What is the appropriate step in the management of a suspected malignant melanoma based on typical treatment guidelines?

The appropriate step in the management of a suspected malignant melanoma is local excision with biopsy. This procedure is crucial because it not only removes the suspicious lesion, allowing for accurate histopathological examination, but it also serves as the first line of treatment for melanoma. If melanoma is diagnosed, the extent of surgical excision can also be determined based on the biopsy results.

The local excision significantly contributes to the staging of the melanoma, helping to assess the depth of the tumor and whether there are any signs of metastasis. Evaluating these factors is essential for planning further treatment strategies, which may include more extensive surgery, immunotherapy, or targeted therapies if the cancer is invasive.

In contrast, topical chemotherapy, observation only, and cryotherapy are not adequate initial management strategies for suspected malignant melanoma. Topical chemotherapy is typically reserved for superficial lesions or non-melanoma skin cancers and does not effectively treat deeper or invasive melanomas. Observation alone does not address the need for immediate action in the presence of a potential malignancy, while cryotherapy is not a recommended treatment for melanoma, as it is best suited for superficial skin lesions that require destruction rather than excision.