Aberrant Nuclear Immunoreactivity for MDM2 in MDM2 Amplification-Negative Pleomorphic Fibroma of the Skin
Recommended Citation
Tashakori M, Pimentel J, Sanchez J, Michalowski S, Chitale D, Ormsby AH, Williamson SR. Aberrant Nuclear Immunoreactivity for MDM2 in MDM2 Amplification-Negative Pleomorphic Fibroma of the Skin. Am J Dermatopathol 2017; 39(8):e134.
Document Type
Conference Proceeding
Publication Date
8-1-2017
Publication Title
Am J Dermatopathol
Abstract
Pleomorphic fibroma of the skin is a benign fibrous neoplasm of disputed histogenesis, in which multinucleated giant cells may raise several differential diagnostic considerations, including atypical lipomatous tumor. One prior study has shown pleomorphic fibroma to be consistently negative for MDM2 immunohistochemistry. A 20-year-old African American woman presented with an asymptomatic flesh-colored 1.2 cm soft nodule on the right buttock. Clinical impression was lipoma; however, punch biopsy showed a domeshaped nodule with dense collagen, spindle-shaped cells, and scattered multinucleated atypical cells. Immunohistochemistry revealed positivity for Factor XIIIa, CD34, and MDM2. Staining for S100, neurofilament, CD68, CD31 and D2-40 was negative. Fluorescence in situ hybridization (FISH), however, was negative for 12q15 (MDM2) amplification, arguing against atypical lipomatous tumor. Cutaneous pleomorphic fibroma may occasionally demonstrate false-positive immunohistochemical labeling for MDM2, highlighting the superiority of FISH for excluding a differential diagnosis of atypical lipomatous tumor in this scenario.
Volume
39
Issue
8
First Page
e134
