• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.718-722
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• 1999

Thymoma is the most common tumor in the compartment of anterior mediastinum. The malignant thymoma is classified into invasive thymoma(category I) and thymic carcinoma(category II). Recently, well-differentiated thymic carcinoma is a proposed category 1.5 used to describe a subset of thymic epithelial tumors, allowing for the existence of intermediate form based on the clinical features and the histological characteristics. Thymic cyst is a congenital or a acquired disorder. Congenital thymic cyst may develop due to failure of the thymopharyngeal duct to obliterate and acquired thymic cyst develops from inflammation(multilocular thymic cyst), or neoplasm(cystic thymoma). Cystic degeneration in thymoma is a relatively frequent but focal event. In rare cases, the process proceeds to the extent that most or all of the lesion becomes cystic. Until now, well-differentiated thymic carcinoma with extensive cystic degeneration has not been reported in our country. We experienced a case of 14 year-old female patient showing extensive cystic degeneration in well-differentiated thymic carcinoma. And so we report it with review of the articles related.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.1_2
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• pp.160-168
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• 1992

Ameloblastoma is an aggressive but benign epithelial neoplasm of odontogenic origin, and the occurrence of odontogenic epithelium in the wall of a dentigerous cyst is well-known entity. The presence of ameloblastic proliferation in the walls of odontogenic cysts has been reported for many years. Cahn in 1933 described a case in which he considered an ameloblastoma to have originated in a dentigerous cyst, and numerous other cases of ameloblastomatous proliferation have since been reported. In 1977, Robinson and Martinez described a distinct variant of ameloblastoma in which the response to curettage was found to be favorable with a recurrence rate of 25%. The gross and microscopic features indicated that this variant vas associated with a large cystic cavity with either luminal or mural proliferation of ameloblastic tumor cells, and they referred to this variant as unicystic ameloblastoma. Unicystic ameloblastoma occurs most commonly in the second and third decades of life, which is considerably younger than the average age of discovery for the classical ameloblastoma. For the accurate histopathological diagnosis of the unicystic ameloblastoma, the specimen obtained the excisional biopsy, complete enucleation or incisional biopsy from the multiple site of the lesion. This article provides histopathologic evidence of multilocular unicystic ameloblastoma in which ameloblastic tissue was associated with a dentigerous cyst that was found in a 31-year-old female, and complete radiographic, photographic, and microscopic documentation is presented.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.27 no.1
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• pp.62-70
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• 2024

Purpose: Choledochal cysts are congenital anomalies that occur as localized cystic or fusiform dilatations of the biliary tree. Reflux and stasis of pancreatic enzymes in the biliary duct may relate to the development of intestinal metaplasia which might be an important factor related to the carcinogenesis of choledochal cyst, thus the expression of beta-catenin in the metaplastic epithelium might be associated with malignant transformation of choledochal cyst epithelium. Methods: This study was conducted at a tertiary care pediatric center between October 2014 and March 2017. Forty patients were evaluated for epithelial lining, mural ulceration, fibrosis, inflammation, and metaplasia. Results: Out of 40, 12 cases (30.0%) were the infantile age group and 28 cases (70.0%) were in the classic pediatric group. Ulceration was classified as grade 0 (14 cases, 35.0%), grade 1 (17 cases, 42.5%), or grade 2 (nine cases, 22.5%). Inflammation was classified as grade 0 (2 cases, 5.0%), grade 1 (26 cases, 65.0%), or grade 2 (12 cases, 30.0%). Fibrosis was classified as grade 0 (five cases, 12.5%), grade 1 (11 cases, 27.5%), grade 2 (17 cases, 42.5%), or grade 3 (seven cases, 17.5%). Metaplasia was noted in five (12.5%) out of 40 cases. All choledochal cysts with metaplasia showed beta-catenin nuclear positivity on immunohistochemistry and were followed up. Conclusion: This study emphasizes the importance of detailed histopathological examination and documentation of metaplastic changes. Metaplasia was associated with beta-catenin nuclear positivity. These findings suggest a potential role for beta-catenin as a marker of metaplastic changes in choledochal cysts.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.476-483
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• 2021

