SOX10 vs S100 in IHC

The short answer

SOX10 and S100 are both useful when melanocytic or Schwannian differentiation is being considered. SOX10 is read as a nuclear stain; S100 can stain nuclei and cytoplasm. In melanoma cytology specimens, SOX10’s nuclear pattern can be easier to distinguish from pigmented or nonspecific background, but a positive result from either marker is not a diagnosis by itself.^[1][3]

What each stain contributes

SOX10 is a sensitive lineage marker in many melanocytic lesions and is also seen in Schwannian tumors. Its nuclear signal can help distinguish stained lesional cells from cytoplasmic pigment or some background cells. S100 has long been used as a sensitive marker in this setting, but it labels a wider range of non-melanocytic cells and lesions.^[1][2][3]

Sensitivity and specificity depend on the specimen and differential diagnosis. The literature does not support treating SOX10 positivity as melanoma-specific or using a single universal sensitivity ranking against S100.^[1][3]

In a review of melanoma cytology studies, both SOX10 and S100 performed as sensitive stains on cell-block material, while SOX10's nuclear signal was easier to distinguish from some pigmented background. That observation is specific to the studied material, not a promise that either stain will perform identically in every tissue or laboratory.^[3]

Interpretation limits

SOX10 can also be expressed in some non-melanocytic tumors, including subsets of breast and salivary gland carcinomas. S100 labels several normal and neoplastic cell types. Morphology, clinical context, controls, and other stains therefore remain part of interpretation.^[1][2]

Relevant ReagentScope records

The ReagentScope SOX10 marker page links to a verified Bio SB SOX10 EP268 product page. ReagentScope does not currently list an S100 product; this scientific comparison should not be read as a product comparison.^[4]