• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.104-112
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• 1998

Purpose : To evaluate the clinical utility of diffusion-weighted imaging by analyzing the signal intersity of lesions in patients with various intracranial diseases. Materials and Methods : difusion-weighted MR imaging was prospectively perormed in randomly selected 70 patients with various intracranial idseases. They consisted of 20 patients with acute infarct, 21 patients with chronic infarct of small vessel disease, 14 patients with primary intracranial tumor, three patients with brain metastasis, five patient with brain abscess, five patients with brain abscess, five patients with cerebral hemorrhage, one patient with neurocysticercosis, and one patient with epidermoid cyst. the diffusion-weighted images were obtained immediately after routine T2-weighted imaging on a 1.5T MR unit using single shot spin echo EPI technique with 6500 ms TR, 107ms TE, $128{\times}128$ matrix, 1 number of excitation, $24{\times}24$ field of view, 5-7 mm slice thickness, 2-3 mm inter-slice gap. The diffusion-gradients (b value of ($1000s{\;}/{\;}textrm{mm}^2$)) were applied along three directions(x, y, z). On visual inspection of diffusion-weighted images, the signal intersity of lesions was arbitrarily graded as one of 5 grades. In quantitative assessment, we measured the signal intensity of all the lesions and the contralateral corresponding normal area using round region of interest(ROI), and then calculated the signal intensity ratio of the lesion to the normal brain parenchyma. Results : On visual inspection, markedly hyperintense signals were seen in all cases of acute infarct, brain abscess, epidermoid cyst, and neurocysticercosis in degenerating stage. In all cases of cerebral hematoma, the very high signal internsity was intermingled with low signal intensity. focal very high signal intersity was also seen in a solid portion of the tumor in a patient. the mean signal intensity ratios of all those lesions to the normal brain parenchyma were above 2.5. Gliosis, solid component of brain tumor, brain metastasis, and vasogenic dedma appeared isointense to the normal brain parenchyma in 71%, 64%, 100%, and 67%, respectively ; the mean signal intensity ratios of those lesions to the normal brain parenchyma ranged 1.15 to 1.28 and there was no significant difference among these(p>0.1). Cystic cerebromalacia and necrotic or cystic portions in tumor were markedly or slightly hypointense, and the mean signal intensity ratios were 0.45 and 0.42, respectively. Conclusion : Very high signal intensity of acute infarct, brain abscess, epidermoid cyst, and cystic neurocysticercosis in degenerating stage on diffusion-weighted images may be helpful in differentiating from other diseases that are hypointense or isointense to the normal brain parenchyma. It may be especially useful differentiation of brain abscess from brain tumor with necrotic or cystic portion.

• Journal of Chest Surgery
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• v.31 no.1
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• pp.40-45
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• 1998

Recently, video-assisted thoracoscopic surgery for mediastinal lesions has been considered a new effective therapeutic method. From March, 1992 to April, 1997, 33 cases of video assisted thoracoscopic surgery for mediastinal lesions were performed. Gender distribution was 16 males and 17 females. Average age was 42 years old(ranged from 14 to 69). The locations of lesions were anterior mediastinum in 14 cases, middle mediastinum in 5 cases, posterior mediastinum in 11 cases, and superior mediastinum in 3 cases. These included 9 neurilemmomas, 5 benign cystic teratoma, 4 pericardial cysts, 2 ganglioneuroma, 2 thymus, 2 thymic cyst, 1 thymoma, 2 esophageal leiomyomas, 1 dermoid cyst, 1 lipoma, 1 malignant lymphoma, 1 bronchogenic cyst, 1 pericardial effusion, and 1 Boerhaave's disease with empyema. Working window was needed in 6 cases. We converted to open thoracotomy in 6 cases. Reasons of convertion to open thoracotomy were large sized mass(1), severe adhesion(3), and difficult location to approach(2). The average operation time was 116min($\pm$56 min). The average chest tube drainage time was 4.7days. The average hospital stay was 8.7 days. Operative complications were atelectasis(2), empyema with mediastinitis(1), recurrent laryngeal nerve palsy(1), and plenic nerve palsy(1). In conclusion, VATS for mediastinal lesions were performed with shorter operation time and hospital stay, and lesser complications and pain than those of conventional thoracotomy.

• Clinical and Experimental Pediatrics
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• v.49 no.9
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• pp.1000-1004
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• 2006

Atretic cephalocele is a degenerative form of encephalocele, which is detected as a cystic mass in the head, primarily in infants. Its presentation and prognosis vary and depend on various factors, including the nature of the tissues within the cyst, other concomitant anomalies, the site of development, and the presence or absence of an embryonic straight sinus. We here report 2 cases of atretic encephalocele, that were transferred to our hospital because round tumors, misdiagnosed as dermoid cysts, were detected in their parietal lobes immediately after birth. On diagnostic and differential MRI, an embryonic straight sinus was detected while histochemical results indicated that the lesions contained cerebral tissues. Despite these structural anomalies, the two patients developed normally neurologically and no other anomalies were detected. We here discuss these two cases and present a review of the relevant literature.

