Pleomorphic fibroma and dermal atypical lipomatous tumor: are they related?

Authors

  • Tariq Al-Zaid,

    Corresponding author
    • Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
    Search for more papers by this author
    • Present address: Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia

  • Wei-Lien Wang,

    1. Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
    Search for more papers by this author
  • Dolores Lopez-Terrada,

    1. Department of Pathology, Texas Children Hospital, Houston, TX, USA
    Search for more papers by this author
  • Dina Lev,

    1. Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
    2. Sarcoma Research Center, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
    Search for more papers by this author
  • Jason L. Hornick,

    1. Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
    Search for more papers by this author
  • A. Hafeez Diwan,

    1. Department of Pathology, Baylor College of Medicine, Houston, TX, USA
    Search for more papers by this author
  • Christopher D. M. Fletcher,

    1. Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
    Search for more papers by this author
  • Alexander J. Lazar

    1. Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
    2. Sarcoma Research Center, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
    3. Department of Dermatology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
    Search for more papers by this author

Tariq Al-Zaid, MD,

The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Unit 0085, Houston, Texas 77030-4009, USA

Tel: 713-743-1843

Fax: 713-745-0789

e-mail: talzaid2010@gmail.com

Abstract

Pleomorphic fibromas represent dome-shaped or polypoid cutaneous lesions characterized by a paucicellular and densely fibrotic background punctuated by scattered atypical to pleomorphic spindle and multinucleated giant cells. Some of these tumors will have incorporated adipose tissue, although these adipocytic areas lack distinct cytologic atypia and may represent entrapped normal periadnexal or subcutaneous adipose tissue. Nonetheless, owing to the similarity of some of the morphologic features of pleomorphic fibroma with cutaneous atypical lipomatous tumor, diagnostic confusion can ensue. The potential diagnostic challenges are further highlighted by a recent report of a lesion with histopathologic features of both. In response, we studied the presence of 12q15/ MDM2 amplification by fluorescence in situ hybridization and MDM2 expression by immunohistochemistry in a series of 15 pleomorphic fibromas to investigate whether these two entities share a common pathogenic origin. One case of cutaneous atypical lipomatous tumor was used as positive control for 12q15 amplification. All 15 cases were negative for MDM2 by immunohistochemistry with no demonstrable 12q15/MDM2 amplification by fluorescence in situ hybridization. Therefore, these two entities are best regarded as pathogenetically distinct. MDM2 immunohistochemistry or fluorescence in situ hybridization studies can be used to differentiate between the two if needed.

Ancillary