Synergism of Therapies After Postoperative Autograft Failure in a Patient With Melanoma of the Foot Misdiagnosed as a Pressure Ulcer

Introduction. Amelanotic melanoma of the foot is a diagnostic challenge for physicians as it often appears as a benign lesion. In order to make the correct diagnosis at early stages, it is recommended to perform a biopsy of worsening lesions that are refractory to standard treatments, particularly nonhealing wounds. Case Report. The authors describe the case of a 57-year-old man with amelanotic melanoma of the foot that had been treated as a pressure ulcer for 3 months. He underwent wide local excision of the melanoma and an application of skin autograft. After skin autograft failure, optimal wound bed preparation was achieved through negative pressure wound therapy and compression bandages associated with hyperbaric therapy. Complete wound healing was obtained with an epidermal fractional skin grafting system combined with compressive inelastic bandages. Conclusions. Physicians must remain highly cautious of ulcerated lesions of the foot and may consider epidermal fractional skin grafting as a valid therapeutic option in case of postsurgical wounds resulting from wide local excision of malignant melanomas.

Amelanotic melanoma of the foot is frequently misdiagnosed as a wart, vascular lesion, or pressure ulcer, which leads to poor prognosis. Melanoma on the foot requires wide local excision and correct postoperative wound care.

The case of a 57-year-old man with an amelanotic melanoma of the foot misdiagnosed as a pressure ulcer, treated with standard and new therapies after postoperative autograft failure is presented.

A 57-year-old Caucasian man presented  to the Wound Healing Research Unit at the University of Pisa (Pisa, Italy) with an ulcer over the fifth metatarsal of his right foot that had been treated as a pressure ulcer for 3 months. The patient reported a metatarsal fracture of the right foot with a subsequent plaster cast application 1 month prior to observation of the ulcerated lesion, noted after cast removal (Figure 1A). 

A skin biopsy of the lesion was performed and histological examination revealed the presence of a nodular melanoma with 9-mm Breslow thickness, ulceration, regression, 6 mitoses/mm², and vascular invasion. Clinical examination showed an enlarged lymph node in the right groin area, and the computed tomography imaging revealed 3 suspected metastatic lymph nodes, which were excised and analyzed. No organ metastases were found and the tumor stage was IIIC.

The patient underwent a wide toe-sparing excision of the primary tumor followed by skin autograft at another hospital; excision of the metastatic lymph nodes also was performed. One month after the autograft application,  the patient developed autograft failure (Figure 1B). He was unable to perform  routine activities due to pain and the odor of wound drainage. Lesion surface area was 37.21 cm² with no clinical signs of infection. He was treated with hydrofiber with silver (AQUACEL Ag; ConvaTec, Leeside, Flintshire, UK) and compressive inelastic bandages (Co-Plus; BSN medical, Hamburg, Germany). After 1 week of this treatment (2 dressing changes), negative pressure wound therapy (NPWT) with a portable device (V.A.C.VIA; Acelity, San Antonio, TX) was applied with continuous pressure at -125 mm Hg.

The portable NPWT was changed weekly, in consideration of wound size and exudation; compressive inelastic bandages were added in combination for 2 weeks. During the entire treatment duration (3 weeks), the patient also received localized hyperbaric therapy once daily for 2 hours. 

After 2 weeks of NPWT combined with compression bandages, the wound area improved in terms of size (8.7 cm²) and granulation tissue development, but the lesion remained very painful (Figure 1C). The authors opted for a, noninvasive technique to resurface the wound with epidermal fractional grafts. The grafts were obtained with an epidermal fractional skin grafting system (CELLUTOME; Acelity) that combines vacuum and heat and yields thin sections with constant orientation of epidermal skin from the dermoepidermal junction. Saline was used for donor area (inner thigh) cleansing, and the vacuum head and the harvester were applied. Microdomes formed under visual observation by about 30 minutes. A nonadherent silicone dressing (ADAPTIC TOUCH; Acelity) was used to transfer the microdomes to the recipient site and to cover the donor area. A compressive inelastic bandage was applied on the recipient site. First follow-up was scheduled within 3 days after the bandage was applied and then weekly for the following 3 weeks. Complete healing of the donor site was achieved after 14 days and of the treated area after 21 days (Figure 1D).

Nodular melanoma represents about 15% of melanomas and is characterized by rapid progression with vertical growth from the beginning.¹ Melanomas originating on the foot are often misdiagnosed as benign lesions (such as pyogenic granulomas), warts, or traumatic lesions and show a worse prognosis than melanomas elsewhere on the body.² The partial or total lack of pigment on visual inspection in amelanotic melanomas can further conceal the nature of the lesion, and the typical high Breslow thickness at the time of diagnosis is associated with poorer prognosis.³ 

Skin biopsy is strongly recommended in cases of nonhealing wounds, refractory to standard treatments, in order to make a correct early diagnosis.⁴ Melanoma of the foot needs wide local excision, and postsurgical wound care may require the use of skin grafts. Close monitoring is needed in order to detect early potential melanoma recurrences.

In this complex case, good wound bed preparation was obtained by using NPWT and compression bandages on the postsurgical autograft failure. Epidermal skin grafting was later performed using a noninvasive technique. Indications for the use of this technique are acute wounds, burns, and various types of small dimension, mildly exudating, and well-granulating chronic ulcers.⁵ Moreover, the technique has been described as a safe and effective treatment in patients with stable vitiligo unresponsive to standard therapies.^5,6

This device provides a new precise and reproducible technique to achieve the complete healing of different wounds with minimal traumatism and satisfactory aesthetic results.⁷ The risk of complications at the donor or recipient site is low and donor site pain is minimal.^8-10 Further studies are needed  to confirm the effectiveness of this device for treating complex nonhealing wounds.

Clinicians must remain highly cautious when evaluating ulcerated  lesions on the foot and may consider epidermal fractional skin grafting combined with standard wound  healing treatment as a good option in the case of postsurgical wounds due to the wide local excision required for malignant melanoma. 

Affiliation: Wound Healing Research Unit, Department of Dermatology, University of Pisa, Pisa, Italy

Correspondence: Agata Janowska, MD, Department of Dermatology, University of Pisa, Via Roma 67, 56124, Pisa, Italy; dottoressajanowska@gmail.com

Disclosure: The authors disclose no financial or other conflicts of interest.