Author: Assoc Prof Patrick Emanuel, Dermatopathologist, Auckland, New Zealand, 2013.
Perineurioma is an uncommon benign peripheral nerve sheath tumour composed exclusively of perineural cells.
Histology of perineurioma
Perineurioma tumour cells are spindle shaped, with long delicate cell processes amidst a collagenous stroma (figure 1). The spindle cells have pale open nuclei with a delicate chromatin pattern, an inconspicuous eosinophilic nucleolus and indistinct cell borders (figures 1, 2). Myxoid change may be seen and can cause diagnostic confusion (figure 3). Whorls of cells are often seen which are reminiscent of meningioma (figure 4, arrows).