Neurotropic melanoma invading the median nerve

Area of Science:

• Oncology
• Neuropathology

Background:

• Acral lentiginous melanoma (ALM) is a rare subtype of cutaneous melanoma.
• It typically occurs on the palms, soles, or nail beds.

Observation:

• A case of ALM on the right thumbnail bed with intraneural invasion along the median nerve is presented.
• Recurrence occurred on the thenar eminence four years post-amputation, involving the median nerve and causing paralysis.

Findings:

• Histopathology revealed spindle-shaped cells forming neuroid fascicles, particularly in metastatic sites.
• Tumor cells tested positive for S-100 protein via immunohistochemistry.

Implications:

• This case underscores the aggressive nature of ALM with neural invasion.
• It emphasizes the challenges in managing advanced melanoma with perineural spread.