• Korean Journal of Bronchoesophagology
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• v.18 no.1
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• pp.24-26
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• 2012

As benign tumor originating in Schwann cells of nerve sheath, Schwannoma can rise in any site involving cranial nerve, sympathetic nerves, peripheral nerves excepting optic nerves and olfactory nerves. Schwannoma rarely occurs in trachea, and although can appear in any part, most often seen in the lower third of the trachea. Here, we reported a case of intra-tracheal schwannoma misdiagnosed and treated as bronchial asthma, later identified and successfully excised through an external approach.

• Journal of Korean Foot and Ankle Society
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• v.18 no.1
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• pp.36-39
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• 2014

Tarsal tunnel syndrome is defined as a compressive neuropathy of the posterior tibial nerve in the tarsal canal. Schwannoma is a benign tumor that arises from the peripheral nerve sheath. It presents as a discrete, often tender, and palpable nodule associated with neurogenic pain or paresthesia when compressed or traumatized. The growth rate is usually slow, and these lesions seldom exceed 2 cm in diameter. In addition, local recurrence occurs less than 5%. We report on a case of tarsal tunnel syndrome caused by a large recurred space-occupying lesion measuring $4.3{\times}2.7{\times}2.7cm^3$.

• Archives of Craniofacial Surgery
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• v.20 no.6
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• pp.388-391
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• 2019

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.

• Korean Journal of Bronchoesophagology
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• v.14 no.2
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• pp.48-52
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• 2008

Ectopic Hamartomatous thymoma(EHT) is a rare benign tumor that occurs mainly in the supraclavicular or suprasternal area. Since this entity was first reported by Smith et al. in 1982, less than 50 cases have been reported in the literature. Recognition of EHT is important and needs to be differentiated from high-grade sarcomas such as synovial sarcoma or malignant peripheral nerve sheath tumor because EHT follows a benign clinical course. We experienced a case of ectopic hamartomatous thymoma in the suprasternal area in a 53-year-old man. Here, we present the case with a review of the related literatures.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.498-500
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• 2011

Purpose: Neurilemoma is benign tumor of the nerve sheath which arises from Schwann cells. It is usually formed along the path of a peripheral nerve but is rarely separate from normal nerve fascicles. We experienced a patient with an isolated neurilemoma localized in the palmaris longus tendon with no connection to the major nerve trunk, which was in an unusual location and has never been reported. We report our case with the review of the literature. Methods: A 23-year-old female visited our clinic with mild pain on the mass at the flexor area of the right wrist which had been present for about one year. The physical examination revealed a $1{\times}1cm$ sized subcutaneous mass at the flexor area of the right wrist. Sonography and computed tomography showed an ovoid, superficial solid mass on the palmaris longus tendon. Upon surgical excision, a $1{\times}0.5cm$ sized mass attached to the palmaris longus tendon was found. The tumor had no connection with the median nerve and was detached easily from the palmaris longus tendon. Results: Histological examination demonstrated the mass to be a neurilemoma, which consists of spindle shaped cells with oval elongated nuclei arranged fascicles. No sensory dysfunction or evidence of recurrence was found during the 12 months of postoperative follow-up. Conclusion: We experienced a rare case of neurilemoma attached to the palmaris longus tendon with no connection to the major nerve trunk. We wish to emphasize its unusual location through our case and hope to expand our spectrum in exploring the upper extremity mass.

• Korean Journal of Veterinary Service
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• v.41 no.1
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• pp.57-61
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• 2018

Canine peripheral nerve sheath tumors (PNSTs) are spindle cell tumors that arise from Schwann cells, perineural cells, fibroblasts or all of them. Based on the morphology and biologic behavior, PNSTs are divided into benign PNST (BPNST) and malignant PNST (MPNST) forms. The aim of this study is to diagnose the two cases of neoplastic tissue samples with features of PNSTs by the histopathology and immunohistochemistry. The study was performed using two specimens from small animal clinic. The first case, A was a mass, 3~4 cm in diameter, extruded from vaginal mucosa of 10-year-old spayed female mixed-breed dog. And the second case, B was a subcutaneous mass, 1.5 cm in diameter, which is originated from right hind leg of 9-year-old castrated male mixed-breed dog. Two cases were stained with hematoxylin and eosin (H&E) for histopathological examination. And also immunohistochemistry (IHC) was performed by the avidin-biotin peroxidase complex (ABC) method with antibodies specific for the following proteins: S-100 protein, smooth muscle actin (SMA) and epidermal growth factor receptor (EGFR). In results, Antoni B schwannoma pattern characterized by pleomorphic, round and fusiform polygonal cells was seen in A. In B, Antoni A pattern, densely packed spindle cells arranged in interlacing bundles was seen in addition to Antoni B pattern. In IHC, cytoplasms of neoplastic cells were diffusely labeled for S-100 expression in A and B. For SMA, both A and B show negative expression. And for EGFR, A shows negative expression but B shows partially positive expression in areas of Antoni B schwannoma pattern. The histopathologic features of two cases coupled with the S-100 immunoreactivity led to a diagnosis of PNST. For SMA, both A and B show negative expression. The diagnosis of A will be a BPNST with the negative result and B will be a MPNST with the positive result for EGFR.

