👉 Thyroid peritoneal lymphoma is a type of cancer that affects the lining of the thyroid gland, which is an organ in the neck. It's a rare form of cancer and it can grow anywhere in the body. Thyroid peritoneal lymphomas are very serious because they cause pain or swelling under your skin, like when you rub your thumb on a hot stove. It's usually not treatable, but some people do get better with treatment. If you have thyroid peritone
