Diagnosis and surgical outcomes of intraparotid facial nerve schwannoma showing normal facial nerve function

Intranodal palisaded myofibroblastoma in the submandibular gland region: a case report

Intranodal palisaded myofibroblastoma (IPM) is a rare benign tumor of the lymph nodes, particularly in inguinal lymph nodes. IPM originating from the submandibular gland lymph nodes is rarely encountered in clinical practice. Herein, we report the case of a 31-year-old male patient with IPM of the submandibular gland region and describe in detail magnetic resonance imaging findings and pathology. Magnetic resonance imaging detected a heterogeneous lesion with a hypointense rim on T2-weighted imaging with specificity in the left submandibular gland region. This case report will contribute to the accumulation of experience in the diagnosis of this disease.

Imaging of Temporal Bone Mass Lesions: A Pictorial Review

Tumoral lesions of the temporal bone include benign or malignant tumors and congenital or inflammatory lesions. Temporal bone lesions are difficult to approach. Therefore, making a preoperative diagnosis and considering whether the lesions require treatment are necessary; if they require treatment, then the type of treatment requires consideration. These tumors cannot be observed directly and must be diagnosed based on symptoms and imaging findings. However, the differentiation of temporal bone lesions is difficult because they are rare and large in variety. In this pictorial review, we divided temporal bone lesions by location such as along the facial nerve, along the internal jugular vein, around the endolymphatic sac, in the internal auditory canal/cerebellopontine angle, petrous apex, middle ear, and mastoid, focusing on the imaging findings of temporal bone lesions. Then, we created a diagnostic flowchart that suggested that the systematic separation of imaging findings is useful for differentiation. Although it is necessary to make comprehensive judgments based on the clinical symptoms, patient background, and imaging findings to diagnose temporal bone mass lesions, capturing imaging features can be a useful differentiation method.

Systematic Review of Intra Parotid Facial Nerve Schwannoma and a Case Report

To evaluate the clinico-epidemiological aspects, pathological features, diagnostic methods, management protocol and functional outcome of the intra-parotid facial nerve schwannoma (IFNS) and to present a case report on intra parotid facial nerve schwannoma. PubMed, ProQuest, Google scholar, Science direct and Scopus were screened for studies. Article selection and data extraction was done by one investigator and other investigator confirmed its accuracy. After abstract and text screening a total of 69 articles were finally selected for the study with the inclusion and exclusion criteria of the systematic review as per PRISMA guidelines. With addition of one case reported to our department. The mean age of diagnosis was 43 ± 16 years with a slight female predominance. The mean duration of the tumour was 29.5 months and the mean size of the tumour on initial diagnosis was 3.6 ± 1.67 cm. Pleomorphic adenoma was the primary diagnosis in 44 cases. Superficial parotidectomy was done in 64 cases followed by resection in 47 cases. Reconstructive treatment was carried out by an end-to-end anastomosis in 3 patients and by facial-hypoglossal anastomosis in 16 patients, GAN cable grafting in 5 patients, a greater auricular nerve graft was done in18 patients and end-to-side interposed sural nerve graft in 8 patients. The type D tumours are treated by extended resection of the facial nerve, which is difficult to reconstruct and also employs a nerve graft that does not often give acceptable recovery of facial function. Facial nerve schwannomas being a rare entity poses a dilemma in diagnosis and management. Managing the lesions is also difficult as intraoperative adherence to the nerve makes a tumour free margin difficult without sacrificing the nerve. At present there is no consensus regarding the management of various types of intra-parotid facial nerve shwannoma.

Facial Schwannoma Management Outcomes: A Systematic Review of the Literature

OBJECTIVE

To evaluate facial nerve outcomes of various management strategies for facial schwannomas by assimilating individualized patient data from the literature to address controversies in management.

DATA SOURCES

PubMed-National Center for Biotechnology Information and Scopus databases.

REVIEW METHODS

A systematic review of the literature was performed for studies regarding facial schwannomas. Studies were included if they presented patient-level data, type of intervention, pre- and postintervention House-Brackmann (HB) grades, and tumor location by facial nerve segment.

