Final answer:
The primary care provider is involved in referring the patient to an oncologist after the diagnosis of malignant melanoma.
Step-by-step explanation:
When a patient has been diagnosed with malignant melanoma, the process in which the primary care provider is taking part by transitioning patient care to an oncologist is referring the patient to an oncologist. Dermatologists, who often work in medical office or private-practice settings, are typically tasked with the initial diagnosis of skin conditions, and upon diagnosing a condition such as malignant melanoma, they would then make a referral to an oncologist for specialized treatment. The referred oncologist will then oversee the treatment planning and management, which may include surgical excision and immunotherapy, among other modalities.