Morphologic spectrum, immunohistochemical analysis, and clinical features of a series of granular cell tumors of soft tissues: a study from a tertiary referral cancer center

Ann Diagn Pathol. 2010 Jun;14(3):162-7. doi: 10.1016/j.anndiagpath.2010.01.005.

Abstract

A granular cell tumor (GCT) is relatively uncommon and objectively diagnosed with neural markers on immunohistochemistry (IHC). Recent studies have described additional markers for a GCT. Herein, we present morphologic spectrum of 12 GCTs of soft tissues and skin, including 10 benign and 2 malignant subtypes with an optimal diagnostic IHC panel. Eleven cases occurred in women and 1 in a man, with a mean age of 45.5 years. Six cases occurred in soft tissues and skin of extremities, 4 in the breast soft tissues, and 1 case each in the back and preauricular region, respectively. Cytologic smears in 2 cases displayed polygonal cells with abundant, eosinophilic, granular cytoplasm. On histopathology, all cases invariably revealed a nonencapsulated infiltrating tumor comprising groups and nests of granular cells with vesicular nuclei. In 5 cases, granular cells were noted in close proximity to the nerves. Two malignant GCTs revealed necrosis, mitoses, and nuclear atypia. Immunohistochemistry in 10 cases (83.3%) showed diffuse S-100 positivity in all 7 benign and 2 malignant cases: cytoplasmic CD68 positivity (all 10 cases) and membranous vimentin staining (all 4 cases). Inhibin showed cytoplasmic positivity in 3 of 6 cases. A single malignant GCT showed focal desmin reactivity. All were surgically managed. A GCT is a discrete tumor entity and can be identified from other granular lesions by its proximity to nerves and objective identification with diffuse S-100 positivity, CD68 positivity, and membranous vimentin positivity that form an optimal IHC panel in limited resource settings, irrespective of benign or malignant types.

MeSH terms

  • Adult
  • Aged
  • Antigens, CD / metabolism
  • Antigens, Differentiation, Myelomonocytic / metabolism
  • Biomarkers, Tumor / metabolism
  • Cancer Care Facilities*
  • Child
  • Female
  • Granular Cell Tumor / metabolism
  • Granular Cell Tumor / pathology*
  • Granular Cell Tumor / surgery
  • Humans
  • Male
  • Middle Aged
  • Referral and Consultation*
  • S100 Proteins / metabolism
  • Skin Neoplasms / metabolism
  • Skin Neoplasms / pathology*
  • Skin Neoplasms / surgery
  • Soft Tissue Neoplasms / metabolism
  • Soft Tissue Neoplasms / pathology*
  • Soft Tissue Neoplasms / surgery
  • Vimentin / metabolism
  • Young Adult

Substances

  • Antigens, CD
  • Antigens, Differentiation, Myelomonocytic
  • Biomarkers, Tumor
  • CD68 antigen, human
  • S100 Proteins
  • Vimentin