Clinicopathologic analysis of 7 cases of oral schwannoma and review of the literature

Uncommon Finding of a Soft Palate Schwannoma: A Case Report

Schwannomas are relatively slow-growing benign tumors of the nerve sheath. Approximately 25-40% of schwannomas occur in the head and neck region. However, schwannomas that present in the oral cavity are relatively rare, constituting around 1% of all described cases in the head and neck region. We report a case of a 20-year-old female who was found to have an intraoral palatal schwannoma. The patient presented with a painless swelling located on the right side of the soft palate. Investigations and management were commenced, and a computed tomography (CT) scan with contrast was done, which revealed cystic changes in a large soft palate mass lesion with a heterogeneous enhancement. The mass was surgically excised and sent for histopathological examination. The diagnosis of schwannoma was made due to the presence of the characteristic Antoni A and Antoni B areas. The immunohistochemical study done was positive for protein S-100. The postoperative follow-up went uneventful.

Auricle Schwannoma: Presentation of a Rare Case and Review of Existing Literature

Schwannomas are extremely rare over auricle. Despite the extensive somatogenic neural innervations of the pinna, schwannomas are never amongst the differentials for a benign auricular mass. Previously published articles have all agreed on the rarity of this lesion occurring over the auricle. However, none of the articles have tackled and extensively reviewed the auricle schwannomas (AS) as an individual entity. The article aim to review previously published cases of AS along with an illustrative case, and provide a better insight regarding demographic, clinicopathological and immunohistochemical features of this neural tumor in a rare site. A systemic review of English literature was performed after using a sensitive search strategy involving three different databases (PubMed, Google Scholar and Embase). A total of nine cases were included. They mostly presented in young adults as a slow growing tumor (mean duration: 3.17 years) and showed a slightly higher male predominance (male/female ratio 1.25:1). They were mostly located over lateral surface (66.67%) with a predilection for left ear (77.78%). Conventional histological variant has only been reported. Complete surgical excision was performed for all the cases without any reports of recurrence or malignant transformation. AS present as a solitary, painless, firm and well-encapsulated lesion, mostly over the lateral auricle surface. Preoperative clinical diagnosis is difficult and radiological investigations do not hold much importance. FNAC is inconclusive and diagnosis mandates histopathologic examination. The nerve of tumor origin is difficult to precisely identify. Complete surgical excision is the treatment of choice. Post-operative prognosis is excellent.

Focused ultrasound ablation of a large canine oral tumor achieves efficient tumor remission: a case report

Purpose: Oral cancers are one of the commonly diagnosed tumors worldwide in human and veterinary patients. Most oral cancers are surgically resected; however, obtaining an adequate margin of safety in patients without compromising their quality of life is often challenging. Herein, we investigated the ability of non-invasive focused ultrasound (FUS) to thermally ablate a biopsy confirmed canine oral cancer. Materials and Methods: A male canine patient with a large neurilemmoma (schwannoma) mass on the left maxilla, with evidence of thinning and loss of alveolar bone and pressure necrosis, was treated with FUS ablation instead of the traditional maxillectomy procedure. FUS ablations were performed in three sessions over three weeks. Tumor remission was determined with computed tomography and histopathological examination of the treated site. Additionally, the anti-tumor immune effects of FUS were assessed by flow cytometry analysis of blood and tumor samples. Results: Complete tumor remission was noted at the treated site. Treatment related adverse events were primarily thermal burns of the buccal mucosa, which were managed with periodic hyperbaric oxygen therapy and surgical coverage of the underlying exposed bones with gingival flaps. Enhanced proliferation of adaptive immunity cells (e.g., T-cells) was observed in tumor and blood samples. Conclusion: Our limited investigation in a canine oral cancer patient suggests that FUS may avoid the need for large-scale resection of bony tissues, thus potentially improving quality of life.

Oral neural tumors: Clinicopathologic analysis of 157 cases and review of the literature

Background

Oral neural tumors (ONTs) are rare lesions and represent reactive or neoplastic proliferations of nerve sheath cells. The purpose of the present study is to report the clinical, demographic and histopathologic features of 157 ONTs diagnosed in a single Oral Pathology Department and review the pertinent literature.

