• Korean Journal of Head & Neck Oncology
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• v.28 no.2
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• pp.149-152
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• 2012

Paraganglioma of the thyroid is a neuroendocrine tumor originating from the neural crest. To our knowledge, only 32 cases of thyroid paraganglioma(TP) have been reported to date. TP is difficult to distinguish from medullary thyroid cancer(MTC), hence correct diagnosis is seldom obtained preoperatively. Although immunohistochemistry is helpful for confirmation of TP, these markers are not specific for differential diagnosis between TP and MTC. Therefore, an index of suspicion is important when encountered with MTC with unusual features, or given pathology with neuroendocrine features and unusual immunohistochemical findings. The authors report a case of TP misdiagnosed as MTC at preoperative work-up and intraoperative frozen section analysis, with a review of the literature. The case depicts various immunohistochemical characteristics of the tumor.

• Clinics in Shoulder and Elbow
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• v.11 no.2
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• pp.193-195
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• 2008

Authors report a case of cystic tuberculosis of left olecranon in a 44 year-old woman, which mimicked the bone tumor at initial presentation. She complained mild discomfort in the left elbow over a month. On examination there were no local redness, swelling, tenderness and deformity. There was no limitation of left elbow motion. After open curettage of the lesion, bone tuberculosis was confirmed by histological study. Postoperative triple chemotherapy of 12 months (Rifamcpicin, ethambutal, INH) could cure the disease.

• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1514-1518
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• 2000

Aspergillosis is an uncommon form of fungal infection of the central nervous system in immunocompetent patient, especially those involving the pituitary gland. Several cases of pituitary aspergillosis have been reported, but most of them are directly invaded from aspergillosis of sphenoid sinus. In the present case, a woman with primary pituitary aspergillosis had neither evidence of infection of the sphenoid sinus nor immunodeficiency. The patient underwent a transsphenoidal surgery for a presumed pituitary tumor. Histopathology demonstrated typical findings of aspergillosis. Postoperatively, amphotericin-B was administered and Gallium-67 scan was performed. We describe a case of primary pituitary aspergillosis mimicking pituitary tumor.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.4
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• pp.199-203
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• 2014

Clear cell odontogenic carcinoma (CCOC) is a rare jaw tumor that was classified as a malignant tumor of odontogenic origin in 2005 by the World Health Organization because of its aggressive and destructive growth capacity and metastasis to the lungs and lymph nodes. We report a case of a 66-year-old female who had swelling, incision and drainage history and a well-defined unicystic radiolucent lesion that was comparable to a cystic lesion. At first, the patient received decompression, and the lesion size decreased. Three months after decompression, cyst enucleation was performed. The pathologic result indicated that the lesion was CCOC. In this report we emphasize that patients with painful cystic lesions in addition to jaw enlargement and loosening teeth should be considered for the possibility of malignancy.

• Journal of Chest Surgery
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• v.48 no.4
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• pp.294-297
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• 2015

Epithelioid hemangioendothelioma (EHE) is a relatively rare and moderately aggressive type of vascular tumor. We describe a case of EHE that presented in a 24-year-old woman as a palpable nodule in the left cervical area. Radiological examinations and fine-needle aspiration cytology led to a preliminary diagnosis of metastatic lymphadenopathy with an unknown primary site. However, during surgery, we determined that the nodule was an intra-vascular tumor arising from the left internal jugular vein. The histopathological examination revealed cords of epithelioid endothelial cells distributed in a hyaline stroma, compatible with a diagnosis of EHE.

• Korean Journal of Head & Neck Oncology
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• v.34 no.1
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• pp.41-43
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• 2018

The Spindle cell lipoma is a slow-growing benign tumor seen generally in the shoulders, upper back, and back of the neck of male. The Pleomorphic (giant-cell) lipoma is a benign tumor of adipose tissue with atypical histological features. It is mainly seen in the same lesion as the Spindle cell lipoma. The Pleomorphic lipoma is cytogenetically similar to spindle cell lipoma with a consistent loss of chromosome 16q material. For this reason, these two entities are regarded as a similar spectrum in the adipose tumors. Herein, we present a 53-year old man with Spindle cell/pleomorphic lipoma in the lateral neck. Physical and radiologic examinations of the Spindle cell/pleomorphic lipoma in the lateral neck are not specific and preoperative diagnosis is usually difficult. Therefore, clinicians should consider the possibility that Spindle cell/pleomorphic lipoma may occur in the lateral neck mimicking the other more frequently observed lesions.

