• The Korean Journal of Cytopathology
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• v.1 no.2
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• pp.158-163
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• 1990

Ancient (degenerated) schwannomas are benign tumors that display pronounced degenerative changes including cyst formation, calcification, hemorrhage, and hyalinization. The tumors are usually infiltrated by large numbers of inflammatory cells such as neutrophils, lymphocytes, siderophages, and histiocytes. They are located in deep locations such as the retroperitoneum and must be differentiated from malignant soft tissue tumors because spindle cells with nuclear atypia may be present. In the fine needle aspiration biopsy. The cytologic findings of two cases of ancient schwannoma occurring in posterior mediastinum and retroperitoneum, respectively, are described. Computerized tomographic findings of both cases showed changes of cystic degeneration or necrosis. A case occurred in retroperitoneum revealed features of destruction of vertebral body to suggest a malignant soft tussue tumor radiologically. The cytologic findings of aspiration biopsy of both tumors revealed that the tumor cells were spindle in shape with elongated nuclei. Some of tumor cells were arranged in a palisading fashion. Cell structures that resemble the Verocay bodies were observed. Some of the tumor cells showed pleomorphic bizarre nuclei, but no mitotic activity or chromatin clumping was seen. Inflammatory cells, siderophages and histiocytes were scattered in fibrillar material. These cytologic findings are important in the diagnosis of ancient schwannoma and in the differentiation of this tumor from the malignant spindle cell tumor.

• Clinical Endoscopy
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• v.51 no.6
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• pp.587-590
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• 2018

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 checkup 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.

• Journal of Oral Medicine and Pain
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• v.43 no.4
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• pp.147-151
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• 2018

Disuse atrophy involves gradual muscle weakening due to inadequate usage and can cause temporomandibular disorder (TMD). A 45-year old man with TMD symptoms on the left side, who had disuse atrophy of the masticatory muscles on the right side following surgical removal of a trigeminal schwannoma on the right side, first visited the Department of Orofacial Pain and Oral Medicine at Kyung Hee University Dental Hospital with left jaw pain and difficulty in opening mouth and chewing. He had been experiencing difficulties in cognitive function, decrease in visual acuity, impaired speech, and writing deficits after brain surgery. Furthermore, he complained of abnormal occlusion on the right side, which interfered with his ability to chew comfortably and open his mouth effectively. Herein, we describe a contralateral TMD case due to ipsilateral disuse atrophy after brain surgery for a trigeminal schwannoma and our successful treatment with medication, physical therapy, and stabilization splint.

• Archives of Craniofacial Surgery
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• v.21 no.6
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• pp.380-383
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• 2020

Schwannomas, which originate from Schwann cells in the peripheral nervous system, are slowg-rowing and uncommon benign tumors. Most schwannomas (90%) occur in isolation, and multiple occurrences are a characteristic feature of neurofibromas. Schwannomas of the nose and nasal tip are particularly unusual. Although a few cases of schwannomas of the sinusoidal tract and nasal septum have been reported, schwannomas arising from the nasal dorsum area and tip are extremely rare. Sensory abnormalities are also a very rare symptom. We excised a schwannoma on the nasal dorsum through direct incision and a schwannoma on the nasal tip through open rhinoplasty. No postoperative complications involving recurrence, hematoma, or infection occurred. The possibility of neurological changes should be considered in cases of an abnormality in the peripheral nervous system. Schwannoma must be kept in mind as a possible cause of neurological changes localized to a specific dermatome, and should always be considered in the differential diagnosis of a mass on the nose.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.4
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• pp.233-238
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• 2023

Schwannomas exhibit histopathological variation that leads to diagnostic dilemmas, although less frequent in the oral cavity. We describe a case with unique histopathology and no relevant clinical history that adds to the breadth of literature on the diversity presented by Schwannoma. A 60-year-old female patient presented with a small dome-shaped, asymptomatic swelling on the alveolar ridge 6 years in duration. Histopathologically, it showed rich cellular pathology with a unique arrangement of tumor cells forming irregular rosettes. Each rosette presented with a central core of fibrin-collagenous material and the tumor cells were arranged on the periphery, exhibiting epithelioid change with evidence of mild cellular and nuclear pleomorphism. On immunohistochemical evaluation, the cells were strongly and diffusely positive for S-100 and negative for Ki-67. A diagnosis of benign Schwannoma with a rosette-like arrangement with epithelioid change was made. The case report emphasizes the risk of misdiagnosis and the importance of awareness regarding rare histopathological variants of Schwannoma.

