Lymphoma of the skin is a lymphocyte cancer that starts in the skin. Lymphocytes are immune cells that help kill bacteria, viruses and fungi. These cells are normally found in the lymph nodes, lymph tissues and other parts of the body, including the skin, explains the American Cancer Society.
Lymphomas that spread to the skin from other sites of the body are not skin lymphomas. All skin lymphomas are non-Hodgkin lymphomas and have either a T-cell or B-cell origin, although T-cell skin lymphomas are the most common, explains the American Cancer Society.
Almost half of all skin lymphomas are mycosis fungoides. This is a slowly growing cancer that initially presents as a patchy, scaly skin lesion, making it difficult to diagnose. It can eventually develop into a solid, raised tumor and spread to other organs, such as the liver, according to the American Cancer Society.
Other T-cell skin lymphomas include Sezary syndrome, which can develop in patients with mycosis fungoides, primary cutaneous anaplastic large cell lymphoma, lymphomatoid papulosis, subcutaneous panniculitis-like T-cell lymphoma, and a group of less common lymphomas, explains the American Cancer Society.
The most common B-cell skin lymphoma is primary cutaneous follicle-center lymphoma. This cancer grows slowly and looks like a group of red pimples, plaques or nodules, which most frequently appear on the scalp, shoulders and torso, according to the American Cancer Society.