Jimmy Buffett continued to perform after being diagnosed with rare form of skin cancer

TAMPA, Fla. - Jimmy Buffett's cause of death was confirmed through his online obituary.

According to the front page of the singer's website, Buffett had battled Merkel Cell Carcinoma, a rare and aggressive form of skin cancer, for four years. 

Doctors say Merkel Cell Carcinoma, or MCC is about 40 times rarer than Melanoma, and effects about 3,000 people in the United States every year. According to the Mayo-Clinic, MCC tends to grow and spread quickly to other parts of the body.

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The singer-songwriter and entrepreneur continued to perform after being diagnosed, even making a surprise appearance on stage in Rhode Island in July. 

Jimmy Buffett was 76-year-old when he died.

Fans loved Buffett for his Beach Bum lifestyle, but here in Florida doctors say the sunshine puts residents at a higher risk of developing the rare and aggressive form of skin cancer.

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Patients that typically develop MCC have extended exposure to the sun, a weaker immune system, a history of other cancers, and are typically over the age of 50.

Jimmy Buffett was 76-year-old.

For more information in Merkel Cell Carcinoma, click here.