Melanoma

Also known as MART-1, for Melanocytic Antigen Recognized by cytotoxic T lymphocytes from melanoma patients, it is a sensitive and specific cytoplasmic protein for melanoma.

The tumor is highly cellular and consists of plump spindled cells arrayed in broad fascicles and oriented perpendicularly to blood vessels.

The brain tissue surrounding this metastatic tumor mass has acute neuronal necrosis.

S-100is structurally similar to calmodulin and gets its name from the fact that it is 100% soluble in ammonium sulfate at neutral pH.