Traumatic bone cyst (TBC) is an asymptomatic lesion seen most in adolescents. TBC is found incidentally on routine panoramic examinations and appears as a relatively well-demarcated unilocular radiolucency with scalloped margins. Histological examination reveals a vacant cavity of cancellous bone usually unlined or very occasionally lined with a thin connective tissue layer. The lack of lining epithelial membrane is common histological feature. The most affected site is between the mandibular canine and third molar. The involvement of the mandibular symphysis is rare. The etiopathogenesis of the TBC is unclear. TBC is treated with surgical exploration and curettage; new bone is formed in place of the lesion within 6 - 12 months of surgery. Diagnosis of TBC prior to surgical intervention has limitations in most of the cases. Both of our patients were diagnosed through radiological examination and biopsy. Neither patient had a history of trauma. After surgery, the panoramic radiograph and CBCT were used to confirm bone healing.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.1
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• pp.15-21
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• 2000

Ameloblasotma is slowly growing, locally invasive neoplasm with a potentially destructive behavior. The epithelium of ameloblastoma is thought to have an intrinsic growth potential and has been shown to present a higher rate of proliferation as compared to odontogenic cysts with low local recurrence rate. The molecular mechanisms that regulate the cell growth and invasion of ameloblastoma cells are unknown. Bcl-2 protein, which prevent apoptosis, is expressed in immortalized ameloblastoma cell line(AM-1)(Harada et al 1998). Expression of bcl-2 protein occurs in tooth germs, whose epithelial component may act as the histogenic precursor of ameloblastoma. Bax is considered as a main effector of apoptosis. Bax forms homodimers and also heterodimers with bcl-2. p53 tumor supressor gene participates not only in cell proliferation control but also in induction of apoptosis. The objective of the present study was to evaluate the apoptosis related protein expression in odontogenic cyst and ameloblastoma. A total of 10 dentigerous cysts and 16 ameloblastomas were used in the present study. Dentigerous cyst showed negative or slight positive for p53 and bcl-2 but strongly positive for bax, ameloblastoma, on the other hand, strongly positive for p53 and bcl-2 but weekly positive for bax. Bcl-2 was expressed for ameloblastoma mainly in outer layer or whole layer of epithelium and for dentigerous cyst mainly in basal layer. The difference in expression of apoptosis related protein in dentigerous cyst and ameloblastoma might explain the peculiar aggressive growth pattern of ameloblastoma.

• BMB Reports
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• v.52 no.7
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• pp.463-468
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• 2019

Autosomal dominant polycystic kidney disease (ADPKD), one of the most common human monogenic diseases (frequency of 1/1000-1/400), is characterized by numerous fluid-filled renal cysts (RCs). Inactivation of the PKD1 or PKD2 gene by germline and somatic mutations is necessary for cyst formation in ADPKD. To mechanistically understand cyst formation and growth, we isolated RCs from Korean patients with ADPKD and immortalized them with human telomerase reverse transcriptase (hTERT). Three hTERT-immortalized RC cell lines were characterized as proximal epithelial cells with germline and somatic PKD1 mutations. Thus, we first established hTERT-immortalized proximal cyst cells with somatic PKD1 mutations. Through transcriptome sequencing and Gene Ontology (GO) analysis, we found that upregulated genes were related to cell division and that downregulated genes were related to cell differentiation. We wondered whether the upregulated gene for the chemokine CXCL12 is related to the mTOR signaling pathway in cyst growth in ADPKD. CXCL12 mRNA expression and secretion were increased in RC cell lines. We then examined CXCL12 levels in RC fluids from patients with ADPKD and found increased CXCL12 levels. The CXCL12 receptor CXC chemokine receptor 4 (CXCR4) was upregulated, and the mTOR signaling pathway, which is downstream of the CXCL12/CXCR4 axis, was activated in ADPKD kidney tissue. To confirm activation of the mTOR signaling pathway by CXCL12 via CXCR4, we treated the RC cell lines with recombinant CXCL12 and the CXCR4 antagonist AMD3100; CXCL12 induced the mTOR signaling pathway, but the CXCR4 antagonist AMD3100 blocked the mTOR signaling pathway. Taken together, these results suggest that enhanced CXCL12 in RC fluids activates the mTOR signaling pathway via CXCR4 in ADPKD cyst growth.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.2
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• pp.62-68
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• 1990

