Authors: Assoc Prof Patrick Emanuel, Dermatopathologist, Auckland, New Zealand, 2013.
Otherwise known as collagenous fibroma, desmoplastic fibroblastomas are benign tumours that present as slow growing masses in the subcutis and mainly occur in middle age. They have been described involving a wide range of anatomic sites but most commonly arise on the upper extremity.
Histology of desmoplastic fibroblastoma
Sections of desmoplastic fibroblastoma show a relatively well circumscribedtumour in subcutaneous adipose tissue (figure 1). The tumour is composed of fibrous or slightly myxoidconnective tissue with sparse interspersed spindled cells (figure 2). The vessels are inconspicuous but may show perivascularsclerosis. High magnification shows the spindle cells are bland, with some polygonal forms (figure 3). Mitoses are absent or extremely sparse.