Use of Smooth Muscle Myosin Heavy Chain as an Effective Marker of Follicular Dendritic Cells.

Smooth muscle myosin heavy chain (SMMHC) is a major structural component of the contractile apparatus in smooth muscle cells. Even though it is considered a relatively specific marker for terminal smooth muscle cell differentiation, expression in other cell types such as follicular dendritic cells (FDCs) has rarely been reported. To determine whether SMMHC represents an effective FDC marker in lymphoid tissues, we compared the immunohistochemical results for SMMHC with those of the traditional FDC markers podoplanin (D2-40) and CD21. Paraffin sections of 44 lymphoid tissues were analyzed, including 31 cases of follicular hyperplasia, 6 cases of follicular lymphoma, 2 cases of peripheral T-cell lymphoma, 3 cases of diffuse large B-cell lymphoma arising in follicular lymphoma, 1 case of nodular sclerosis classical Hodgkin lymphoma, and 1 case of small lymphocytic lymphoma. There was no statistically significant difference between the number of SMMHC-positive and D2-40-positive or CD21 lymph nodes (P>0.05). The extent and intensity of SMMHC-positive FDCs were similar to those of D2-40-positive FDCs (P=0.127 and 0.733, respectively), but significantly lower compared with those of CD21 cells (P=0.009 and 0.00002, respectively). However, in contrast to CD21 which was also positive in some germinal center B cells, SMMHC expression was restricted to FDCs. Our results indicate that SMMHC is an excellent marker for FDCs and can be particularly helpful in demonstrating the underlying architecture in lymphoid processes.

Classification of non-Hodgkin lymphoma in Central and South America: a review of 1028 cases.

The distribution of non-Hodgkin lymphoma (NHL) subtypes differs around the world but a systematic study of Latin America has not been done. Therefore, we evaluated the relative frequencies of NHL subtypes in Central and South America (CSA). Five expert hematopathologists classified consecutive cases of NHL from 5 CSA countries using the WHO classification and compared them to 400 cases from North America (NA). Among the 1028 CSA cases, the proportions of B- and T-cell NHL and the sex distribution were similar to NA. However, the median age of B-cell NHL in CSA (59 years) was significantly lower than in NA (66 years; P < .0001). The distribution of high-grade (52.9%) and low-grade (47.1%) mature B-cell NHL in CSA was also significantly different from NA (37.5% and 62.5%; P < .0001). Diffuse large B-cell lymphoma was more common in CSA (40%) than in NA (29.2%; P < .0001), whereas the frequency of follicular lymphoma was similar in Argentina (34.1%) and NA (33.8%), and higher than the rest of CSA (17%; P < .001). Extranodal NK/T-cell NHL was also more common in CSA (P < .0001). Our study provides new objective evidence that the distribution of NHL subtypes varies significantly by geographic region and should prompt epidemiologic studies to explain these differences.

Falla hepatica fulminante: forma atipica de presentacion de insuficiencia cardiaca / Fulminant hepatic failure: atypical form of cardiac failure presentation

La insuficiencia cardíaca puede presentar como manifestación clínica la enfermedad hepática congestiva. En el shock cardiogénico puede aparecer falla hepática aguda por isquemia hepática. Presentamos una paciente que con antecedentes de insuficiencia cardíaca crónica ingresa a nuestro servicio por presentar mal estado general asociado a deterioro progresivo del hepatograma, del tiempo de protrombina y de la función renal. Las serologías virales y los autoanticuerpos fueron negativos. No tenía antecedentes de contacto con hepatotóxicos. En su evolución presentó encefalopatía sin evidencias iniciales de shock. Al cuarto día de internación presenta shock cardiogénico, con manifestaciones del laboratorio compatibles con isquemia y congestión hepáticas. La paciente fallece 24 horas después. La histología demostró cambios compatibles con isquemia hepática. Se han descripto varios casos de hepatopatías crónicas sin causa evidente que resultaron ser manifestaciones secundarias a enfermedades cardiológicas, especialmente pericarditis constrictiva o miocarditis restrictivas. En este caso la paciente presentó falla hepática aguda sin evidencia inicial de mayor deterioro de su cardiopatía previa. Con este caso queremos destacar la importancia de las causas cardiológicas como probables etiologías de hepatopatías sin causa aparente.

Falla hepatica fulminante: forma atipica de presentacion de insuficiencia cardiaca / Fulminant hepatic failure: atypical form of cardiac failure presentation

La insuficiencia cardíaca puede presentar como manifestación clínica la enfermedad hepática congestiva. En el shock cardiogénico puede aparecer falla hepática aguda por isquemia hepática. Presentamos una paciente que con antecedentes de insuficiencia cardíaca crónica ingresa a nuestro servicio por presentar mal estado general asociado a deterioro progresivo del hepatograma, del tiempo de protrombina y de la función renal. Las serologías virales y los autoanticuerpos fueron negativos. No tenía antecedentes de contacto con hepatotóxicos. En su evolución presentó encefalopatía sin evidencias iniciales de shock. Al cuarto día de internación presenta shock cardiogénico, con manifestaciones del laboratorio compatibles con isquemia y congestión hepáticas. La paciente fallece 24 horas después. La histología demostró cambios compatibles con isquemia hepática. Se han descripto varios casos de hepatopatías crónicas sin causa evidente que resultaron ser manifestaciones secundarias a enfermedades cardiológicas, especialmente pericarditis constrictiva o miocarditis restrictivas. En este caso la paciente presentó falla hepática aguda sin evidencia inicial de mayor deterioro de su cardiopatía previa. Con este caso queremos destacar la importancia de las causas cardiológicas como probables etiologías de hepatopatías sin causa aparente. (AU)