Material and Methods

157 cases of ONTs diagnosed during a 44-year period were retrospectively collected and the diagnosis was reconfirmed by studying representative haematoxylin and eosin stained tissue sections. The patients’ gender and age, as well as the main clinical features of the lesions, were retrieved from the biopsy submission forms.

Results

The 157 ONTs represented approximately 0.4% of 35,590 biopsies accessioned during the study period. They affected 71 male and 86 female patients with a mean age of 38.4±18.8 years. They mainly appeared as asymptomatic nodules of normal or white colour on the tongue, lip mucosa and hard palate. The most common ONT was granular cell tumour (38.9%) followed by neurofibroma (19.7%), schwannoma (15.9%), traumatic neuroma (15.9%), palisaded encapsulated neuroma (8.3%) and nerve sheath myxoma (1.3%).

Conclusions

This study confirmed the rarity of ONTs. Their clinical characteristics mimic other oral lesions; thus, microscopic examination is the only mean to arrive at a definitive diagnosis.

Key words:Oral neural tumors; oral neural neoplasms; neurofibroma; oral neurofibroma; schwannoma; oral schwannoma; neurilemmoma; oral neurilemmoma; granular cell tumor; oral granular cell tumor; traumatic neuroma; oral traumatic neuroma; palisaded encapsulated neuroma; oral palisaded encapsulated neuroma.

Palatal Schwannoma: An Analysis of 45 Literature Reports and of an Illustrative Case

Introduction  Schwannomas are benign tumors originating from differentiated Schwann cells. Being the least common intraoral neoplasm of neural origin, it is rarely seen in the palate. The literature lacks an extensive review of intraoral schwannoma confined to the palate.

Objective  To review previously reported cases of palatal schwannoma along with an illustrative case, and to provide a better insight regarding clinicopathological and radiological features of this neural tumor in a rare intraoral site.

Data Synthesis  We present a case of palatal schwannoma in a 16-year-old female. An additional 45 cases were identified in 2 medical database searches (PubMed and Google Scholar) published from the year 1985 onwards, and from 13 countries, in the 5 continents. The ages of the patients ranged from 3 to 84 years old. Palatal schwannoma showed a slight predilection to females, with a male/female ratio of ∼ 1:1.81. Hard palate involvement is almost twice greater than soft palate involvement. Surgical excision was employed in almost all of the cases, and recurrence was reported only once.

Conclusion  Palatal schwannomas, although rare, have been reported both over the hard and the soft palate. They mostly present as a painless, firm, well-encapsulated, slow-growing solitary lesion over the lateral palatal aspect.

Imaging can add to suspicion and can delineate a differential diagnosis, but the diagnosis is confirmed by pathological examination. Fine-needle aspiration cytology (FNAC) is almost always inconclusive. Immunohistochemistry can assist in confirming a diagnosis, but is more important to rule out close differentials. Complete surgical excision is the treatment of choice, and recurrence or malignant transformation are extremely rare.

Ancient Schwannoma: A Rare Intramural Intra-lingual Lesion

Ancient schwannoma is an uncommon schwannoma variant which is a benign tumour of Schwann cell origin. It is relatively a rare tumour (25%) in the head and neck region. It is encapsulated and well demarcated from the surrounding tissues. A 35 years old patient in this case presented with painless swelling of the tongue. Trans-oral excision of the intramural lesion was performed. Histopathological and immuno-histochemistry confirmed the diagnosis of schwannoma. This case is of interest on account of the complexity of its diagnosis and the atypical site, that is, intra-mural, of appearance of a schwannoma.

