Chronic expanding hematoma involving the pectoralis major muscle years after breast implant removal: a case report

Late hematoma is a rare complication of implant-based breast augmentation and has seldom been reported after implant removal. We describe a 36-year-old woman with a hard, fixed, painless mass at the left inframammary fold that had slowly enlarged over 3 years. She had undergone bilateral augmentation mammoplasty 10 years earlier and implant removal 7 years earlier. Magnetic resonance imaging showed a 9-cm lobulated, rim-enhancing lesion comprising a 7-cm retropectoral cystic component connected to a 3-cm septated component in the lower lateral chest wall. The lesion showed early rapid enhancement with delayed washout on kinetic analysis but a persistent pattern on reverse subtraction images. Ultrasonography suggested a granuloma associated with retained implant material. Exploration through an inframammary fold incision revealed dark red old blood and clots without a solid tumor component, and the hematoma was evacuated. Recovery was uneventful, with no complications reported during 2 months of follow-up. Chronic expanding hematoma should be considered when evaluating a slowly growing mass in a former implant pocket, even years after explantation, because its imaging features may mimic retained silicone, implant-associated lymphoma, or soft tissue sarcoma.