A 55-year-old man with a 30-year history of occupational arsenic exposure presents with multiple hyperkeratotic papules on the palms and soles, along with a 2 cm indurated nodule on the dorsum of the right hand with irregular borders and central ulceration. Dermoscopy shows a vascular pattern with arborizing vessels. Histopathology reveals infiltrative nests of atypical keratinocytes with perineural invasion. Which of the following is the most likely diagnosis?