Sandbox elastofibroma

Sandbox elastofibroma
Elastofibroma: Gross, an excellent mitral valve photo of this benign lesion. Image courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology

Patholophysiology

Microscopy

In general, the tumor is an ill defined, nonencapsulated, rubbery, and firm, white lesion with interspersed fat. The tumors can be quite large (up to 20 cm), although most are around 5 cm.

File:Hematoxylin and Eosin stained photomicrograph of an elastofibroma LDRT.tif

A high power photomicrograph of an elastofibroma.

By microscopic view, there is an admixture of heavy dense bands of collagenous tissue dissected by fat and abnormal elastic fibers. The elastic fibers are often quite large and are easily identified. The elastic fibers are coarse, thick, and darkly eosinophilic, often fragmented into globules, creating a "string of pearls" or "pipe cleaner" appearance. Because of degeneration, the elastic fibers will appear as globules with a serrated or "prickled" edge.

Histochemistry

File:Elastofibroma stained with elastic stain LDRT.tif

An elastic stain photomicrograph at high power highlighting the elastic fibers in black.

The elastic fibers will be highlighted by a Weigert or von Gieson elastic stains.

Images courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology

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  Elastofibroma

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  Elastofibroma

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  Papillary Fibroelastoma: When located on the mitral valve, these tumors are usually on the anterior leaflet of the atrial surface.