Melanoma recurrence confined to a free flap after isolated limb perfusion

We present the case of a 72-year-old female presenting to our unit with locally recurrent malignant melanoma of the lower limb almost entirely confined to a fasciocutaneous free flap. The flap (lateral arm donor site) had been used several years previously to reconstruct a wide local excision defect following the excision of recurrent disease. The striking difference about this case is that the recurrence observed after isolated limb perfusion (ILP) was almost entirely confined to the flap rather than the affected limb. Several possible explanations for this phenomenon are discussed--considering factors such as altered flap lymphatics, neuronal factors, and differential flap-versus-normal tissue response to the tumour necrosis factor used in ILP. The case highlights interesting questions about the mechanism of action of ILP--especially with regard to free flap tissue--and unknowns regarding tumour spread across wound scar boundaries.