S-100

S-100 staining in a MASC.

S-100, also S100, is a commonly used immunostain. It marks nerves.

Positive

• Nerves.
• Mature adipose tissue.
• Interdigitating dendritic cells.
• Langerhans cell histiocytosis.
• Rosai-Dorfman disease.
• Schwannoma.

Malignant tumours

• Malignant melanoma - almost 100% sensitive.
• Malignant peripheral nerve sheath tumour.
• Clear cell sarcoma.

See also

• Immunohistochemistry.