Elastofibroma usually presents on the back (usually in the subscapular region) as a poorly defined mass or pseudotumour. It is also called elastofibroma dorsi. Repetitive manual labour is thought to give rise to degeneration of elastic and fibrous tissues.
Histology of elastofibroma
In elastofibroma, the histopathology shows dense accumulation of eosinophilic tissue irregularly interdigitated into adipose tissue (figure 1). A higher power examination shows collagen bundles that alternate with large, thick eosinophilic elastic fibres (figures 2–4).
Special studies for elastofibroma
Elastic stains can be used to highlight the morphology of the abnormal elastic fibres. The elastic fibres may be fragmented into linear globules, which are described as beads on a string.
The differential diagnosis for elastofibroma
Other diagnoses to be considered include:
- Nuchal fibroma — these typically don’t have the characteristic abnormal elastic fibres seen in elastofibroma.
- Desmoid fibromatosis — this is more cellular and infiltrates skeletal muscle; the characteristic abnormal elastic fibres seen in elastofibroma are absent.