PBL Case Research Articles

Oral and Extraoral Plasmablastic Lymphoma

Abstract Plasmablastic lymphoma (PBL), initially characterized as an aggressive lymphoma arising in the jaw and oral mucosa in HIV-infected patients, was recently reported to occur with extraoral manifestations, heterogeneous histologic findings, and variable association with immunodeficiency states. We reviewed clinical, morphologic, and immunophenotypic features of 13 cases of PBL to determine whether these different subtypes represent distinct morphologic and clinical entities. Two distinct subtypes of PBL were identified and classified as oral and extraoral PBL. The oral PBLs were strongly associated with HIV infection and commonly demonstrated plasmablastic morphologic features without plasmacytic differentiation. Extraoral PBLs tended to occur in patients with underlying non–HIV-related immunosuppression and universally demonstrated plasmacytic differentiation. The patients with oral PBL demonstrated better overall survival compared with patients with extraoral PBL (P = .02). Our findings suggest that PBL with oral and extraoral manifestation represent 2 distinct clinicopathologic entities.

Primary follicular and marginal-zone lymphoma of the breast: clinical features, prognostic factors and outcome: a study by the International Extranodal Lymphoma Study Group

BackgroundPrimary breast lymphoma (PBL) of low-grade histology is a rare disease. This multicentric retrospective study was carried out to determine clinical features, prognosis and relapse. Patients and methodsPatients with histologically proven, previously untreated follicular or marginal-zone PBL (MZL PBL) diagnosed from 1980 to 2003 were included in the study. Major end points were progression-free survival (PFS), overall survival (OS) and potential prognostic factors. ResultsWe collected data on 60 cases of PBL [36 follicular and 24 marginal-zone lymphoma (MZL)]. Stage was IE or IIE in 57 patients and IVE in three patients due to bilateral breast involvement. Surgery, chemotherapy and radiotherapy (RT), alone or in combination, were used as first-line treatments in 67%, 42% and 52% of patients, respectively. Overall response rate was 98%, with a 93% complete response rate. Five-year PFS were 56% for MZL and 49% for follicular PBL (P=0.62). Relapses were mostly in distant sites (18 of 23 cases); no patients relapsed within RT fields. ConclusionsOur data showed an indolent behaviour of MZL PBL, comparable to other primary extranodal MZL. Conversely, patients with follicular PBL had inferior PFS and OS when compared with limited-stage nodal follicular non-Hodgkin's lymphomas, suggesting an adverse prognostic role of primary breast localisation in this histological subgroup.

Websites of note

Websites of note

Case-based learning: developing patient- and student-centred learning

in our country, serving a population of 26 million people. There is thus a great need for doctors who are able to interpret their own radiographic investigations. For this reason, undergraduate basic radiology training in the new PBL curriculum was considered essential. What was done The cardio-respiratory course in the first year of study was identified as a suitable place in the programme to initiate basic radiological anatomy learning. The learning outcomes, content and cases were modified appropriately and relevant radiographic material for the cases were prepared. Students attended 2 small-group sessions in which the normal anatomy of chest radiographs was discussed and demonstrated in an interactive manner. These sessions were facilitated by a radiologist and supplemented the interpretation of chest radiographs in the PBL cases. Emphasis was put on chest radiography as this is the most common radiological investigation in clinical practice in developing countries. The educational impact of this learning strategy was evaluated by determining the ability of Year 1 and final year students in the identification of normal radiological anatomy visible on a chest radiograph. Unlike the Year 1 students, the final year students had been taught radiology in the traditional programme (discontinued in 2003) in large classroom lectures. Student and tutor satisfaction was assessed after the course using a self-administered questionnaire scored on a Likert scale (1 1⁄4 strongly disagree to 5 1⁄4 strongly agree). Evaluation of results and impact The use of PBL represents a new approach at our medical school and is aimed at conceptualising learning and making it relevant to clinical practice. The students found integration of radiological anatomy and investigations into the PBL cases exciting and motivating and the tutors enjoyed the experience. Thus the main objective of introducing radiological anatomy and investigations to Year 1 students was achieved. More importantly, Year 1 students performed just as well as final year students in a quiz requiring the identification of 12 anatomical structures on a chest radiograph. The mean scores achieved were 7 and 8 out of 12, respectively. This demonstrates that early, integrated exposure to radiological anatomy and investigations facilitates the learning of basic radiology by undergraduate students. This method of achieving basic competence in radiological investigation and interpretation skills is essential, given the shortage of radiologists in developing countries like Uganda. Correspondence: E Kiguli-Malwadde, Department of Radiology, Makerere University, PO Box 7072, Kampala, Uganda. Tel: 00 256 7 8241 0876; Fax: 00 256 4 153 2412; E-mail: malwadde@med.mak.ac.ug

High Grade Primary Breast Lymphoma: is it a Different Clinical Entity?

Primary lymphoma of the breast (PBL) is a rare neoplasm, its outcome remains unclear compared to other lymphomas. We performed a retrospective study of 19 cases of high grade PBL. There were 17 Diffuse large B cell lymphoma (DLBCL) and 2 follicular and diffuse grade 3 lymphomas. Four patients were treated with local treatment only, 15 received chemotherapy including 11 treated with CHOP or ACVBP regimens followed by involved field radiotherapy. The actuarial survival for the whole population was 38%. Three of the 4 patients treated only with a local treatment died of their lymphoma. Three patients progressed on therapy and 5 relapsed in the first year of follow-up including 2 central nervous system recurrences. Among the 11 patients treated with chemotherapy, 2 died of their lymphoma. The overall survival of this subgroup was 73% (median follow-up of 57 months). We observed, like others in the literature, a better prognosis for lymphomas co-expressing Bcl6 and CD 10. The treatment should be based on the same modalities, but including a CNS prophylaxis even if poor prognosis factors are lacking. A radical mastectomy increases the risk of treatment failure and has to be avoided.

