Showing papers by "Seung Sam Paik published in 2007"

Reduced expression of Apaf-1 in colorectal adenocarcinoma correlates with tumor progression and aggressive phenotype.

Abstract: Apoptotic protease activating factor-1 (Apaf-1) is one of the key regulators in the mitochondrial apoptotic pathway, and the loss of Apaf-1 leads to cellular resistance against the apoptotic signals. We investigated the expression of Apaf-1 in colorectal tissues corresponding to the multistep carcinogenesis model to determine correlations between the clinicopathologic characteristics and the expression of this molecule and to evaluate the role of Apaf-1 in the development and progression of colorectal adenocarcinoma. Immunohistochemistry for Apaf-1 was performed on the tissue microarray of 38 normal mucosal tissues, 46 adenomatous polyps, 529 colorectal adenocarcinomas, and 76 metastatic tumors. Normal colonic mucosa tissues and adenomas were positive for Apaf-1 with no exceptions (100%). However, in colorectal adenocarcinomas, 119 of 529 cases (22.5%) were positive and 410 cases (77.5%) were negative. Moreover, 67 of 76 metastatic cases (88.2 %) were negative and only nine cases (11.8%) were positive for Apaf-1 expression. In the analyses between Apaf-1 expression and clinicopathologic parameters, reduced expression of Apaf-1 correlated with left colon location (p < 0.001), deeper tumor invasion (p < 0.001), frequent lymph node metastasis ( p= 0.021), higher American Joint Committee on Cancer (AJCC) and Dukes’ stage (p = 0.02 and p = 0.001, respectively) and poorer differentiation (p < 0.001). The patient survival was significantly associated with age, histological grade, AJCC stage, and lymphovascular invasion, but not Apaf-1 expression (p = 0.478). The results suggest that the loss of Apaf-1 expression is a relatively frequent late event and the loss of Apaf-1 expression may play an important role in tumorigenesis and tumor progression in colorectal adenocarcinoma.

Primary Synovial Sarcoma of the Thyroid Gland

Abstract: Synovial sarcoma is a rare but distinct soft tissue neoplasm, most commonly occurring in para-articular regions of the extremities of young adults and also occurring in the head and neck region. To the best of our knowledge, only one case of primary synovial sarcoma of the thyroid has been previously reported. Here, we report a 15-yr-old man who had a chief complaint of a palpable neck mass. The neck computed tomography revealed a relatively well-demarcated solid mass in the left thyroid gland. After fine needle aspiration cytology, total thyroidectomy and lymph node dissection were performed. Grossly, the mass was covered by the same capsule as the thyroid gland, measuring 6×5×5 cm in dimensions and weighing 78 gm. The cut surface showed a well demarcated, lobulated, grayish tan, and rubbery solid tumor. Histologically, this tumor was a biphasic synovial sarcoma. Immunohistochemical, ultrastructural, genetic studies, and cytologic findings were all consistent with synovial sarcoma. When synovial sarcomas arise in this unusual site, recognition and differential diagnosis become more difficult. The differential diagnosis of a spindle epithelial tumor with thymus-like differentiation is very difficult due to their similar clinical, histological, and immunohistochemical features. Ultrastructural and cytogenetic studies for synovial sarcoma are necessary to establish a definitive diagnosis.

An unusual case of bronchogenic cyst mimicking thyroid cystic tumor.

Abstract: Bronchogenic cysts are rare congenital anomalies of the ventral foregut and are related to abnormal budding of the tracheobronchial tree during embryological development. The majority of these occur in the mediastinum or within the pulmonary parenchyma and rarely in the neck. Those existing in the cervical region, especially in the thyroid or perithyroid area, are quite rare. To the best of our knowledge, there are only few other cases cited in the English-language literature. We herein describe a rare case of bronchogenic cyst that mimicks a thyroid tumor. A 40-year-old woman was admitted to our hospital for further evaluation of thyroid mass incidentally diagnosed at a local clinic. She had a history of dysphagia for three months. Results of routine laboratory tests including complete blood cell count, electrolytes, and urine analysis were within normal limits. There was no evidence of endocrine or metabolic abnormalities. A simple chest x-ray showed an increased soft tissue density in the left upper paratracheal area. A cervical computed tomogram (CT) showed a homogeneous cystic mass that measured 5 4 cm in cross diameters in the lower pole of the left thyroid gland (Fig 1). The left thyroid gland and trachea were deviated to the right side. Cervical lymph nodes were not enlarged. A preoperative fine needle aspiration cytology was performed, but the cytology was not diagnostic. The exact nature of the mass was questionable, and because a tumor in the left thyroid gland could not be ruled out, thyroid resection was scheduled. The patient underwent surgical exploration of the neck. The cystic mass showed fibrous adhesion to the lower pole of the left thyroid gland. A resection of the left lobe of the thyroid gland with the cystic mass was performed. Grossly, the mass presented a tan, smooth, and glistening outer surface, and the unilocular cyst contained thick brownish mucoid material. Microscopically, the cyst revealed only a lining of pseudostratified ciliated columnar epithelium. The stratified squamous epithelium was not noted. The cyst wall showed fibrous connective

Multilocular Thymic Cyst Associated with Mediastinal Teratoma: A Case Report

Abstract: Multilocular thymic cyst (MTC) has been reported to develop in concert with various mediastinal neoplasms that have intrinsic inflammatory components, such as thymoma, thymic carcinoma, Hodgkin’s disease, and seminoma. However, development of mediastinal teratoma without intrinsic inflammation in association with MTC has rarely been reported. Here, we report the findings of a case of MTC associated with mediastinal mature cystic teratoma on computed tomography (CT) with CThistopathologic correlation.