Intraosseous carcinoma of the jaw may arise as metastatic lesions most commonly from breast, lung, kindney and thyroid and also primarily occur from ameloblastoma or odontogenic cyst. Rarely primary intraosseous carcinoma could be originated from the epithelium involved in odontogenesis. According to WHO's classification, primary intraosseous carcinoma is defined as squamous cell carcinoma, occured in the Jaw without connection to the oral mucosa. However, Elzay defined primary intraosseous carcinoma as malignant epithelial tumor related to the odontogenic apparatus, including carcinoma ex-odontogenic cyst, carcinoma ex-ameloblastoma and carcinoma de novo. We experienced 2 cases of intraosseous carcinoma of the jaw. The first case, a 59-year-old man, showed a ill-defined mass on the left maxilla, measuring $8{\times}10cm$ in size. He received radical hemimaxillectomy and was diagnosed as ameloblastic carcinoma. The second case obtained from a 79-year-old woman showed a ill-defined $6{\times}8cm$ sized mass on the left mandibular body area. The mass was surgically removed by partial mandibulaectomy, which was diagnosed as the primary intraosseous carcinoma, probably odontogenic origin.

• Applied Microscopy
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• v.18 no.1
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• pp.49-59
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• 1988

Fine structures of the testis and vas deferens in the fall-web worm, Hyphantria cunea Drury, are studied with electron microscope. Adult worms have single testis close to the midlines of the abdomen. Testis is composed of 4 follicles which are incompletly separated from each other and bounded together by a peritoneal sheath. The peritoneal sheath consisted of outer cuticular layer and two kinds of inner layers, in which glycogen particles are dispersed commonly. These two layers are divided by the morphology of cytoplasmic granules. Follicular epithelium forming the wall of the follicles have melanin pigment granules, and trachea or tracheoles are extended through this epithelium. In the cysts of adult testis, matured spermatozoa are grouped together in bundles and after releasing the sperm bundles to the vas deferens, lamellar shaped lysosomes appeared in the cytoplasms of the cyst cells. The number of spermatozoa per cyst is exactly 256 ($2^8$), this number is characteristics of the Lepidoperan species. Vas deferens is a tube with a fairly thick bounding epithelium, a basement membrane and a layer of circular muscle outside it. At the apical portion of the epithelial cells, microvilli are well developed. And in the cytoplasms of these cells, numerous excretory granules are observed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.6
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• pp.589-592
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• 2008

Running title: A plunging ranula extended into parapharyngeal space Ranulas are lesion of sublingual gland origin, which occur in the floor of the mouth. Most ranulas, whether simple or plunging, are pseudocysts without and epithelial lining and ranulas have higher levels of salivary amylase and protein content. They can be classified into two types based on their extent: simple ranulas, confined to the sublingual space and plunging ranula which extend into adjacent spaces. Plunging ranula requires differential diagnosis with other lesions (neuroma, monomorphic adenoma, hemangioma, lipoma, dermoid cyst, lateral cervical cyst). The patient was diagnosed as plunging ranula. We experienced 17 years old male, visited to our department, who complain Rt. cervical swelling and in MRI view, this lesion involved sublingual, submadibular, parapharyngeal, skull base. We experienced a rare case of plunging ranula, extended into parapharyngeal space. We report the case.

• Korean Journal of Radiology
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• v.24 no.1
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• pp.62-78
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• 2023

As the majority of incidentally detected lesions in the anterior mediastinum is small nodules with soft tissue appearance, the differential diagnosis has typically included thymic neoplasm and prevascular lymph node, with benign cyst. Overestimation or misinterpretation of these lesions can lead to unnecessary surgery for ultimately benign conditions. Diagnosing mediastinal cysts using MRI serves as a problem-solving modality in distinguishing between surgical and nonsurgical anterior mediastinal lesions. The pitfalls of MRI evaluation for anterior mediastinal cystic lesions are as follows: first, we acknowledge the limitation of T2-weighted images for evaluating benign cystic lesions. Due to variable contents within benign cystic lesions, such as hemorrhage, T2 signal intensity may be variable. Second, owing to extensive necrosis and cystic changes, the T2 shine-through effect may be seen on diffusion-weighted images (DWI), and small solid portions might be missed on enhanced images. Therefore, both enhancement and DWI with apparent diffusion coefficient values should be considered. An algorithm will be suggested for the diagnostic evaluation of anterior mediastinal cystic lesions, and finally, a management strategy based on MRI features will be suggested.