Extraneural Soft Tissue Perineurioma of the Oral Cavity: A Rare Case with Medico-Legal Implications and Literature Review

Abstract

Perineuriomas are a rare form of peripheral nerve sheath tumors, with occurrences in the oral cavity being exceptionally uncommon. This scarcity underscores the clinical significance of each documented case, as it facilitates enhanced diagnostic precision among oral health professionals. We hereby present a case involving a 68-year-old female patient with an extraneural perineurioma (EPN) located on the mandibular region. A laser-assisted excisional biopsy was performed, and the diagnosis of EPN was confirmed through histopathological examination complemented by immunohistochemical analysis. The lesion was surgically excised, and no recurrence was observed during a one-year follow-up period. Accurate recognition of EPNs in the oral cavity is crucial to prevent unnecessary aggressive surgical interventions. Misdiagnoses may occur in cases of fibromas, neurofibromas, schwannomas, ossifying fibromas, or low-grade malignancies, which can potentially result in overtreatment that may compromise both function and aesthetics. Given the rarity of oral EPN, precise diagnosis and appropriate management are essential to avoid unwarranted invasive procedures and to mitigate potential medico-legal implications originating from misdiagnosis or suboptimal treatment. Ensuring comprehensive informed consent and meticulous documentation is also vital in minimizing medico-legal risks.

Keywords: extraneural perineurioma legal implication; nerve sheath neoplasms; oncology; oral lesions; perineurioma.

Figure 1

(a). Intraoral preoperative aspect of the lesion. (b). Intraoral postoperative aspect of the lesion and aspect of the surgical specimen after removal.

Figure 2

Histologic examination revealed a circumscribed but unencapsulated submucosal hypocellular nodule composed of small spindle to ovoid cells with indistinct cell borders and long, streamer-like cell processes arranged in a short fascicular pattern within a dense sclerotic and focally fibromyxoid matrix ((A) [4× magnification] and (B) [10× magnification]). Cell pleomorphism, mitosis, and necrosis were absent. The overlying epithelium appeared unremarkable. Immunohistochemical analysis showed strong, focal cytoplasmic immunoreactivity in the neoplastic cells for GLUT-1 ((C) [10× magnification]) and weak, focal cytoplasmic immunoreactivity for AML ((D) [10× magnification]). The neoplastic cells were negative for Desmin ((E) [10× magnification]) and S100 ((F) [10× magnification]).

Figure 3

One-year follow-up.