Oral plexiform schwannoma: A case report and relevant immunohistochemical investigation

Schwannomas are benign peripheral nerve sheath tumors originating from the Schwann cells. Most schwannomas in the head and neck region are solitary; however, multiple schwannomas affecting one or more nerves suggest a possible association with neurofibromatosis type 2 and schwannomatosis. Plexiform schwannoma is a rare variant of conventional schwannoma that is characterized by intraneural multinodular growth. This grow pattern has also been observed with other neural tumors which may make diagnosis more difficult. Herein, we report the case of a 28-year-old woman who presented a solitary plexiform schwannoma of great palatine nerve. In the present case, we focused on immunohistochemical analysis in daily practice for the differential diagnosis of schwannomas and their mainly morphological mimics, especially with plexiform neurofibroma, granular cell tumor and malignant peripheral nerve sheath tumors. We also discussed on SMARBC1/IN1 marker usefulness in combination with brain magnetic resonance imaging for the distinction of solitary schwannoma from neurofibromatosis type 2 or schwannomatosis.

Comprehensive Analyses of Intraoral Benign and Malignant Nerve Sheath Tumors: The Rare Disease Entities Revisited

INTRODUCTION

Intraoral benign and malignant nerve sheath tumors (BNST and MNST) are rare tumors with non-specific clinical presentations and represent diagnostic and therapeutic challenges. Current knowledge regarding their demographic, clinicopathological features and treatments remains fragmented.

MATERIALS AND METHODS

The original data about patients diagnosed as intraoral BNST and MNST were retrieved from our disease registry (2005-2017). Comprehensive reviews of English and Chinese literature were performed to collect and analyze the epidemiological, clinicopathological data and treatment outcomes about those published cases.

RESULTS

Thirty-four intraoral BNSTs were found at our institution in the past 13 years. Literature reviews identified 354 intraoral BNSTs in 223 articles and 60 intraoral MNSTs in 50 articles. Most intraoral BNSTs and MNSTs were presented in the second to fifth decade of life. Males outnumbered females in MNSTs, while BNSTs displayed a slight female preponderance. The common sites for intraoral BNSTs were parapharyngeal space followed by tongue, whereas mandible was the most common site for MNSTs. Most intraoral BNSTs were presented as slow-growing, painless mass or swelling, while MNSTs usually appeared as painful and invasive mass with discomfort. Surgical excision was preferred for intraoral BNSTs with excellent prognosis. Complete resection was indicated for intraoral MNST with dismal prognosis as evidenced by much recurrence, metastasis, and death.

CONCLUSION

Intraoral BNST and MNST are rare diseases which should not be ignored when intraoral painless or painful mass/swelling is found. Surgical excision is indicated for intraoral BNST with favorable outcomes. However, further investigations are warranted to optimize the treatment for intraoral MNST to improve its prognosis.

Evaluation and Management of Facial Nerve Schwannoma

Facial nerve schwannomas are benign peripheral nerve sheath tumors that arise from Schwann cells, and most commonly present with facial paresis and/or hearing loss. Computed tomography and MRI are critical to diagnosis. Management decisions are based on tumor size, facial function, and hearing status. Observation is usually the best option in patients with good facial function. For patients with poor facial function, the authors favor surgical resection with facial reanimation. There is growing evidence to support radiation treatment in patients with progressively worsening moderate facial paresis and growing tumors.

Palatal schwannoma in a young female patient: report of a case and review of the literature

BACKGROUND

A few cases of oral schwannomas in paediatric patients have appeared in the literature so far; however, there are no studies focusing solely on paediatric oral schwannomas. The aim of this study is to report a case of palatal schwannoma in a young female patient and review the pertinent literature on oral schwannomas in paediatric patients.

CASE REPORT

A 12-year-old girl presented with a growing swelling of 2 weeks duration on the hard palate. With a provisional diagnosis of a salivary gland neoplasm an incisional biopsy was performed under local anesthesia and the histologic examination disclosed an Antony A type schwannoma.

TREATMENT

Complete surgical resection of the lesion was performed under local anaesthesia through a palatal mucosa incision and paraffin gauze was sutured on the surgical area for protection during secondary healing. The bone underlying the tumor was normal. The postoperative period was uneventful and 2 weeks after excision the gauze were removed.

FOLLOW-UP

There have been no signs of recurrence during a 18-month follow up period.

CONCLUSION

A palatal swelling in a child or adolescent may represent a neoplasm, such as a schwannoma and requires careful clinical and radiographic evaluation of the dentition.

