Schwannoma is a benign tumor rarely found in the head and neck and much less commonly found in the intraparotid facial nerve. It is a slow-growing encapsulated tumor originating from the Schwann cells or axonal nerve sheath. It can occur anywhere along the course of the facial nerve. Patients may present with symptoms of facial palsy, but the most common presenting symptom is an asymptomatic swelling. Diagnosis is usually difficult before surgical removal and histopathological examination. We report a rare case of intraparotid facial nerve schwannoma in a 57-year-old female who had sustained a mass of the right preauricular area for 3 years. She reported no pain or facial muscle weakness. Enhanced computed tomography findings revealed the impression of pleomorphic adenoma. However, intraoperative gross findings were not characteristic of pleomorphic adenoma, and a frozen biopsy was performed resulting in the impression of a nerve sheath tumor. We performed an extracapsular surgical excision without parotidectomy. Permanent histopathology and immunohistochemistry reports diagnosed the mass as schwannoma. There were no complications including facial palsy after surgery. No recurrence was found at 6 months after surgery
Adenoma, Pleomorphic ; Axons ; Biopsy ; Diagnosis ; Facial Muscles ; Facial Nerve ; Facial Paralysis ; Female ; Head ; Humans ; Immunohistochemistry ; Middle Aged ; Neck ; Neurilemmoma ; Parotid Gland ; Recurrence ; Schwann Cells

PURPOSE: The aim of this study was to review the common conditions associated with mandibular canal widening. MATERIALS AND METHODS: General search engines and specialized databases including Google Scholar, PubMed, PubMed Central, Science Direct, and Scopus were used to find relevant studies by using the following keywords: “mandibular canal,” “alveolar canal,” “inferior alveolar nerve canal,” “inferior dental canal,” “inferior mandibular canal,” “widening,” “enlargement,” “distension,” “expansion,” and “dilation.” RESULTS: In total, 130 articles were found, of which 80 were broadly relevant to the topic. We ultimately included 38 articles that were closely related to the topic of interest. When the data were compiled, the following 7 lesions were found to have a relationship with mandibular canal widening: non-Hodgkin lymphoma, osteosarcoma, schwannoma, neurofibroma, vascular malformation/hemangioma, multiple endocrine neoplasia syndromes, and perineural spreading or invasion. CONCLUSION: When clinicians encounter a lesion associated with mandibular canal widening, they should immediately consider these entities in the differential diagnosis. Doing so will help dentists make more accurate diagnoses and develop better treatment plans based on patients' radiographs.
Dentists ; Diagnosis ; Diagnosis, Differential ; Humans ; Lymphoma, Non-Hodgkin ; Mandibular Nerve ; Multiple Endocrine Neoplasia ; Neurilemmoma ; Neurofibroma ; Odontogenic Cysts ; Odontogenic Tumors ; Osteosarcoma ; Search Engine

BACKGROUND: Pathologic diagnosis of central nervous system (CNS) neoplasms is made by comparing light microscopic, immunohistochemical, and molecular cytogenetic findings with clinicoradiologic observations. Intraoperative frozen cytology smears can improve the diagnostic accuracy for CNS neoplasms. Here, we evaluate the diagnostic value of cytology in frozen diagnoses of CNS neoplasms. METHODS: Cases were selected from patients undergoing both frozen cytology and frozen sections. Diagnostic accuracy was evaluated. RESULTS: Four hundred and fifty-four cases were included in this retrospective single-center review study covering a span of 10 years. Five discrepant cases (1.1%) were found after excluding 53 deferred cases (31 cases of tentative diagnosis, 22 cases of inadequate frozen sampling). A total of 346 cases of complete concordance and 50 cases of partial concordance were classified as not discordant cases in the present study. Diagnostic accuracy of intraoperative frozen diagnosis was 87.2%, and the accuracy was 98.8% after excluding deferred cases. Discrepancies between frozen and permanent diagnoses (n = 5, 1.1%) were found in cases of nonrepresentative sampling (n = 2) and misinterpretation (n = 3). High concordance was observed more frequently in meningeal tumors (97/98, 99%), metastatic brain tumors (51/52, 98.1%), pituitary adenomas (86/89, 96.6%), schwannomas (45/47, 95.8%), high-grade astrocytic tumors (47/58, 81%), low grade astrocytic tumors (10/13, 76.9%), non-neoplastic lesions (23/36, 63.9%), in decreasing frequency. CONCLUSIONS: Using intraoperative cytology and frozen sections of CNS tumors is a highly accurate diagnostic ancillary method, providing subtyping of CNS neoplasms, especially in frequently encountered entities.
Brain Neoplasms ; Central Nervous System Neoplasms ; Central Nervous System ; Cytogenetics ; Diagnosis ; Frozen Sections ; Humans ; Meningeal Neoplasms ; Methods ; Neurilemmoma ; Pituitary Neoplasms ; Retrospective Studies

