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Primary hepatic yolk sac tumour in children
ABSTRACTS
and a low grade component with features of a PXA. The diagnosis was confirmed by demonstrating immunohistochemical loss of INI1 expression, restricted to the rhabdoid areas. In addition, a significantly higher proportion of the rhabdoid cells showed loss of a chromosome 22 marker by fluorescent in situ hybridisation. To our knowledge this is the second reported case of an atypical teratoid rhabdoid tumour arising in the setting of a pleomorphic xanthoastrocytoma. We postulate that the AT/RT arose through secondary genetic events in the PXA, including INI1 inactivation. A MULTI-FACETED APPROACH IN PATHOLOGY TEACHING TO YEAR THREE MEDICAL UNDERGRADUATES Joon Joon Khoo Monash University, Malaysia Introduction: Pathology is the basis of medicine and forms the building blocks of medicine. It is the foundation on which students build their understanding of clinical conditions. Thus, it is very important that students’ foundation of learning pathology is strong and the students are given a good start to understand medicine and become competent doctors. Aims: A multi-faceted approach in pathology teaching to year three medical students was initiated to achieve the following aims: to influence students’ approach to learning, to give students a realtime experience, to teach students to learn to gather information at their own pace and way, and to maintain a sustained interest in them such that we impart in students a culture of self-directed learning. Methods: The methods of teaching used include blackboard online clinic-pathological case (CPC) learning, interactive CPC tutorials, real-time experience in laboratory visits, attending full autopsies, and pathological quizzes with incentives. Evaluation forms were given to students for the teaching they received. Results: The students rated highly the CPCs tutorials with a mean rate of 5.27 over a score of 1 to 6. Students were highly appreciative of the pathology quizzes and gave a mean score of 5.0. The students also felt they had received great value from participating in the laboratory visits and morgue visits. Similarly, the students felt that a visit to the morgue to attend autopsies should be made compulsory in the medical curriculum. Conclusion: A multi-faceted approach in pathology teaching to undergraduates is recommended over the routine class room teaching. PRIMARY HEPATIC YOLK SAC TUMOUR IN CHILDREN Jennifer J. S. Kim, Nicole Graf Department of Histopathology, The Children’s Hospital at Westmead, Sydney, NSW, Australia Aim: Yolk sac tumour is the most common histological subtype of the malignant germ cell tumours in children, which account for approximately 3% of all neoplasms in children. Yolk sac tumour arising in the liver is extremely rare, with fewer than 10 cases reported in the paediatric group in the recent literature. Methods: We evaluated two paediatric cases (a 2-year-old girl and 16-month-old boy), who presented with liver masses and raised serum alpha-fetoprotein (AFP). Results: The histological features were characteristic of yolk sac tumour with positive staining for AFP and low molecular cytokeratins.
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Discussion: We discuss the diagnostic difficulties arising from small biopsy specimens to distinguish yolk sac tumour from the most important differential diagnosis of hepatoblastoma, which is the most common primary malignant neoplasm of the liver below the age of 5 years. They have similar clinical presentations and both generally stain for AFP. We discuss the histological features and use of various immunohistochemistry markers to distinguish these tumours. The long term survival rates for hepatic primary yolk sac tumour remain unclear because of its rarity; however, yolk sac tumour in young infants is generally very chemosensitive with an overall good prognosis. PATHOGENESIS OF AUTOPHAGIC TRYPSIN ACTIVATION IN EXPERIMENTAL PANCREATITIS B. Kru¨ger, S. Malla, M. M. Lerch, J. Mayerle Division of Medical Biology, University of Rostock, Germany and Department of Medicine A, Ernst-Moritz-Arndt-University, Greifswald, Germany Aims: Intracellular protease activation, an initiating event for pancreatitis, was suggested to begin in autophagosomes. We tested whether intracellular trypsin activation depends on autophagy, or autophagy on trypsin activation, in the early phase of pancreatitis. Methods: We used mice expressing the fluorescent autophagy marker LC-3-GFP to prepare acini and to induce pancreatitis by supramaximal stimulation (10 nM CCK) in vitro. Trypsin activation was imaged by fluorescent microscopy (CBZ-Ile-Pro-ArgAMC). Results: Autophagosome formation was confirmed by the appearance of fluorescent vesicles in isolated acini of LC3-GFP-mice and a shift of LC3 to its membrane-bound LC3-II form. Significant levels were reached between 10 and 40 min following CCK stimulation. Premature trypsin activation also developed, but earlier during the first 10 min after CCK stimulation. Simultaneous fluorescent imaging of autophagosome formation (LC3-fluorescence) and trypsin activation (AMC-fluorescence) indicated that the two events arise in different compartments. Trypsin inhibition with gabexate-mesilate did not prevent autophagosome formation. Discussion: While autophagy has been shown to be important in regulating the ultimate levels of intrapancreatic protease activity and pancreatitis severity, the initial activation of trypsin develops neither in autophagosomes nor does it depend on autophagy. Onset of autophagy in the pancreas, in turn, does not require trypsin activation. IN SITU MANTLE CELL LYMPHOMA: CASE REPORT AND LITERATURE REVIEW Nazmoon Laila1, Simon Nazaretian2,3,4, Beena Kumar1, Ian Simpson1, Stephen Opat5 1 Department of Anatomical Pathology, Monash Medical Centre (MMC), 2The Royal Children and Womens Hospital, 3Monash University, Department of Anatomy and Developmental Biology, 4 Healthscope Pathology, and 5Department of Haematology, MMC, Melbourne, Vic, Australia We present a rare case of in situ mantle cell lymphoma in an 87-year-old female who presented with enlarged left inguinal and left axillary lymph node and no B symptoms. The morphology on
