From the Guidelines
Glomus Tumor Staining
No, Glomus tumors do not typically stain positive for S100, a protein marker. According to the provided evidence, S100 is usually expressed in melanoma, clear cell sarcoma, glioma, and malignant peripheral nerve sheath tumors 1.
Immunohistochemical Features
The characteristic immunohistochemical features of Glomus tumors include positivity for smooth muscle actin and vimentin, while being negative for CD117 (c-kit) staining, which helps to differentiate these lesions from GISTs 1.
Diagnostic Considerations
In the context of diagnosing Glomus tumors, it is essential to consider the clinical presentation, imaging findings, and immunohistochemical results. While S100 staining is not typically associated with Glomus tumors, other markers such as smooth muscle actin and vimentin can aid in the diagnosis 1.
Key Points
- Glomus tumors do not typically stain positive for S100.
- Characteristic immunohistochemical features of Glomus tumors include positivity for smooth muscle actin and vimentin.
- S100 staining is more commonly associated with melanoma, clear cell sarcoma, glioma, and malignant peripheral nerve sheath tumors.
From the Research
Glomus Tumor and S100 Staining
- The staining of Glomus tumors for S100 protein has been investigated in several studies, with varying results.
- A study from 2013 2 found that all samples of Glomus tumors were positive for S100 protein.
- However, other studies have found that Glomus tumors are negative for S100 staining, including a study from 2021 3 and a study from 1989 4.
- A study from 1985 5 found that S-100 protein immunoreactivity was present in nerve fascicles in the capsule of the tumor, and in a few cells scattered throughout the stroma of the tumor.
- Another study from 1994 6 found that no positive staining was seen with S100 in Glomus tumor cells.
- These conflicting results suggest that the staining of Glomus tumors for S100 protein may not be a reliable diagnostic marker.
Immunohistochemical Characteristics of Glomus Tumors
- Glomus tumors have been found to be positive for various immunohistochemical markers, including alpha-smooth muscle actin (α-SMA) and h-caldesmon 3.
- They are also positive for muscle-specific actin and vimentin 4.
- However, they are typically negative for markers such as cytokeratin, neurofilaments, and Factor VIII-related antigen 4, 6.
- The immunohistochemical profile of Glomus tumors may be useful in the differential diagnosis of atypical Glomus tumors.
Clinical and Histopathological Features of Glomus Tumors
- Glomus tumors are benign hamartomas that account for 1% to 5% of all soft-tissue tumors of the hand 2.
- They are typically characterized by a symptomatic triad of pain, temperature sensitivity, and tenderness 3.
- The diagnosis of Glomus tumors is made by pathological examination, often aided by immunohistochemical markers 3.