Oral plexiform schwannoma: A case report and relevant immunohistochemical investigation

A rare case of intraoral schwannoma in gingiva

BACKGROUND

Schwannomas are benign, slow-growing encapsulated nodular lesions. As for the most benign encapsulated lesions, the treatment of choice is complete removal of the entire tissue with preservation of surrounding tissue.

METHODS AND RESULTS

The case presented is that of a 35-year-old female with the chief complaint of swelling on her gums in the lower left posterior region. Through intraoral and extraoral examinations the benign nature of the lesion was established. The excisional biopsy was carried out under local anesthesia, and the specimen was sent for histological examination, which gave a definite diagnosis of oral schwannoma. The patient was recalled at regular intervals so as to check for any recurrence of the lesion or occurrence of new lesions elsewhere in the body.

CONCLUSION

The present case reemphasizes the importance of thorough clinical examination along with appropriate investigations, especially histopathological and immunohistochemical, for establishing a definitive diagnosis, which eventually plays an important role in the choice and execution of appropriate treatment at the earliest for the best prognosis and outcomes.

KEY POINTS

Why is this case new information? To the best of the author's knowledge, this the first case report of oral schwannoma diagnosed in gingiva in Indian population. This case presented a diagnostic dilemma due to its unusual location. What are the keys to successful management of this case? Schwannomas when completely excised have low rate of recurrence. Accurate diagnosis of the lesion along with complete physical examination and follow-up at regular interval to rule out any recurrences are the keys to successful management of this case. What are the primary limitations to success in this case? Lack of data regarding residual tumor postoperative is a primary limitations to success of the case, as recurrence is associated with subtotal tumor removal.

Telocytes in the Normal and Pathological Peripheral Nervous System

We studied telocytes/CD34+ stromal cells in the normal and pathological peripheral nervous system (PNS), for which we reviewed the literature and contributed our observations under light and electron microscopy in this field. We consider the following aspects: (A) general characteristics of telocytes and the terminology used for these cells (e.g., endoneurial stromal cells) in PNS; (B) the presence, characteristics and arrangement of telocytes in the normal PNS, including (i) nerve epi-perineurium and endoneurium (e.g., telopodes extending into the endoneurial space); (ii) sensory nerve endings (e.g., Meissner and Pacinian corpuscles, and neuromuscular spindles); (iii) ganglia; and (iv) the intestinal autonomic nervous system; (C) the telocytes in the pathologic PNS, encompassing (i) hyperplastic neurogenic processes (neurogenic hyperplasia of the appendix and gallbladder), highly demonstrative of telocyte characteristics and relations, (ii) PNS tumours, such as neurofibroma, schwannoma, granular cell tumour and nerve sheath myxoma, and interstitial cell of Cajal-related gastrointestinal stromal tumour (GIST), (iii) tumour-invaded nerves and (iv) traumatic, metabolic, degenerative or genetic neuropathies, in which there are fewer studies on telocytes, e.g., neuroinflammation and nerves in undescended testicles (cryptorchidism), Klinefelter syndrome, crush injury, mucopolysaccharidosis II (Hunter’s syndrome) and Charcot–Marie–Tooth disease.

Plexiform Schwannoma of the Oral Cavity: Report of Eight Cases and a Review of the Literature

Plexiform schwannoma represents an unusual schwannoma variant, characterized by multinodular growth grossly and/or microscopically. A review of the English-language literature reveals only 28 previously reported cases involving the oral cavity, and herein we present 8 additional cases. Among these 36 patients, the average age at diagnosis was 28 years (range 5 to 62 years), with a female-to-male ratio of 1.4:1. The most frequently involved sites were the tongue (n = 13) and lip (n = 11). Lesion duration prior to presentation averaged 5.3 years (range, 6 weeks to 26 years). The average lesion size was 2.1 cm (range, 0.3 to 16 cm). The typical clinical presentation was a painless mass, although infrequent findings included pain/discomfort, paresthesia, difficulty chewing, and limited buccal mobility. All cases clinically appeared as a solitary mass or localized cluster of tumor nodules, with the exception of one patient who had neurofibromatosis 2 (NF2) and exhibited two distinct nodules on the tongue and buccal mucosa. In addition, extraoral neural neoplasms were evident in four patients, including three with NF2. Typical microscopic findings included multiple well-circumscribed tumor nodules, each surrounded by a perineurium-derived capsule with immunoreactivity for epithelial membrane antigen. The nodules contained characteristically bland and diffusely S-100-positive spindle cells arranged in Antoni A and B patterns; however, modest nuclear pleomorphism was evident in three cases. Most patients (n = 23) were treated by excision or enucleation and curettage, and three patients experienced recurrence. Unlike plexiform neurofibromas, plexiform schwannomas exhibit only a weak association with neurofibromatosis and have no known malignant potential.