L'immunohistochimie dans le diagnostic des tumeurs des tissus mous

Les tumeurs des tissus mous (TTM) sont un ensemble heteroclite; rare et de diagnostic histopathologique parfois difficile. L'immunohistochimie constitue un moyen complementaire d'un apport decisif. Nous rapportons ici une serie de 36 TTM; dont le diagnostic comparatif a ete fait entre Dakar et Bordeaux avec parfois utilisation de l'immunohistochimie (IHC) dans cette derniere ville pour la confirmation du diagnostic definitif. L'IHC a permis de redresser le type histologique dans 100 % des tumeurs benignes (2/2) et dans 60 % des tumeurs malignes (6/10). Bien etant une aide incontournable; l'IHC ne peut ni remplacer ni preceder un examen histologique standard qui represente la cle du diagnostic a condition que le pathologiste soit experimente

Benign vs malignant soft tissue neoplasms: Limitations of magnetic resonance imaging.

Aims: Various features have been described in the literature to differentiate benign from malignant lesions. The aim of the present study was to study the accuracy of each of these features and that of magnetic resonance imaging (MRI) in diagnosing malignant lesions. Materials and Methods: Fifty-five consecutive patients presenting with neoplastic (both benign and malignant) lesions diagnosed clinically and on ultrasound were studied and their MRI features were compared with the findings on surgical exploration and histopathologic examination. Results: There were 32 (58%) benign and 23 (42%) malignant masses. Malignant masses were more common in patients older than 20 years (83%), and these had symptoms of less than 6 months duration (75%), as against benign lesions. The swelling was painful in 8 malignant masses and these were more common in the upper limbs (61%). Various features of malignant lesions were size more than 5 cm in 83%, change in signal intensity from homogenous on T1-weighted images to heterogenous on T2-weighted images in 74%, irregular margins in 74%, and heterogenous contrast enhancement in 91%. The accuracy of these features was 76%, 58%, 78%, and 60%, respectively. Most benign and malignant lesions were intramuscular in location. A significant number (38%) of benign lesions were located in the intermuscular facial plane. Definitive diagnosis was made in 42% of the lesions. Conclusions: MRI is an excellent modality for evaluating soft tissue neoplasms; however, prediction of a specific diagnosis and differentiation of malignant and benign lesions is not always possible.

Aspectos fisiopatológicos da disseminação de sarcomas / Aspects of physiopathology of sarcoma dissemination

Ao longo do processo tumoral, algumas células evadem mecanismos de vigilância intra e extracelular. Essas células adquirem a capacidade de invadir tecidos e colonizar órgãos a distância caracterizando os processos de invasão e metastatização, que caracterizam o câncer. Aqui, revisamos alguns dos elementos que caracterizam o processo de disseminação tumoral, comparando sarcomas, carcinomas e melanomas. Ressaltamos a participação de elementos celulares normais do hospedeiro como moduladores do processo de invasão tumoral. Diferentemente de células tumorais, geralmente heterogêneas e geneticamente menos estáveis, as células do hospedeiro que modulam o processo de disseminação são geneticamente estáveis e fenotipicamente homogêneas. Discutimos a necessidade de se modificar o alvo de estratégias antitumorais, centrado na célula tumoral, ampliando-o para incluir os elementos celulares normais (vasos neoformados) e elementos do sistema imune-agentes moduladores da progressão tumoral.

Sarcomas de tejido oseo y de tejido blando / Bone and soft tissue sarcomas

El presente trabajo es una revision de los pacientes con tumores Oseos y Tumores de partes Blandas atendidas en el Hospital Oncologico de Santa Cruz en el periodo 1986-1993 con 62 casos. No se incluyen los pacientes revisados en la consulta externa, solo aquellos pacientes internados.