Unsolved Questions on the Anatomy of the Ventricular Conduction System

We reviewed the anatomical characteristics of the conduction system in the ventricles of human and ungulate hearts and then raised some questions to be answered by clinical and anatomical studies in the future. The ventricular conduction system is a 3-dimensional structure as compared to the 2-dimensional character of the atrial conduction system. The proximal part consisting of the atrioventricular node, the bundle of His and fascicles are groups of conducting cells surrounded by fibrous connective tissue so as to insulate from the underlying myocardium. Their location and morphological characters are well established. The bundle of His is a cord like structure but the left and right fascicles are broad at the proximal and branching at the distal part. The more distal part of fascicles and Purkinje system are linear networks of conducting cells at the immediate subendocardium but the intra-mural network is detected at the inner half of the ventricular wall. The papillary muscle also harbors Purkinje system not in the deeper part. It is hard to recognize histologically in human hearts but conducting cells as well as Purkinje cells are easily recognized in ungulate hearts. Further observation on human and ungulate hearts with myocardial infarct, we could find preserved Purkinje system at the subendocardium in contrast to the damaged system at the deeper myocardium. Further studies are necessary on the anatomical characteristics of this peripheral conduction system so as to correlate the clinical data on hearts with ventricular arrhythmias.

Unsolved Questions on the Anatomy of the Ventricular Conduction System

We reviewed the anatomical characteristics of the conduction system in the ventricles of human and ungulate hearts and then raised some questions to be answered by clinical and anatomical studies in the future. The ventricular conduction system is a 3-dimensional structure as compared to the 2-dimensional character of the atrial conduction system. The proximal part consisting of the atrioventricular node, the bundle of His and fascicles are groups of conducting cells surrounded by fibrous connective tissue so as to insulate from the underlying myocardium. Their location and morphological characters are well established. The bundle of His is a cord like structure but the left and right fascicles are broad at the proximal and branching at the distal part. The more distal part of fascicles and Purkinje system are linear networks of conducting cells at the immediate subendocardium but the intra-mural network is detected at the inner half of the ventricular wall. The papillary muscle also harbors Purkinje system not in the deeper part. It is hard to recognize histologically in human hearts but conducting cells as well as Purkinje cells are easily recognized in ungulate hearts. Further observation on human and ungulate hearts with myocardial infarct, we could find preserved Purkinje system at the subendocardium in contrast to the damaged system at the deeper myocardium. Further studies are necessary on the anatomical characteristics of this peripheral conduction system so as to correlate the clinical data on hearts with ventricular arrhythmias.

Characteristics of Cutaneous Lymphomas in Korea According to the New WHO-EORTC Classification: Report of a Nationwide Study

BACKGROUND: Previously, cutaneous lymphomas were classified according to either the European Organization for the Research and Treatment of Cancer (EORTC) or the World Health Organization (WHO) classification paradigms. The aim of this study was to determine the relative frequency of Korean cutaneous lymphoma according to the new WHO-EORTC classification system. METHODS: A total of 517 patients were recruited during a recent 5 year-period (2006-2010) from 21 institutes and classified according to the WHO-EORTC criteria. RESULTS: The patients included 298 males and 219 females, and the mean age at diagnosis was 49 years. The lesions preferentially affected the trunk area (40.2%). The most frequent subtypes in order of decreasing prevalence were mycosis fungoides (22.2%), peripheral T-cell lymphoma (17.2%), CD30+ T-cell lymphoproliferative disorder (13.7%), and extranodal natural killer/T (NK/T) cell lymphoma, nasal type (12.0%). Diffuse large B-cell lymphoma accounted for 11.2% of cases, half of which were secondary cutaneous involvement; other types of B-cell lymphoma accounted for less than 1% of cases. CONCLUSIONS: In comparison with data from Western countries, this study revealed relatively lower rates of mycosis fungoides and B-cell lymphoma in Korean patients, as well as higher rates of subcutaneous panniculitis-like T-cell lymphoma and NK/T cell lymphoma.

Surgical Anatomy of Left Lobe of the Liver (Couinaud's and Healey's Anatomy) through Korean Cadaver Liver Dissection

PURPOSE: Couinaud described segment IV as being equivalent to segments II and III, as the umbilical portion of the portal vein (PV), and its equal branch of segment II, originated from the transverse portion of the PV. On the contrary, Healey suggested the presence of left lateral and medial segments, on the basis of umbilical fissure. Recently, some author have claimed the branch of segment II originated from the distal portion of the ligamentum venosum (LV), and that this branch was not equal to, only a branch of, the umbilical portion. Our goal was to evaluate the surgical anatomy of the left lobe of the liver through dissecting Korean cadavers. METHODS: The number of cadavers dissected totaled 10. PV, its branches, and the LV were dissected and the length of the transverse portion measured. The distance between the origin of the transverse portion and that of the segment II branch were also measured. RESULTS: The branch of segment II originated from the distal portion of the LV in all 10 cases. The length of the transverse portion was 18.8+/-5.8 mm, and the distance between the origins of the LV and segment II branch was 7.0+/-3.1 mm. CONCLUSION: Considering the embryology of the liver, as well as the above result, the umbilical portion and segment II branch were not equal anatomic structures. The umbilical portion and LV are equal anatomic structures. The branch of segment II is only one of the branches of the umbilical portion. We think Healey's classification is more accurate for the left lobe of the liver.