Treatment

The lesion was completely excised under local anesthesia.

Excisional Biopsy

Histologic examination reveals a hemisected piece of soft tissue composed of thin and keratinized surface epithelium with underlying fibrous connective tissue almost all occupied by loose and vascular granulation tissue (Figure 2). The granulation tissue contains sheets of large "histiocytes" interspersed with multinucleated giant cells and significant aggregates of eosinophils (Figure 3). The granulation tissue is also infiltrated by many plasma cells, lymphocytes and neutrophils. Using Immunohistochemistry staining, the "histiocytes" were uniformly positive with antibody to CD1a (Figure 4).

Figure 2 Low power (x40) H & E stained histology shows a mass of vascular granulation tissue containing sheets of large "histiocytes" interspersed with multinucleated giant cells and significant aggregates of eosinophils.

Figure 3 Higher power (x200) H & E stained histology shows a mass of vascular granulation tissue containing sheets of large "histiocytes" interspersed with multinucleated giant cells and significant aggregates of eosinophils.

Figure 4 High power (x200) Immunohistochemistry stain with antibody to CD1a, the "histiocytes" were uniformly positive with this antibody.