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
and a low grade component with features of a PXA. The diagnosis was confirmed by demonstrating immunohistochemical loss of INI1 expression, restricted to the rhabdoid areas. In addition, a significantly higher proportion of the rhabdoid cells showed loss of a chromosome 22 marker by fluorescent in situ hybridisation. To our knowledge this is the second reported case of an atypical teratoid rhabdoid tumour arising in the setting of a pleomorphic xanthoastrocytoma. We postulate that the AT/RT arose through secondary genetic events in the PXA, including INI1 inactivation. A MULTI-FACETED APPROACH IN PATHOLOGY TEACHING TO YEAR THREE MEDICAL UNDERGRADUATES Joon Joon Khoo Monash University, Malaysia Introduction: Pathology is the basis of medicine and forms the building blocks of medicine. It is the foundation on which students build their understanding of clinical conditions. Thus, it is very important that students’ foundation of learning pathology is strong and the students are given a good start to understand medicine and become competent doctors. Aims: A multi-faceted approach in pathology teaching to year three medical students was initiated to achieve the following aims: to influence students’ approach to learning, to give students a realtime experience, to teach students to learn to gather information at their own pace and way, and to maintain a sustained interest in them such that we impart in students a culture of self-directed learning. Methods: The methods of teaching used include blackboard online clinic-pathological case (CPC) learning, interactive CPC tutorials, real-time experience in laboratory visits, attending full autopsies, and pathological quizzes with incentives. Evaluation forms were given to students for the teaching they received. Results: The students rated highly the CPCs tutorials with a mean rate of 5.27 over a score of 1 to 6. Students were highly appreciative of the pathology quizzes and gave a mean score of 5.0. The students also felt they had received great value from participating in the laboratory visits and morgue visits. Similarly, the students felt that a visit to the morgue to attend autopsies should be made compulsory in the medical curriculum. Conclusion: A multi-faceted approach in pathology teaching to undergraduates is recommended over the routine class room teaching. PRIMARY HEPATIC YOLK SAC TUMOUR IN CHILDREN Jennifer J. S. Kim, Nicole Graf Department of Histopathology, The Children’s Hospital at Westmead, Sydney, NSW, Australia Aim: Yolk sac tumour is the most common histological subtype of the malignant germ cell tumours in children, which account for approximately 3% of all neoplasms in children. Yolk sac tumour arising in the liver is extremely rare, with fewer than 10 cases reported in the paediatric group in the recent literature. Methods: We evaluated two paediatric cases (a 2-year-old girl and 16-month-old boy), who presented with liver masses and raised serum alpha-fetoprotein (AFP). Results: The histological features were characteristic of yolk sac tumour with positive staining for AFP and low molecular cytokeratins.
S77
Discussion: We discuss the diagnostic difficulties arising from small biopsy specimens to distinguish yolk sac tumour from the most important differential diagnosis of hepatoblastoma, which is the most common primary malignant neoplasm of the liver below the age of 5 years. They have similar clinical presentations and both generally stain for AFP. We discuss the histological features and use of various immunohistochemistry markers to distinguish these tumours. The long term survival rates for hepatic primary yolk sac tumour remain unclear because of its rarity; however, yolk sac tumour in young infants is generally very chemosensitive with an overall good prognosis. PATHOGENESIS OF AUTOPHAGIC TRYPSIN ACTIVATION IN EXPERIMENTAL PANCREATITIS B. Kru¨ger, S. Malla, M. M. Lerch, J. Mayerle Division of Medical Biology, University of Rostock, Germany and Department of Medicine A, Ernst-Moritz-Arndt-University, Greifswald, Germany Aims: Intracellular protease activation, an initiating event for pancreatitis, was suggested to begin in autophagosomes. We tested whether intracellular trypsin activation depends on autophagy, or autophagy on trypsin activation, in the early phase of pancreatitis. Methods: We used mice expressing the fluorescent autophagy marker LC-3-GFP to prepare acini and to induce pancreatitis by supramaximal stimulation (10 nM CCK) in vitro. Trypsin activation was imaged by fluorescent microscopy (CBZ-Ile-Pro-ArgAMC). Results: Autophagosome formation was confirmed by the appearance of fluorescent vesicles in isolated acini of LC3-GFP-mice and a shift of LC3 to its membrane-bound LC3-II form. Significant levels were reached between 10 and 40 min following CCK stimulation. Premature trypsin activation also developed, but earlier during the first 10 min after CCK stimulation. Simultaneous fluorescent imaging of autophagosome formation (LC3-fluorescence) and trypsin activation (AMC-fluorescence) indicated that the two events arise in different compartments. Trypsin inhibition with gabexate-mesilate did not prevent autophagosome formation. Discussion: While autophagy has been shown to be important in regulating the ultimate levels of intrapancreatic protease activity and pancreatitis severity, the initial activation of trypsin develops neither in autophagosomes nor does it depend on autophagy. Onset of autophagy in the pancreas, in turn, does not require trypsin activation. IN SITU MANTLE CELL LYMPHOMA: CASE REPORT AND LITERATURE REVIEW Nazmoon Laila1, Simon Nazaretian2,3,4, Beena Kumar1, Ian Simpson1, Stephen Opat5 1 Department of Anatomical Pathology, Monash Medical Centre (MMC), 2The Royal Children and Womens Hospital, 3Monash University, Department of Anatomy and Developmental Biology, 4 Healthscope Pathology, and 5Department of Haematology, MMC, Melbourne, Vic, Australia We present a rare case of in situ mantle cell lymphoma in an 87-year-old female who presented with enlarged left inguinal and left axillary lymph node and no B symptoms. The morphology on
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.