• Korean Journal of Head & Neck Oncology
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• v.36 no.1
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• pp.27-31
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• 2020

The midline nasal dermoid cysts are rare congenital neoplasms, which are diagnosed frequently in childhood. Masses are often noticeable at birth gaining size over time with recurrent infections and usually arise from the nasal cavity or lower 1/3 of the nasal dorsum. CT scan as the primary investigation is helpful to determine accurately the size and extent of the lesion as well as the integrity of adjacent bony structures. MRI scan is recommended to rule out an intracranial extension or sinus tracts. Treatment of choice is the complete surgical excision preserving the cyst wall. Here in, we present an unusual case of nasofrontal dermoid cyst in a 19-year-old boy without radiographic evidence of transcranial extension. In this case, we surgically removed nasofrontal dermoid cyst via transcolumellar approach. We also corrected saddle nose deformity after mass removal. Therefore, in this case, we experienced a successful case in which the nasofrontal dermoid cyst was totally removed without facial scar and deformity.

• Archives of Plastic Surgery
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• v.34 no.4
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• pp.508-511
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• 2007

Purpose: Dermoid cysts are almost always caused by congenital events. The most widely accepted pathogenesis is that the cysts are dysembryogenetic lesions that arise from ectodermic elements entrapped during the midline fusion. We report a rare case of dermoid cyst, which occurred not congenitally but newly in the subcutaneous scar tissue secondary to trauma. Methods: A 26-year-old man had a deep submental laceration caused by a car accident and got a primary wound closure 16 months ago. There were 18 cm-long submental hypertrophic scar and newly developed palpable masses inside the subcutaneous layer at the center of the scar. Initial impression was an epidermal cyst or a thyroglossal duct cyst. Ultrasonographic finding showed two cystic masses inside the scars at the submental area, but impressed dermoid cysts. The cystic masses were completely removed with W-plasty and histological examination were followed. Results: The histological diagnosis was dermoid cysts which were mainly composed of keratotic squamous epithelium in their inner surface linings and numerous skin appendages such as sebaceous glands, sweat glands, and hair follicles in their cystic lumens histopathologically. During the follow-up period of 25 months, there was no recurrence of any subcutaneous mass in the site of scar. Conclusion: We report a very unusual case of dermoid cysts developed by an acquired cause, considering that the accidental inclusion of deep skin elements caused by a trauma can be a critical origin of dermoid cysts.

• Investigative Magnetic Resonance Imaging
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• v.18 no.2
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• pp.144-150
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• 2014

Purpose : Intramedullary spinal lesions in the conus medullaris (CM), including tumors and vascular lesion, are rarely reported. We reported various MR features of intramedullary spinal cord lesions involving the CM including ependymoma, hemangioblastomas, dermoid cyst, ventriculus terminalis and spinal AVF and tried to discuss them for differential diagnosis. Materials and Methods: Six patients (male: female = 4:2, mean age = 44.3 year old) were enrolled from the clinical database of our institute from 2004 to 2010 and their radiological images and clinical symptoms were reviewed retrospectively. All patients had taken initial and postoperative MRI with contrast enhancement using gadopentate dimeglumine (Gd-DTPA). These images were analyzed by tumor size, location, signal intensity relative to the spinal cord, vascular flow voids, syrinx or cyst, edema and enhancement pattern. Results: Contrast enhancement was seen in all intramedullary masses. An eccentric enhancing nodule was noted in two hemangioblastomas and unusual peripheral rim enhancement with septation was seen in ventriculus terminalis. Patchy enhancement of the CM was observed in spinal arteriovenous fistula (AVF). Extensive cord edema adjacent to the intramedullary lesions was seen in four cases and syrinx was noted in three cases. Vascular signal voids were found in two hemangioblastomas and one spinal AVF. Conclusion: In evaluation of intramedullary spinal lesions in the CM, it is necessary to consider these unusual MR findings and discriminate various pathologies with prudence and caution.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.481-484
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• 2010

Purpose: Congenital dermoid cysts develop during the fusion of the embryo when the ectodermal tissue gets trapped in the line of fusion. Dermoid cysts of the head are rare lesions comprised of epidermal and mesodermal elements. Furthermore, dermoid cysts in the occipital area are extremely rare. Only a few cases of dermoid cysts in the posterior scalp have been reported. Especially, A bilateral, synchronous presentation in this location has not been reported previously in the literature. Methods: All 5 cases had a gradually enlarging mass of the posterior aspect of the scalp. The cysts were mobile, noncompressible, and non-tender, without evidence of an associated sinus tract, skin dimpling, discoloration, or communication with adjacent structures. The CT scan displayed a hypodense cystic lesions about -87 to +24 HU (Housefield units, average +3.2 HU) with hypodense capsule and no postcontrast enhancement. All tumors were found just under the skin, and were well encapsulated, so they were completely removed the mass with adjacent periosteum. Results: On gross findings, all tumors were oval-or round-shaped, and when the cystic tumor was cut open it presented a greasy and caseous substance. Histologically, all specimens contain desquamated squamous epithelium and keratin in the lumen and are encapsulated and lined by keratinized stratified squamous epithelium. And, all cases of posterior mass are the presence of adnexal structures. Conclusion: Appropriate diagnosis requires not only an index of suspicion for this rare tumor a very careful history and search for skin changes. Especially, CT can reveal the exact location of the cyst, its relationship with the adjacent structures. We think that occipital dermoids divide into superficial and deep type. In our cases, because they did not have intra-cranial involvement or fistula formation, they are superficial type. This report describes the clinical and operative aspects of the superficial dermoid cysts and provides a review of the literatures.