RESULTS

Individualized data from 487 patients were collected from 31 studies. Eighty (16.4%) facial schwannomas were managed with observation, 25 (5.1%) with surgical decompression, 20 (4.1%) with stereotactic radiosurgery, 225 (46.2%) with total resection, and 137 (28.1%) with subtotal resection/stripping surgery. Stripping surgery/subtotal resection with good preoperative facial nerve function maintained HB grade 1 or 2 in 96% of cases. With a total resection of intradural tumors, preoperative HB grade did not significantly affect facial nerve outcome (n = 45, P = .46). However, a lower preoperative HB grade was associated with a better facial nerve outcome with intratemporal tumors (n = 56, P = .009). When stereotactic radiosurgery was performed, 40% of patients had improved, 35% were stable, and 25% had worsened facial function. Facial nerve decompression rarely affected short-term facial nerve status.

CONCLUSION

The data from this study help delineate which treatment strategies are best in which clinical scenarios. The findings can be used to develop a more definitive management algorithm for this complicated pathology.

Intraparotid facial nerve schwannoma: a 17-year, single-institution experience of diagnosis and management

BACKGROUND

Intraparotid facial nerve schwannoma (IFNS) is rare and its definite preoperative diagnosis is challenging.

OBJECTIVE

To improve available knowledge regarding the diagnosis of IFNS and to suggest an appropriate treatment plan.

MATERIAL AND METHODS

We retrospectively analyzed medical records of IFNS patients at our hospital. Inclusion criteria were surgery (from January 2000, to December 2016) for a parotid mass, pathologically diagnosed as a schwannoma.

RESULTS

The study included 42 eligible patients who had undergone tumor resection from 5977 parotid tumor patients. Mostly presented hard-textured (18/39) or medium-textured (15/39), with limited mobility (21/39) mass (three tumors were not palpable). Their facial nerve function outcomes were House-Brackmann Grade I (n = 14), Grade II (n = 7), Grade III (n = 11), Grade IV (n = 5), Grade V (n = 3), and Grade VI (n = 2). Significant differences were noted in results based on different surgical methods used (p = .000) and tumor involvement (p = .002).

CONCLUSIONS AND SIGNIFICANCE

A hard-textured tumor with limited mobility mass in the parotid gland should prompt the diagnosis of a schwannoma. Tumors involving main trunk usually lead to unsatisfactory facial nerve outcomes. Facial nerve preservation should always be essential, and stripping surgery or intracapsular enucleation could be the preferred surgical methods of choice.

Intraparotid Facial Nerve Schwannoma in a Nine-Year-Old Patient: Diagnosis, Classification, and Surgical Approach Stages

Intraparotid facial nerve schwannoma (IFNS) is rarely observed in children compared with adults. Only a few cases have been reported in the literature. After radiological imaging and fine needle aspiration biopsy, an IFNS diagnosis may be skipped and confused with pleomorphic adenoma, which has a high prevalence among patients who have a mass in the parotid gland. The probability of IFNS can be recognized by a close relation between the mass and the facial nerve during the application of parotidectomy and by the frozen biopsy of the mass. The surgeon evaluates the mass and faces with surgical mass excison and facial nerve reconstruction according to the relation between the mass and the facial nerve because there is no diagnostic method for the presurgery diagnosis of IFNS. Therefore, the surgeon should be prepared for the possibility of functional lossin the facial nerve during parotidectomy. This article presents the case of a 9-year-old patient with an IFNS diagnosis who had a surgical operation in our clinic, and the algorithm designed according to the literature for the diagnosis and surgical classification of IFNS, as well as the approaches to facial nerve reconstruction.

The Natural History of Facial Schwannomas: A Meta-Analysis of Case Series

Objective  This study is to establish predictors of facial paralysis and auditory morbidity secondary to facial schwannomas by assimilating individualized patient data from the literature. Design  A systematic review of the literature was conducted for studies regarding facial schwannomas. Studies were only included if they presented patient level data, House-Brackmann grades, and tumor location by facial nerve segment. Odds ratios (OR) were estimated using generalized linear mixed models. Main Outcome Measures  Facial weakness and hearing loss. Results  Data from 504 patients were collected from 32 studies. The geniculate ganglion was the most common facial nerve segment involved (39.3%). A greater number of facial nerve segments involved was positively associated with both facial weakness and hearing loss, whereas tumor diameter did not correlate with either morbidity. Intratemporal involvement was associated with higher odds of facial weakness (OR = 4.78, p  < 0.001), intradural involvement was negatively associated with facial weakness (OR = 0.56, p  = 0.004), and extratemporal involvement was not a predictor of facial weakness (OR = 0.68, p  = 0.27). The odds of hearing loss increased with more proximal location of the tumor (intradural: OR = 3.26, p  < 0.001; intratemporal: OR = 0.60, p  = 0.14; extratemporal: OR = 0.27, p  = 0.01). Conclusion  The most important factors associated with facial weakness and hearing loss are tumor location and the number of facial nerve segments involved. An understanding of the factors that contribute most heavily to the natural morbidity can help guide the appropriate timing and type of intervention in future cases of facial schwannoma.