• Journal of the Korean Orthopaedic Association
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• v.54 no.1
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• pp.84-89
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• 2019

Schwannomas are benign neoplasms with a Schwann cell origin. A plexiform schwannoma is a rare variant of a schwannoma with a plexiform or multinodular growth pattern. The condition occurs mostly as a solitary lesion in the skin or subcutaneous tissue, or uncommonly located in the deep soft tissue. We report a rare case of recurred multiple plexiform schwannomas arising from the posterior tibial nerve and its branch, which was located in a deep anatomic location and accompanied by a bony deformity.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.6
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• pp.494-498
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• 2009

Schwannomas are tumors which originate from the neuroectodermal Schwann cell of cranial, intraspinal, peripheral and autonomic nerve sheaths, and they are solitary, benign, slow growing and well encapsulated neoplasm. Schwannomas are usually asymptomatic. No strong gender or age predominance exists. The incidence of extracranial schwannomas in the head and the neck region varies from 25~45%. In addition, schwannomas are rare in the maxillary sinus or buccal space. In this paper, it diagnosed and treated a 54-years old female patient, who had schwannoma in the maxillary sinus derived from infraorbital nerves, the branch of the left trigeminal nerve, and a 19-years old male patient, who had schwannoma arose in the buccal space derived from the buccal branch of the right facial nerve. There was no particular complication except sensory extinction of the nerve in the female patient and paralysis by the nerve in the male patient. It is determined those two cases of schwannoma in the rare portion is valuable and herein, it reports those with literature discussions.

• Investigative Magnetic Resonance Imaging
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• v.21 no.1
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• pp.38-42
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• 2017

Schwannomas are mostly solid tumors, some of which may contain cystic degenerations or hemorrhages. However, a schwannoma seen as a purely hemorrhagic cystic tumor is very rare. A 63-year-old woman was referred to the hospital due to a slow-growing mass (present for about 5 years) on her right thigh. She complained about vague pain but without neurologic symptoms such as numbness or tingling sensations. MR images showed an oval lesion with defined margins surrounded by the rectus femoris, vastus lateral, and the vastus intermedius. It was characterized as a multilocular cystic lesion composed of hemorrhagic fluid. In addition, the benign hemorrhagic cystic lesion was differentially diagnosed by radiological techniques as a hemorrhagic ganglion cyst. The lesion was surgically excised and, based on pathological features, was diagnosed as being a schwannoma. We report a purely hemorrhagic cystic schwannoma located in an intermuscular plane.

• Archives of Craniofacial Surgery
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• v.14 no.1
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• pp.61-64
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• 2013

Schwannomas are well-differentiated solitary benign tumors that originate from the schwann cells of the nerve sheath. They can readily occur in the head and neck regions, but the schwannoma originating from the infraorbital nerve is extremely rare and usually painless, slow-growing, and without specific symptoms. The author experienced a rare case of infraorbital schwannoma, which was completely removed through the intraoral approach. A 20-year-old woman was admitted to our hospital for a painless, solid and circular mass located on the right infraorbital region. The eyeball movement and visual field were normal. There was no globe displacement or proptosis. Preoperative computed tomography demonstrated $13{\times}10{\times}5mm$-sized soft tissue mass. On March 2011, the mass was removed through an intraoral approach. On histopathological examination, the gross specimen consisted of a smooth, well-encapsulated and light yellowish solid mass, measuring $12{\times}7{\times}5mm$. Microscopically, it presented a typical manifestation of schwannoma with Antoni A area with Verocay body, and Antoni B area on H&E stain. The result of the immunohistochemical staining was positive for the S-100 protein. The patient had hypoesthesia of the nasal septum and vestibule in the postoperative period, and this finding confirmed that the internal nasal branch of infraorbital nerve was the nerve in which the schwannoma originated. Infraorbital schwannomas are very rare and must be included in the differential diagnosis of the orbital masses inferior to the eyeball. In the case of early diagnosis, the small-sized infraorbital schwannomas can be completely removed without any scar through an intraoral approach.

• Archives of Reconstructive Microsurgery
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• v.21 no.2
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• pp.165-169
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• 2012

Intramuscular schwannomma is unusual and rare cases were reported in the literature in the gluteus maximus muscle. We present a case of an intramuscular schwannoma arising from the gluteus maximus muscle in a sixty-five-year-old woman. An oval in shape and well encapsulated tumor was found embedded with the gluteus maximus muscle, and then the lesion was excised surgically. Two years following excision of the lesion, the patient remained asymptomatic, with no evidence of local recurrence.