Complex Reconstruction of a Pelvic Marjolin's Ulcer Arising from Hidradenitis Suppurativa.

The chronic inflammation of hidradenitis suppurativa can cause painful nodules, draining abscesses, sinus tracts, and fibrous scars. This long-term cutaneous inflammation in rare circumstances can lead to malignant transformation producing an aggressive cutaneous malignancy referred to as a Marjolin's ulcer. Particularly when a Marjolin's ulcer involves the sacral region, resection and reconstruction can be challenging. We present the case of a patient with a recurrent Marjolin's ulcer originating from a hidradenitis wound bed overlying and involving the sacrum. Previous radiation, large defect size, and sacral and perianal involvement necessitated the use of a multiflap approach. An extended transpelvic vertical rectus abdominis myocutaneous flap, bilateral gluteal advancement flaps, and a delayed transverse back flap were used to reconstruct the defect after abdominoperineal resection and nerve-sparing partial sacrectomy. Flap choice was derived by dividing the defect into anatomic subunits and considering intrapelvic defect volume, creating a systematic approach that led to successful reconstruction and functional restoration.