Schwannoma is a slow-growing, well-demarcated, benign soft tissue tumor of the peripheral nerve sheath. It commonly develops in the head and neck region, usually in the parapharyngeal space. In this case, a 42-year-old woman visited the outpatient department to manage a painless mass on her left cheek. She had no history of concern and no neurological symptoms were observed. In the enhanced computed tomography scan, a 2.8 × 2.8 × 1.8 cm, heterogeneously enhanced tumor was detected in the left masseter muscle. A tumor resection under general anesthesia was planned. For the resection, a facelift incision was chosen; branches of the facial nerve were identified and retrogradely dissected. A well-marginated, yellowish, solid mass was found in the left masseter muscle. The mass was excised and given a histopathological diagnosis of schwannoma. A definite diagnosis of schwannoma, originating in the masseter muscle, is difficult to arrive at with radiographic findings alone; it is often misdiagnosed as intramuscular hemangioma. Histopathological examinations, including fine-needle aspiration or histological biopsy after surgery, are necessary. Using a facelift incision with retrograde facial nerve dissection, tumor resection in an intramasseteric lesion can be performed efficiently, without nerve damage, or leaving conspicuous scars on the face.
Adult ; Anesthesia, General ; Biopsy ; Biopsy, Fine-Needle ; Cheek ; Cicatrix ; Diagnosis ; Facial Nerve ; Female ; Head ; Hemangioma ; Humans ; Masseter Muscle ; Neck ; Neurilemmoma ; Outpatients ; Peripheral Nerves ; Rhytidoplasty

Schwannoma or neurilemmoma is a benign peripheral nerve sheath tumor that arises from Schwann cells. Approximately 25–45% of all schwannomas occur in the head and neck regions, and the intraoral presentation of these is only 1%. We report a rare case of a patient presenting tongue base schwannoma with characteristic imaging features on computed tomography and magnetic resonance imaging.
Diagnosis, Differential ; Head ; Humans ; Magnetic Resonance Imaging ; Neck ; Nerve Sheath Neoplasms ; Neurilemmoma ; Peripheral Nerves ; Schwann Cells ; Tongue

Gastric schwannoma, a rare mesenchymal tumor originating from the schwann cells of peripheral nerves, rarely occurs in the gastrointestinal tract. It accounts for only 0.2% of all gastric tumors and 2~6% of gastric mesenchymal tumors. Gastric schwannoma is observed as a subepithelial tumor on endoscopy; it is covered with normal mucosa, rendering its preoperative differential diagnosis difficult. An asymptomatic 43-year-old woman visited our hospital after a 7-cm ulcerofungating mass was detected in the lesser curvature of the gastric body on gastroscopy. Abdominal CT revealed multiple enlarged lymph nodes, and ¹⁸F-fluorodeoxyglucose (FDG) PET demonstrated a subtle uptake of FDG, suggestive of advanced gastric cancer. After three failed attempts of endoscopic biopsy, the patient underwent total gastrectomy with lymphadenectomy and was subsequently diagnosed with gastric schwannoma. Herein, we report this case with a literature review.
Adult ; Biopsy ; Diagnosis, Differential ; Endoscopy ; Female ; Gastrectomy ; Gastrointestinal Tract ; Gastroscopy ; Humans ; Lymph Node Excision ; Lymph Nodes ; Mucous Membrane ; Neurilemmoma ; Peripheral Nerves ; Schwann Cells ; Stomach Neoplasms ; Tomography, X-Ray Computed

