Persistent wound

A 38-year-old custom shop owner came to the clinic complaining of a skin lesion that bothered him at work. It is constant and has been slowly growing over the past six months and occasionally discharges a small amount of pus. It is associated with dull pain 2/10 which does not radiate. No significant past medical, taking no medications, and undergoing any treatment. His job is to build and maintain custom aquariums, and he denied any recent trauma. His vital signs are normal. His physical examination revealed a well-defined, raised erythematous nodule, approximately 2 cm in diameter, on the dorsal aspect of his right hand, and exhibited a central ulceration as shown in the image. The nodule is firm with mild tenderness upon palpation, no fluctuance or regional lymphadenopathy is detected. The remainder of the skin examination is unremarkable. Waiting on a skin biopsy and culture result. Which of the following diagnoses is most likely,