Home About us Contact
|
Home About us Contact | ||
|
|
||
Superior Portion (superior + portion)
Selected AbstractsCytologic feature by squash preparation of pineal parenchyma tumor of intermediate differentiationDIAGNOSTIC CYTOPATHOLOGY, Issue 10 2008Keiji Shimada M.D., Ph.D. Abstract Pineal parenchyma tumor of intermediate differentiation (PPTID) is a very rare intracranial tumor, and pathological investigation limited to immunohistological and ultrastructural analyses have been published to date. Although intraoperative cytology is one of the important approaches for initial diagnosis in brain tumors, no or little studies on cellular morphology of PPTID have been demonstrated due to its rarity. We report here cytological features of PPTID obtained from stereotactic surgical specimens in a case of 27-year-old female manifested by dizziness and diplopia. Brain MRI revealed an unhomogeneously enhanced, large-sized tumor (56 × 52 × 60 mm) mainly located in the pineal region expanding from the midbrain to superior portion of the cerebellum and the fourth ventricle. Squash cytology showed increased nucleocytoplasmic ratio, hyperchromatic nuclei, and small rosette-like cell cluster but cellular pleomorphism was mild to moderate and necrotic background was not observed. Histology showed high cellularity, moderate nuclear atypia, and small rosette formation but neither bizarre tumor cells nor necrosis was present. Mitotic counts were very low (less than 1 per 10 high-power fields) and the MIB-1 labeling index was relatively high (10.1%). Tumor cells were immunohistochemically positive for neural markers such as synaptophysin, neurospecific enolase but not for glial fibrillary acidic protein or S-100. In some parts, cells were strongly reactive for neurofilament protein. Taken together, we made a final diagnosis of PPTID. This is the first presentation of cytological analysis by squash preparation that gives an important clue to accurate diagnosis of pineal parenchymal tumor and to understand its malignant potential. Diagn. Cytopathol. 2008;36:749,753. © 2008 Wiley-Liss, Inc. [source] Assessment of Pulmonary Vein Anatomic Variability by Magnetic Resonance Imaging:JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2004Implications for Catheter Ablation Techniques for Atrial Fibrillation Introduction: Pulmonary vein (PV) isolation for atrial fibrillation (AF) currently is performed using either an ostial or an extra-ostial approach. The objective of this study was to analyze by three-dimensional (3D) magnetic resonance angiography (MRA) the anatomy of the PVs in order to detect structural variability that would impact the choice of ablation approach. Methods and Results: Three-dimensional MRA was performed in 105 patients undergoing PV isolation. The ostial diameter, branching pattern, and PV angulation were analyzed. Fifty-nine (56%) patients had the typical pattern of 4 PVs with 4 separate ostia, 30 (29%) patients had an additional PV, and 18 (17%) patients had a left common PV trunk. In two patients, there were three right-sided veins and a common left-sided trunk, giving rise to four ostia: three on the right and one on the left. Two different populations of right middle PVs were noted: one where the additional vein projected anteriorly to drain the right middle lobe and one posterior to drain the superior portion of the right lower lobe. The average intrapatient variability in PV diameter was 7.9 ± 4.2 mm. The PV ostium was <10 mm in 26 (25%) patients and >25 mm in 15 (14%) patients. The first branch originated 6.7 ± 2.3 mm from the ostium. The left superior, right superior, right inferior, and left inferior PVs were found to enter the left atrium at the following angles: 32 ± 13°, 131 ± 11°, 206 ± 16°, and 329 ± 14°, respectively. Forty-nine patients (47%) had at least one funnel shaped PV. Conclusion: This largest PV imaging study to date demonstrates that MRA is a valuable tool that allows detection of marked intrapatient and interpatient anatomic variability of the PVs. These findings suggest that, at least in some patients, circumferential extra-ostial left atrial encirclement of the PVs may be preferable to ostial PV isolation. These findings also may have significant implications on the future development of coil- and balloon-based catheter ablation designs for AF ablation. (J Cardiovasc Electrophysiol, Vol. 15, pp. 387-393, April 2004) [source] The "safe zone" in medial percutaneous calcaneal pin placementCLINICAL ANATOMY, Issue 4 2009Zakareya Gamie Abstract Percutaneous pin insertion into the medial calcaneus places a number of structures at risk. Evidence suggests that the greatest risk is to the medial calcaneal nerve (MCN). The medial calcaneal region of 24 cadavers was dissected to determine the major structures at risk. By using four palpable anatomical landmarks, the inferior tip of the medial malleolus (point A), the posterior superior portion of the calcaneal tuberosity (point B), the navicular tuberosity (point C), and the medial process of the calcaneal tuberosity (point D), we attempted to define the safe zone taking into account all possible variables in our dissections including ankle position, side, gender, and possible anatomical variations of the MCN. The commonest arrangement of the MCN was two MCNs that arose independently, one arising before the bifurcation of the tibial nerve and the other arising from the medial plantar nerve. A zone could be defined posterior to 75% of the distance along the lines AB, CD, AD, and CB which would avoid most structures. The posterior branches of the MCN, however, would still be at risk and placing the pin too far posteriorly risks an avulsion fracture. This is the first study to employ four palpable anatomical landmarks to identify a zone to minimize damage to neurovascular structures. It may not be possible, however, to avoid injury of the MCN and consequent sensory loss to the sole of the foot. foot. Clin. Anat. 22:523,529, 2009. © 2009 Wiley-Liss, Inc. [source] Review of the anatomic concepts in relation to the retrorectal space and endopelvic fascia: Waldeyer's fascia and the rectosacral fasciaCOLORECTAL DISEASE, Issue 3 2008J. García-Armengol Abstract Objective, A precise anatomical study of the fascias within the retrorectal space is reported, analyzing and clarifying the anatomical concepts previously employed to describe Waldeyer's and the rectosacral fascia. Method, The pelvis was dissected in 15 cadavers (10 males and five females). All specimens were divided in the median sagittal plane including the middle axis of the anal canal, to allow a correct visualization of and access to the retrorectal space. Results, The retrorectal space was limited anteriorly by the rectum and posterior mesorectum covered by a fine visceral fascia, and posteriorly by the sacrum covered by the parietal presacral fascia. The rectosacral fascia divided the retrorectal space into inferior and superior portions in 80% of the male and 100% of the female specimens. It originated from the presacral parietal fascia at the level of S2 in 15%, S3 in 38% and S4 in 46% of specimens. In all cases it passed caudally to join the rectal visceral fascia 3,5 cm above the anorectal junction. As described by Waldeyer, the floor of the retrorectal space is formed by the fusion of the presacral parietal fascia and the rectal visceral fascia and lies above the levator ani muscle at the level of the anorectal junction. Conclusion, The rectosacral fascia divides the retrorectal space into inferior and superior portions. This must be differentiated from Waldeyer's description of the fascia lying in the inferior limit of the retrorectal space, formed by the fusion of the rectal visceral and parietal fascias. [source] | ||||||||||