S100 protein expression in scattered dendritic cells in a high grade sarcoma. Such staining should not be interpreted as positive staining of tumor cells.
S100 protein expression in adipocytes.
S100 protein staining in sustentacular cells surrounding nests of paraganglioma cells. Note the paraganglioma cells are negative.
S100 protein staining in sustentacular cells surrounding nests of paraganglioma cells. Note the paraganglioma cells are negative.
S100 protein staining in sustentacular cells surrounding nests of paraganglioma cells. Note the paraganglioma cells are negative.
S100 protein staining in sustentacular cells surrounding nests of paraganglioma cells. Note the paraganglioma cells are negative.
Focal, patchy S100 protein expression in malginant peripheral nerve sheath tumor (MPNST).
Focal, patchy S100 protein expression in malginant peripheral nerve sheath tumor (MPNST).
Focal, patchy S100 protein expression in malginant peripheral nerve sheath tumor (MPNST).
S100 protein expression in a schwannoma. Note the hyalinized vessels.
S100 protein staining myoepithelial cells in the parotid gland.
S100 protein expression in myoepithelioma (parachordoma) of soft tissue.
S100 protein expression in myoepithelioma (parachordoma) of soft tissue.
S100 protein expression in myoepithelioma (parachordoma) of soft tissue.
S100 protein expression in myoepithelioma (parachordoma) of soft tissue.
S100 protein highlighting histiocytes with emperipolesis in Rosai-Dorfman Disease.
S100 protein highlighting histiocytes with emperipolesis in Rosai-Dorfman Disease.
S100 protein highlighting histiocytes with emperipolesis in Rosai-Dorfman Disease.
S100 protein highlighting histiocytes with emperipolesis in Rosai-Dorfman Disease.
S100 protein highlighting histiocytes with emperipolesis in Rosai-Dorfman Disease.
S100 protein highlighting histiocytes with emperipolesis in Rosai-Dorfman Disease.
S100 protein highlighting histiocytes with emperipolesis in Rosai-Dorfman Disease.
S100 expression in dendritic Langerhans cells (mid-epidermis) and melanocytes (basal) in the skin.
S100 expression in neurotropic desmoplastic melanoma.
S100 expression in neurotropic desmoplastic melanoma.
S100 expression in neurotropic desmoplastic melanoma.
S100 expression in neurotropic desmoplastic melanoma.
S100 expression in neurotropic desmoplastic melanoma.
S100 expression in neurotropic desmoplastic melanoma.
S100 expression in neurotropic desmoplastic melanoma.
S100 expression in neurotropic desmoplastic melanoma.
S100 expression in neurotropic desmoplastic melanoma.
This antigen is typically negative in the following:
Malignant peripheral nerve sheath tumor (MPNST). This is a common misunderstanding among pathologists. Approximately 50% of MPNST are totally negative for S100 protein. Those that are positive usually have only weak, focal, patchy staining. One exception is epithelioid MPNST, a tumor which is typically strongly S100 protein positive.
Only focally positive in meningioma with stronger cytoplasmic staining than nuclear staining (schwannoma is strongly and diffusely positive with nuclear staining predominating)[1]