Details
Soft tissue lesion from right ring finger.
Glomus tumours are benign tumours derived from the modified smooth muscle cells of the thermoregulatory glomus body, and represent approximately 2% of soft tissue tumors. Typically they are found as painful subungual lesions, however may be found in a wide variety of sites in the body.
Glomus tumours are composed of branching vascular channels and nests of small polygonal cells arranged around the vessels with regular spacing or a "cookie cutter" appearance. The cells have identifiable cellular borders and indistinct nucleoli. Glomus cells stain positive for smooth muscle actin, and usually do not stain for S100 or cytokeratins (Gombos Z et al., 2008). Malignant glomus tumours are rare, but have been reported to occur (Folpe AL et al, 2001).
See related content for references:
1) Folpe, AL., et al. Am J Surg Pathol. 2001 Jan;25(1):1-12.
2) Gombos, Z., Zhang PJ. Arch Pathol Lab Med. 2008 Sep;132(9):1448-52.