• Molecules and Cells
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• v.20 no.2
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• pp.196-200
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• 2005

The neurofibromatosis type2 (NF2) tumor suppressor gene product, merlin, is structurally related to the ezrin-radixin-moesin (ERM) family of proteins that anchor the actin cytoskeleton to specific membrane proteins and participate in cell signaling. However, the basis of the tumor suppressing activity of merlin is not well understood. Previously, we identified a role of merlin as an inhibitor of the Ras-ERK signaling pathway. Recent studies have suggested that phosphorylation of merlin, as of other ERM proteins, may regulate its function. To determine whether phosphorylation of merlin affects its suppression of Ras-ERK signaling, we generated plasmids expressing full-length merlin with substitutions of serine 518, a potential phosphorylation site. A substitution that mimics constitutive phosphorylation (S518D) abrogated the ability of merlin to suppress effects of the Ras-ERK signaling pathway such as Ras-induced SRE transactivation, Elk-mediated SRE transactivation, Ras-induced ERK phosphorylation and Ras-induced focus formation. On the other hand, an S518A mutant, which mimics nonphosphorylated merlin, acted like wild type merlin. These observations show that mimicking merlin phosphorylation impairs not only growth suppression by merlin but also its inhibitory action on the Ras-ERK signaling pathway.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.62-66
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• 2016

Tumor suppressor protein p53 loses its function upon binding with the HDM2 protein, and inhibiting the p53-HDM2 interaction is critical to suppress tumor cell growth. Recently, the cyclized helix-loop-helix peptide (cHLH) mimicking the ${\alpha}-helix$ part of the p53 protein has been designed and found to exhibit high binding affinity with HDM2. Here, we report the structural and thermodynamic characteristics of the bound complex of the cHLH peptide with the HDM2 protein. We performed molecular dynamics simulations to investigate the structural features of the cHLH peptide as well as its complex with the HDM2. The binding free energy calculation based on the integral equation theory was also executed to quantify the binding affinity for the cHLH/HDM2 complex and to understand the factors contributing to the binding affinity. We found a variety of factors for the helix stability of the cHLH peptide as well as in the complexation with the HDM2, which may provide an insight into the development of anti-cancer drug designs.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.61 no.11
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• pp.615-618
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• 2018

The central giant cell granuloma is a benign tumor seen generally in the mandible, but rarely in other cranial bones. Herein, we present a 51-year-old man with central giant cell granuloma in the right zygomatic bone. Physical and radiologic examinations of the central giant cell granuloma in the zygomatic bone showed that specific and preoperative diagnosis is usually difficult. Therefore, clinicians should consider the possibility that central giant cell granuloma may occur in the zygomatic bone mimicking other more frequently observed lesions.

• Investigative Magnetic Resonance Imaging
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• v.26 no.1
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• pp.60-65
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• 2022

Gadoxetic acid-enhanced magnetic resonance imaging (MRI) has been widely used to detect and characterize focal hepatic lesions. Because gadoxetic acid is a hepatocyte-specific contrast agent, its patterns during hepatobiliary phase enhancement provide useful information for differential diagnoses of focal hepatic lesions. Hepatic angiomyolipoma (AML) is a rare mesenchymal hepatic neoplasm composed of blood vessels, epithelioid cells, and varying amounts of adipose tissue components. Hepatic AMLs usually show marked hypointensity during the hepatobiliary phase of gadoxetic acid-enhanced MRI as hepatic AMLs are devoid of hepatocytes and fibrotic components. The present study describes a patient with hepatic AML and an atypical imaging feature. This tumor showed hyperintensity during the hepatobiliary phase of gadoxetic acid-enhanced MRI, mimicking hepatocellular tumors such as hepatocellular adenoma. The hepatobiliary hyperintensity of this lesion was likely due to multifocal entrapped hepatocytes resulting from an intrasinusoidal growth pattern of tumor cells and insufficient hepatic parenchymal enhancement during the hepatobiliary phase of gadoxetic acid-enhanced MRI.