Elastofibroma Workup

Updated: Apr 05, 2021
  • Author: Robert A Schwartz, MD, MPH; Chief Editor: Dirk M Elston, MD  more...
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Workup

Imaging Studies

Elastofibromas have a typical sonographic appearance consisting of arrays of linear strands against an echogenic background. [30, 31] However, in some cases, the ultrasound pattern of an elastofibroma dorsi may be similar to the surrounding muscular tissue, and neither a clear cleavage surface nor a specific vascular pattern can be seen. In these cases, the elastofibroma may be difficult to distinguish from surrounding tissue. [32] If further delineating its borders proves difficult, then further imaging modalities should be used. [33]

Chest wall radiographic findings are usually normal; however, elevation of the scapula from the chest wall has been detected in a few cases. [34]

CT scanning and MRI reveal a lenticular, unencapsulated, soft tissue mass with skeletal muscle attenuation interspersed with strands of fat attenuation. [35, 36, 37] Small elastofibromas may be difficult to visualize on CT scans or MRIs, but they can be enhanced by the use of gadolinium. Its characteristic location (periscapular region) and specific imaging appearance on ultrasound images, CT scans, and MRIs facilitates accurate diagnosis. [38] Noninvasive techniques, especially MRI, and histologic assessment are closely correlated, so that sometimes a biopsy can be avoided. [39] The sensitivity and positive predictive value of MRI in the diagnosis of elastofibroma dorsi in a study of 15 patients were 93.3% (95% confidence interval, 68-100%) and 100% (95% confidence interval, 75.2-100%), respectively. [40]  CT scanning has a higher correlation than MRI in documenting the size of an elastofibroma. [41]

Incidental detection of bilateral elastofibroma dorsi with F-18 fluorodeoxyglucose positron emission computed tomography scanning has been described. [42, 43]

See the image below.

Elastofibroma. Hematoxylin and eosin stain. Interm Elastofibroma. Hematoxylin and eosin stain. Intermediate magnification. Courtesy of Soca1zim, via Wikimedia Commons.
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Procedures

A biopsy specimen should be obtained from the affected area. The surgical excision should be large and should include skin, subcutaneous fatty tissue, and, if necessary, deeper tissue. A shave or punch biopsy is not sufficient.

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Histologic Findings

The tumor grossly appears as an ill-defined mass with a white or gray-white, glistening surface.

Upon light microscopy, elastofibromas are dermal unencapsulated tumors composed of branched and unbranched elastic fibers, eosinophilic collagen bundles, and scattered fatty tissue. The elastic fibers have a degenerated, beaded appearance or are fragmented into small globules or droplets arranged in a linear pattern. The epidermis is usually unaffected. The interspersed spindle or stellate cells show a fibroblastlike appearance and were almost consistently positive for vimentin and frequently positive for CD34 and lysozyme immunohistochemically. [3] The CD105-positive vessels in elastofibromas appear to reflect active neovascularization. [44]

At an ultrastructural level, the elastic fibers appear as an irregular granular or fibrillary aggregation of electron-dense, amorphous material surrounded by microfibrils and collagen fibers. Collagen fibers are commonly incorporated within the elastic material.

Immunohistochemically, elastofibromas stain positively for vimentin but negatively for smooth muscle actin, S-100, desmin, and p53. [45] . Positive staining for factor XIIIa and CD34 in the cells forming this neoplasm implies that it originates from primitive dermal mesenchymal cells. [46]

Because of their densely fibrous nature, hypocellularity may be observed in fine-needle aspiration biopsy specimens of elastofibromas; thus, diagnostic material may be overlooked. The smears show evidence of mature adipocytes, fibroblasts, collagen fibers, globular bodies, and characteristic braidlike or fernlike structures, revealing degenerative elastic fibers. Careful evaluation of the background of the smears coupled with full knowledge of the clinical and radiological findings, including those from MRIs, is required to establish the correct diagnosis; therefore, a skin biopsy is preferable.

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