Case Report: Calcifying Fibrous Pseudotumor: An Ultrastructural Study

Abstract

To clarify the pathogenesis of calcification in calcifying fibrous pseudotumor (CFT), the lesion arising in the chest wall of a 16-month-old boy was ultrastructurally investigated. Fibroblasts were surrounded by large amounts of collagen fibrils. The dystrophic and psammomatous calcifications were observed as electron-dense amorphous masses and laminated bodies, respectively, within the cytoplasm of fibroblasts and in the collagenous stroma. The degeneration of cytoplasm seemed to be an initial event of intracytoplasmic calcification. Extracellular calcified substances often abutted to fibroblasts. Fibroblasts may play an important role in both intracellular and extracellular calcifications of CFT.

Calcifying fibrous tumor of the clivus presenting in an adult

“…The classic radiological image shows a skull base chordoma which is a destructive soft tissue mass with speckles of bone within a minimally enhancing tumor on CT scan. On MRI the chordomas may be similar to CFT [13], [14]. However, we can distinguish CFT from chordomas by histopathologically because cells with foamy and bubbly cytoplasm can be found in chordomas [15].…”

“…Fibroblasts do express vimentin. You can see the immune expression of factor XIIIa and CD34 on rare occasions [13], [17].…”