A Rare Complication Following Breast Conserving Surgery: Pyoderma Gangrenosum.

Pyoderma gangrenosum (PG) after breast-conserving surgery is rare, and its diagnosis is often delayed because of the similarity to wound infection and the broad differential diagnosis for PG, making it a diagnosis of exclusion. A 60-year-old woman who underwent breast conserving surgery and sentinel lymph node biopsy for invasive breast carcinoma presented with increasing erythema, fever and serosanguinous discharge in the lower outer quadrant of the right breast at the site of tumour excision on postoperative day (POD) 9. Fever persisted despite antibiotics and the patient was noted to have leucocytosis (0.9 x 10⁹/L), neutrophilia (37.8 x 10⁹/L) and elevated C-reactive protein levels (136 μg/mL) on POD 16. Microbiology and blood culture results were negative but the breast ulcer continued to expand at a rate of 1-2 cm a day. The patient underwent surgical debridement on POD 21 to rule out necrotising soft tissue infection. Persistent ulcer progression, despite debridement and antibiotics, led to clinical suspicion of PG and the patient was started on prednisolone and cyclosporin. A rapid response was seen with treatment and an optimum healing process was noted over the subsequent three-month follow-up period. Early suspicion, careful macroscopic evaluation of disease progression and appropriate use of immunosuppressive therapy are important for the management of PG. Prompt initiation of immunosuppressive therapy may avoid unnecessary treatment and aggravation of the surgical wound.