POSTTRAUMATIC SUBUNGUAL ACRAL NODULAR MELANOMA WITH BONE INFILTRATION TREATED VIA AMPUTATION OF THE DISTAL AND MIDDLE PHALANX: DESCRIPTION OF A CASE AND UPDATE ON THE TOPIC.

Abstract

Acral lentiginous melanoma (ALM) is a rare type of cutaneous malignant melanoma, predominantly affecting the acral sites and subungual regions of the upper and lower extremities. Unlike other melanoma types, UV exposure is not considered as significant etiological factor. Instead, mechanical stress, particularly traumatic injury, is recognized as a potential contributor to ALM development, especially in weight-bearing areas such as the sole. The presence of pre-existing pigmented lesions may serve as precursors. While diagnostic and therapeutic approaches for skin cancer are well-established in existing guidelines - such as those proposed by the European Joint Committee (EJC) and the American Joint Committee on Cancer (AJCC) - certain limitations are evident. These standardized protocols may not be fully beneficial for each patient, which highlights the need for a more personalized, patient-focused approach. In response, alternative methodologies, including the personalized One Step Melanoma Surgery (OSMS), have been introduced. OSMS offers a single-stage surgical intervention that minimizes both financial and psychological burdens compared to the conventional two-step approach protocol by the EJC and AJCC guidelines. We present a 57-year-old woman with a tumor-like lesion on the right hallux. A prior injury 30-years earlier was reported, after which a pigmented lesion developed and remains stable for decades. Following a recent domestic trauma, the lesion underwent rapid malignant transformation into an aggressive subungual acral nodular melanoma with subsequent bone infiltration, staged IIC T4bN0M0, Clark level IIC, Breslow thickness >4mm. Amputation of the right distal and proximal phalanx of digitus I (hallux) was performed. BRAF testing, re-excision with a 1.7 cm margin with a sentinel lymph node biopsy within 2-4 weeks, and initiation of immunotherapy or targeted therapy, were recommended.