A schwannoma is a benign tumor that develops from Schwann cells. It is known to occur more frequently in women than men, and about one third of schwannoma cases occur in the head and neck area. It is also known to originate mainly in the auditory nerve. However, it is rarely associated with the trigeminal nerve, and especially, schwannomas related to the infraorbital nerve are very rare. we report a rare case of a schwannoma involving the infraorbital branch of the trigeminal nerve in a 45-year old male adult. The patient underwent physical examination and magnetic resonance imaging. The mass was approached through subciliary approach that is familiar to the plastic surgeon and completely resected. Histopathological findings showed pointed to a benign schwannoma. Infraorbital nerve schwannoma is difficult to distinguish from other diseases by means of clinical symptoms, physical findings, or imaging. In spite of its rarity, infraorbital nerve schwannoma may be considered a possible diagnosis in the case of mass on cheek. Assessment by computed tomography or magnetic resonance imaging is necessary for proper diagnosis. About the surgical approach, excision through the subciliary approach should be considered rather than the direct transfacial approach in view of stability, cosmetic effects, and familiarity.
Adult ; Cheek ; Cochlear Nerve ; Diagnosis ; Female ; Head ; Humans ; Magnetic Resonance Imaging ; Male ; Neck ; Neurilemmoma* ; Physical Examination ; Plastics ; Recognition (Psychology) ; Schwann Cells ; Trigeminal Nerve

A primary benign schwannoma of the liver is extremely rare. Only 30 cases have been reported in the medical literature worldwide, and only one case has been reported in Korea previously. A 56-year-old man was admitted to Gil Medical Center with incidental findings of a hepatic mass by abdominal computed tomography. The computed tomography and magnetic resonance image revealed a 3×2 cm-sized solid mass in the left lobe of the liver. Histological examination confirmed the diagnosis of a benign schwannoma, proven by positive immunoreaction with the neurogenic marker S-100 protein and a negative response to CD34, CD117, and smooth muscle actin. We report a primary benign schwannoma of the liver and review the literature.
Actins ; Diagnosis ; Humans ; Incidental Findings ; Korea ; Liver ; Middle Aged ; Muscle, Smooth ; Neurilemmoma* ; Peripheral Nervous System Neoplasms ; S100 Proteins

Schwannomas are uncommon neoplasms that arise from Schwann cells of the neural sheath. Gastrointestinal schwannomas are rare among mesenchymal tumors of the gastrointestinal tract, and only a few cases have been reported to date. Duodenal schwannomas are usually discovered incidentally and achieving a preoperative diagnosis is difficult. Schwannomas can be distinguished from other subepithelial tumors on endoscopic ultrasonography; however, any typical endosonographic features of duodenal schwannomas have not been reported due to the rarity of these tumors. Immunohistochemistry is essential to distinguish schwannomas from gastrointestinal stromal tumors and leiomyomas. We report a case of duodenal schwannoma found incidentally during a health check-up endoscopy. On endoscopic ultrasonography, this tumor was suspected as a gastrointestinal stromal tumor; therefore, the patient underwent laparoscopic wedge resection of the tumor. Histopathology and immunohistochemistry confirmed that the duodenal lesion was a benign schwannoma.
Diagnosis ; Duodenum ; Endoscopy ; Endosonography ; Gastrointestinal Stromal Tumors ; Gastrointestinal Tract ; Humans ; Immunohistochemistry ; Leiomyoma ; Neurilemmoma* ; Schwann Cells

Peripheral neurogenic tumors can be featured by entering-and-exiting-nerve sign,which,however,is rarely seen in patients with spinal schwannoma. In this article we report a spinal schwannoma case with entering-and-exiting-nerve sign.
Humans ; Neurilemmoma ; diagnosis ; Peripheral Nervous System Neoplasms ; diagnosis