University of California, Los Angeles, David Geffen School of Medicine at UCLA.

University of California, Los Angeles, David Geffen School of Medicine at UCLA.

Is there a problem with the problems in problem-based learning?

To determine the balance between acute and chronic medical problems in the PBL cases at 2 Australian medical schools. Analysis of 162 PBL cases. Cases concentrate on acute problems in young people and neglect chronic disease in the old. This imbalance may contribute to negative attitudes towards elderly patients and people with chronic disease.

Cultural sensitivity training in Canadian medical schools.

The authors describe the results of a survey they carried out in 2000 to determine the status of cultural sensitivity training in 16 Canadian medical schools using structured telephone interviews of associate and assistant deans or curriculum directors and curriculum coordinators. Their goal was to obtain a descriptive analysis of school-specific objectives, curriculum content, methods, and evaluation formats. The survey was prompted by the growing concern that in culturally diverse societies, medical education has failed to keep pace with the changing composition of the patient population. Only one of the eight schools that integrated cultural sensitivity within their objectives made explicit mention of the topic in its clerkship evaluation form. While seven of the 16 schools did not have any statement on cultural sensitivity in their curricular objectives, they integrated cultural sensitivity in their curricula using various educational methods, with PBL cases, lectures, and small-group discussions being the commonest formats. These educational methods were primarily offered to students in their first and second years. Student participation was required, but program lengths ranged from two to 40 hours. Additional findings for each school are presented. The authors conclude that while progress has been made, lack of adequate resources and a number of obstacles to inclusion of multicultural health content in curricula appear to remain ongoing problems. Further investment in faculty development and administrative staff support for a multicultural curriculum are needed, as is more research on effective curricular components.

PROBLEM-BASED LEARNING WITHIN ENDOCRINE PHYSIOLOGY LECTURES

Methods were needed to improve the interest of medical students in the 10-lecture Endocrine Physiology block at the end of the second semester of study. Other incentives for improvement included the possibility of attracting students into endocrine research electives and the pressure to improve teaching approaches that results from the high tuition they pay. The principal approach adopted was that of whole class problem-based learning sessions (PBLS) in which the lecture period begins with a brief overview of one to three simplified cases, followed by the usual didactic lecture. At the end of the lecture, each PBL case is read in detail, with several questions posed to the students. Their answers are then used to reinforce concepts from the lecture material. This method can also provide some continuity between lectures, either by using a case in several lectures to illustrate different points, or by posing a question at the beginning of class that illustrates a point from the prior lecture. The outcome of this approach has been very successful: student evaluations of the lecture block and their attendance have significantly improved.

Problem-Based Learning

Problem-based learning has been described for use in medical education and is thought to be a superior approach to traditional didactic methods. We describe the use of PBL as an innovative approach to the education and training of social workers on an interdisciplinary health care team. An actual PBL case is described, and a discussion of the advantages and disadvantages to this approach is presented. The use of PBL on interdisciplinary teams helps educate social workers to work effectively on teams, and educates other professionals about the social work role and how to utilize social work services effectively.

Sensitivity of High-Resolution Simulations of Hurricane Bob (1991) to Planetary Boundary Layer Parameterizations

The fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model is used to simulate Hurricane Bob (1991) using grids nested to high resolution (4 km). Tests are conducted to determine the sensitivity of the simulation to the available planetary boundary layer parameterizations, including the bulk aerodynamic, Blackadar, Medium-Range Forecast (MRF) model, and Burk–Thompson boundary layer schemes. Significant sensitivity is seen, with minimum central pressures varying by up to 16 mb and maximum winds by 15 m s−1. The Burk–Thompson and bulk aerodynamic boundary layer schemes produced the strongest storms while the MRF scheme produced the weakest storm. Simulated horizontal precipitation structures varied substantially between the different PBL schemes, suggesting that accurate forecasts of precipitation in hurricanes can be just as sensitive to the formulation of the PBL as they are to the cloud microphysical parameterizations. Each PBL scheme is different in its formulation of the vertical mixing within the PBL and the surface fluxes, with the exception of the MRF and Blackadar schemes, which share essentially the same surface flux parameterization. Detailed analyses of the PBL schemes describe the key differences in the surface fluxes and how they impact storm intensity. In order to isolate the effects of vertical mixing and surfaces fluxes, simulations were conducted in which each of the surface flux schemes was used in conjunction with the same vertical mixing scheme, and vice versa. These experiments indicate that simulated intensity is largely determined by the surface fluxes rather than by the vertical mixing, with the exception of the MRF PBL case, in which excessively deep vertical mixing acts to dry the lower PBL and reduce hurricane intensity. Simulations that vary only the surface fluxes suggest that the intensity of the simulated hurricane increases with increasing values of the ratio of the exchange coefficients for enthalpy and momentum, Ck/CD. However, even for identical values of Ck/CD, the simulated intensity varies depending on the wind speed dependence of the surface roughness parameter z0.