Peripheral nerve sheath tumors arising in salivary glands: A clinicopathologic study

Primary salivary gland peripheral nerve sheath tumors (PNST) are uncommon. This study is a retrospective, clinicopathologic review of 9 cases of PNST (5 neurofibromas, 3 schwannomas and 1 malignant peripheral nerve sheath tumor (MPNST)) arising from the salivary glands, encountered between 1990 and 2015. All patients with neurofibromas were male (ages 1-62 years) and had a single parotid lesion of which 2 were diffuse, 2 plexiform and one mixed diffuse/plexiform. Four had a history of neurofibromatosis I. Four of 5 presented with symptoms related to mass effect including facial swelling, facial drooping, and dysphagia. All underwent de-bulking surgery and recurred due to continued growth. Of the 3 patients with schwannomas, 1 was male and 2 were female (ages 19, 44 and 56 years). One tumor each arose in the sublingual, submandibular, and parotid glands. Two of 3 presented with soreness and swelling local to the affected gland, especially while chewing. There was no recurrence of these tumors after resection. An MPNST in a male presented as a tender mass in the patient's left parotid; the tumor was resected. There was no evidence of tumor elsewhere in the body. The tumor did not recur in 12 years of follow-up. The most common tumor type in the current series was neurofibroma; most arose in the background of neurofibromatosis type I and all of which recurred after initial subtotal resection. Most PNST arose in the parotid gland.

Clinical Retrospective Analysis of 9 Cases of Intraparotid Facial Nerve Schwannoma

PURPOSE

The management of intraparotid facial nerve schwannoma (IFNS) is challenging because it is extremely rare and often misdiagnosed as pleomorphic adenoma or another parotid tumor. The purpose of this study was to report on the authors' experience in the treatment of IFNS and to review the literature regarding the diagnosis and management of IFNS.

MATERIALS AND METHODS

From January 1997 through October 2015, 916 consecutive parotidectomies were performed at Shenzhen People's Hospital (Shenzhen, China). Of 916 parotid tumors samples, 9 cases of IFNS confirmed by histopathology were identified and analyzed retrospectively. In addition, 161 published cases from 1956 through 2015 were systematically reviewed.

RESULTS

Nine cases of IFNS were identified from 916 parotid tumors samples and accounted for 0.98% of all parotid tumors. All these patients with IFNS underwent tumor removal and parotidectomy with preservation of facial nerve (FN) continuity. The mean follow-up period was 6.2 years (range, 1 to 16 yr). Facial function improved gradually from House-Brackmann grade (HBG) II to III immediately postoperatively to HBG I during the subsequent 3 to 9 months in all cases. Tumor recurrence with stylomastoid foramen involvement was observed in 1 case 3 years after surgery. The others remained free of recurrence. Of 161 IFNS cases reported in the literature, 17 cases with facial paresis were found to have intra-temporal involvement, but no facial paresis was found in patients with intraparotid involvement only.

CONCLUSIONS

An IFNS is easily misdiagnosed as pleomorphic adenoma or Warthin tumor preoperatively; the correct diagnosis for IFNS depends mainly on intraoperative observation of the gross relation between the tumor and the FN or excision frozen biopsy examination. The integrity of the FN should be preserved for patients with IFNS and without facial paresis, whenever possible.

Intraparotid Facial Nerve Schwannoma

Intraparotid facial nerve schwannoma is a rare benign neoplasm. Due to its rarity, it is not usually a prioritized diagnosis before surgery and may therefore lead to an unintentional treatment error. In this article, we report a single case of intraparotid facial nerve schwannoma. We were able to make a diagnosis with frozen biopsy. A complete resection of the mass while preserving the facial nerve was performed. Herein we present our clinical experience with regards to the treatment process of intraparotid facial nerve schwannoma.