If you got skin cancer on your boobs would it still be skin cancer or would it be breast cancer?

The pathologist can tell them apart on a biopsy. Breast cancers are usually adenocarcinomas. Skin cancers are never adenocarcinomas. Skin cancers are basal call, squamous cell, or melanomas. A microscopic examination of biopsy tissue allows a pathologist to differentiate the types.

Skin cancer is skin cancer, the location of the skin is irrelevant. Breast cancer does not normally affect the skin but is inside the tissue.

It would be skin cancer. Breast cancer is in the actual breast tissue, not the skin of the breast.

The type of cancer is determined by the kind of cells they mutated from. Cancerous skin cells will always be skin cancer, no matter where they are located.

It would be skin cancer on your boobs and you'd be treated for skin cancer.

You answered your own question but if it spreads then is could be breast and skin cancer.

Skin is skin, breast tissue is breast tissue. And if other cancers spread, they're still whatever cancer they were. Doctors can recognize the various cells, and how they manifest in cancerous form still remains clear.

It would be skin cancer. Skin cancers are melanomas, sarcomas, etc. Each type of cancer has a specific morphology.