• Imaging Science in Dentistry
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• v.34 no.4
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• pp.215-218
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• 2004

Neurilemmoma is a benign tumor of the nerve sheath that arises on cranial and spinal nerve roots as well as along the course of peripheral nerves. A case of a neurilemmoma that arose in the left infratemporal fossa of a 29-year-old male was presented. Plain radiographs, enhanced computed tomography scan, and magnetic resonance imaging demonstrated a large, well-circumscribed, heterogeneously enhanced mass with extension into the pterygopalatine fossa. Displaced by the large mass, bowing-in of the posterior maxillary antral wall was noted and a provisional diagnosis of a benign soft tissue tumor was made. The mass was completely excised and a diagnosis of neurilemmoma was confirmed.

• The Journal of the Korean bone and joint tumor society
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• v.5 no.1
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• pp.44-50
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• 1999

Neurilemmoma is a benign encapsulated nerve sheath tumor originated from peripheral nerve. Previously its preoperative diagnosis had mainly depended on the history, physical examination, electrodiagnostic test, ultrasonography, bone scan. But only with these diagnostic modalities, exact preoperative diagnosis was nearly impossible. Therefore operation was performed under the impression of lipoma or just simple soft tissue tumor. Recently, the advent of magnetic resonance imaging(MRI) has made it easier to diagnose neurilemoma before surgery. MRI also helps to determine the extent of lesion and operative procedures. We performed marginal excision in 24 cases, evaluated those cases with respect to the sex, age, location, chief complaint, duration of illness, preoperative diagnosis, involved nerve, imaging studies, size of mass, complication, duration of follow-up and report with review of the literature.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.452-456
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• 2010

Purpose: The schwannoma is a benign peripheral nerve tumor arising from the Schwann cell of the nerve sheath. Only 2-8% of schwannomas arise in the hand and wrist. Misdiagnosis is frequent such as ganglion and neurofibroma. This article documents and clarifies the clinical features of schwannomas arising in the hand and wrist, and emphasizes importance of differential diagnosis and meticulous surgical extirpation under magnification. Methods: The author reviewed clinical features of 15 patients with pathologic final diagnosis of schwannoma developed in hand and wrist during the last 12 years from 1998 through 2009. The review included the sex, age of onset, duration, preoperative diagnosis, location, involved nerve, preoperative symptoms and. Postoperative sequelae after surgical extirpation of the lesion with magnification, or without magnification of the surgical fields. Results: The chief complaints were slow growing firm mass in all patients, and followed by pain in 40%, and paresthesia in 40% respectively. The lesions were developed solitarily in 14 patients (93%). The postoperative pathologic diagnosis and preoperative diagnosis were coincided with only in 6 patients (40%). Other preoperative diagnosis were soft tissue tumor in 4 patient (26.6%), and ganglion in 3 patients (20%), and neurofibroma in 2 patients (13%). In all patients who were undergone surgical excision under the fields of magnification, all symptoms were subsided without any sequelae. Meanwhile muscle weakness, paresthesia, hypoesthesia and /or accidental nerve resection developed after surgical excision with naked eye. Conclusion: Schwannoma in hand most commonly appears as a slow growing solitary mass with pain or paresthesia. The chance of preoperative misdiagnosis was 60% in this series. To provide good prognosis and less sequelae, careful and elaborate diagnostic efforts and meticulous surgical excision under the magnification are necessary in management of schwannoma.

• Korean Journal of Veterinary Service
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• v.34 no.4
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• pp.397-401
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• 2011

Aspiration of lytic bone lesions is an excellent diagnostic test in the initial evaluation of primary bone tumor. However, cytologically, it can be difficult to differentiate osteosarcoma (OSA) from other bone neoplasms, including fibrosarcoma, chondrosarcoma, synovial cell sarcoma, malignant fibrous histiocytoma and malignant peripheral nerve sheath tumor. The purpose of this study is to introduce alkaline phosphatase (ALP) staining to differentiate OSA from other mesenchymal tumors. Tumors actively producing bone are specifically positive for ALP staining. Unstained, cytologic specimens were incubated for 10 minutes with nitroblue tetrazolium chloride/5-bromo-4-chloro-3-indolyl phosphate toluidine salt-phosphatase substrate. Among 20 cases of cytology specimen, 14 were positive for ALP staining and histopathology, 6 were negative for ALP staining and histopathology. ALP staining was 100% sensitive and specificity for the diagnosis of OSA. Aspirate cytology with ALP staining was a simple, fast, safe and accurate diagnostic test for the evaluation of suspected OSA lesions in dogs.