Bilateral inflammatory breast cancer treated with pembrolizumab and surgery

What happened, in summary

This 49-year-old woman presented after several weeks of redness and warmth in both breasts. Examination showed redness and skin thickening bilaterally. Biopsies confirmed invasive ductal carcinoma in both breasts, but the biology differed by side. The right breast had luminal invasive ductal carcinoma, grade 1, with ER >90%, PR >90%, HER2 2+ but FISH-negative status, and Ki-67 of 10%. The left breast had triple-negative invasive ductal carcinoma, grade 3, with ER 0%, PR 0%, HER2 1+, and Ki-67 of 21%. Skin infiltration was present on both sides. MRI showed skin thickening and multiple enhancing nodules throughout the breasts. PET-CT showed axillary lymph node involvement but no distant metastasis, and the disease was staged cT4dN3cM0, Stage IIIC bilateral inflammatory breast cancer. She received pembrolizumab-based neoadjuvant chemotherapy. Redness improved, but skin thickening and MRI enhancement persisted. Surgery required bilateral mastectomy with removal of all thickened skin and bilateral axillary lymph node dissection. The resulting skin defects were large, 17 × 15 cm on each side, and could not be closed primarily. Because she did not want immediate or delayed breast reconstruction, surgeons closed the wounds with bilateral thoracoabdominal flaps and used indocyanine green imaging to remove poorly perfused tissue. Margins were negative, though carcinoma was close to the resection margins. She healed well, with all drains removed by postoperative day 9, and she was discharged with good wound healing. The flap color and texture matched well during follow-up, and she had no restriction in upper-limb range of motion, although mild abdominal scar hypertrophy was noted. Postmastectomy radiation was delayed because of immune-related adverse events. As of March 2025, 6 months after surgery, no recurrence was observed.