Intraneural Perineurioma:A Clonal Neoplasm Associated With Abnormalities of Chromosome 22

Abstract

The nature of perineurioma, variably termed "localized hypertrophic neuropathy," "intraneural neurofibroma," and "hypertrophic interstitial neuritis" has long been an issue of contention. Most authors consider it a neoplasm, but some a reactive process. Eight clinically and morphologically typical perineuriomas were studied by histologic, immunohistochemical and ultrastructural methods. One perineurioma was subject to tissue culture and cytogenetic study and another to fluorescence in situ hybridization (FISH) analysis. The patients, 3 males and 5 females, ranged in age from 11 to 38 years. All tumors were intraneural, and involved extremities (2 sciatic, 1 median, 1 femoral, 1 peroneal, 1 brachial plexus, 1 ulnar, and 1 radial). Neurologic symptoms, motor in all cases and sensory in 4, were present from 1 month to 7 years (mean 1.2 years). Fusiform, segmental nerve enlargement was clinically apparent in only two patients, but was evident on MRI in five of eight patients. Lesion length ranged from 3.5 to 30 cm, the largest involving the sciatic nerve from the obturator foramen to the knee. One lesion involved two nerve roots, but no association with a phakomatosis was noted. Treatment consisted of biopsy in six cases and resection in two cases. Histologically, pseudo-onion bulbs composed of epithelial membrane antigen-reactive, S-100 protein-negative perineurial cells surrounded myelinated or nonmyelinated nerve fibers. Many were accompanied by their S-100 protein-positive Schwann sheaths. Some whorls lacked a central axon. A single mitosis was noted in one case. The MIB-1 antigen labelling index ranged from 4% to 17%. Staining for p53 antigen in six cases showed no (2 of 6), rare (2 of 6), or scattered (2 of 6) immunoreactive nuclei. Cytogenetic analysis in one case demonstrated a chromosomally abnormal clone. Each of 16 metaphases was abnormal; the tumor cells appeared to be homozygously deficient for the region 22q11.2qter. In another case, 53% of interphase nuclei showed three FISH signals with a chromosome 14/22 probe, thus suggesting either monosomy for the centromere of chromosome 14 or that of chromosome 22.(ABSTRACT TRUNCATED AT 400 WORDS)

Intraoral Pseudo-Onion Bulb Intraneural Proliferations in a Patient with Hemimandibular Hyperplasia: A Case Report and Review of the Literature

“…In 1995, Emory et al [9] demonstrated the clonal nature of the intraneural perineurioma and its association with abnormalities of chromosome 22. Giannini et al [8] also showed a deletion of part or all of chromosome 22 in extraneural perineuriomas and supported the view that both types of perineuriomas are neoplasms of perineurial cells.…”

“…Therefore, three other useful but nonspecific stains cited in the literature that can aid in diagnosis are Glut-1, claudin-1, and collagen type-IV [1,2,4,7]. Perineuriomas are ultrastructurally and immunohistochemically similar to normal perineurial cells, but are clonal, frequently reported to demonstrate a deletion of the region of chromosome 22 where the tumor suppressor gene NF2 resides [1,2,5,[7][8][9][10].…”

Medial Elbow Mass in an 18-year-old Woman

“…In one study, a predilection for the upper extremity was reported [6]; however, research has found a nearly equal incidence of upper and lower extremity involvement [12][13][14]. The definitive cause of these tumors is still being investigated [5,10].…”

Perineurioma esclerosante: relato de caso e revisão da literatura

“…8 Tipicamente, uma proliferação de células perineurais de formato fusiforme ocorre no corpo de um tronco nervoso e se dispõe em redemoinhos concên-tricos ao redor de axônios e células de Schwann preexistentes e comprimidos. Esse padrão é observado mais facilmente nos cortes transversais.…”