A 75-year-old man presents with a lesion on his back that appeared suddenly and grew rapidly over a few weeks. The lesion is firm, irregular, and brownish-black. What could be the potential diagnosis and next steps?
The sudden appearance and rapid growth of the described lesion raise concern for nodular melanoma, a subtype of melanoma that can grow more quickly than other types. Given the concerning features of the lesion, a biopsy should be performed to confirm the diagnosis. If melanoma is confirmed, further work-up including sentinel lymph node biopsy and possible imaging studies would be required to stage the disease and guide treatment.