Diagnosis and Management of Post-Mastectomy Fat Necrosis

Initial Diagnostic Approach

Ultrasound is the initial imaging modality of choice for evaluating any palpable mass in the post-mastectomy setting without reconstruction, as recommended by the American College of Radiology 1, 2
Diagnostic mammography or digital breast tomosynthesis (DBT) can be used as a complementary tool when ultrasound findings are indeterminate or suggestive of fat necrosis, to identify characteristic benign features such as oil cysts and avoid unnecessary biopsy, according to the American College of Radiology 3, 4

Fat necrosis is a common sequela in the post-mastectomy setting, occurring most commonly in the early postoperative period but can present as a delayed complication, as noted by the American College of Radiology 5
Awareness of fat necrosis is critical to avoid unnecessary mastectomy or aggressive surgical procedures when conservative diagnostic approaches can establish the diagnosis, and never assume a palpable mass is benign fat necrosis without tissue diagnosis, as recurrence rates after mastectomy can present as palpable lumps, as cautioned by the American College of Radiology 5