Schwannoma of the hard palate

Schwannomas are benign encapsulated perineural tumors. The head and neck region is the most common site. Intraoral origin is seen in only 1% of cases, tongue being the most common site; its location in the palate is rare. We report a case of hard-palate schwannoma with bony erosion which was immunohistochemically confirmed. The tumor was excised completely intraorally. After two months of follow-up, the defect was found to be completely covered with palatal mucosa.

Schwannoma in the midline of hard palate: a case report and review of literature

Schwannoma is a benign encapsulated slow-growing tumor that originates from Schwann cells of the peripheral nerve sheath. It usually occurs in the head and neck; however, it is rare in the oral cavity. The tongue is the most common site of intraoral schwannomas, followed by the floor of the mouth, palate, gingiva, vestibular mucosa, lips and mental nerve area. We report a rare case of schwannoma in the midline of hard palate with ulcerated surface in a 21-year-old male with a two-month history of a painless swelling on his palate. Clinical, radiographic and histopathological features along with differential diagnosis and treatment are also discussed.

Intraoral Schwannomas: Presentation of a series of 12 cases

Introduction: Schwannomas are benign and not very frequent tumors of the peripheral nerves, derived from the nerve supporting Schwann cells. Study Design: Data were collected on the clinical manifestations (sex, age), location, size and symptonts of the lesions as well as the evolution time and the initial (presumption) diagnosis. Results: Twelve patients were documented, with a mean age of 29,5 ± 12,1 years (range 16-50) and a balanced gender distribution. The mean duration of the lesions was 42,17± 45,3 months. The lesion located in the floor of the mouth was the largest tumor, measuring about 4 cm in maximum diameter, while the average size of the 12 schwannomas was 2.04± 1.1 cm. Conclusion: We present 12 oral schwannomas diagnosed and treated over a period of 10 years.

Key words:Schwannomas, oral benign tumor, neurilemmoma.

Multiple schwannomas of the upper limb related exclusively to the ulnar nerve in a patient with segmental schwannomatosis

Schwannomas are benign encapsulated tumours arising from the sheaths of peripheral nerves. They present as slowly enlarging solitary lumps, which may cause neurological defects. Multiple lesions are rare, but occur in patients with neurofibromatosis type 2 or schwannomatosis. Positive outcomes have been reported for surgical excision in solitary schwannomas. However, the role of surgery in patients with multiple lesions is less clear. The risk of complications such as iatrogenic nerve injury and the high likelihood of disease recurrence mean that surgical intervention should be limited to the prevention of progressive neurological deficit. We report a case of a 45 year old male who presented with multiple enlarging masses in the upper limb and sensory deficit in the distribution of the ulnar nerve. The tumours were found to be related exclusively to the ulnar nerve during surgical exploration and excision, a rare phenomenon. The masses were diagnosed as schwannomas following histopathological analysis, allowing our patient to be diagnosed with the rare entity segmental schwannomatosis. One year post-operatively motor function was normal, but intermittent numbness still occurred. Two further asymptomatic schwannomas developed subsequently and were managed conservatively.

Intraoral schwannoma: a case report

Schwannoma (neurilemmona) is a benign nerve sheath composed of Schwann cells. This tumor represents 1% of all benign tumor, usually observed in the head and neck region, and in, rare cases, this lesion may be observed in oral cavity. They are usually asymptomatic, do not recur, and malignant transformation is rare. We presented a case report of schwannoma in the lower lips.

[Tongue base schwannoma in a child]

INTRODUCTION

A schwannoma is a benign slow growing tumor originating from the peripheral nerve sheath. Its tongue base location is extremely rare, especially in very young patients.

CASE REPORT

A 15-year-old female patient was admitted in emergency for moderate hematemesis. The clinical examination revealed swelling of the tongue base, causing the bleeding. This lesion had appeared when she was 3years of age and no treatment was done. A complete surgical excision was performed and the histopathological examination allowed diagnosing a tongue base schwannoma. The postoperative outcome was uneventful, and no recurrence was detected 6months after surgery.

DISCUSSION

The particularities of this report are the patient's very young age and the tumor's tongue base location. The prognosis is usually good after complete excision, if there is only one tumor. Type 2 neurofibromatosis should be excluded, given the risk of malignant degeneration.