later. What drawbacks would there be to recommending routine mammography very early (at age twenty or thirty, for example)?
3. Suppose Jane’s mammogram disclosed a cystic area. Do you believe she would have been wise to proceed to a biopsy?