Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

By placing the patient on the stretcher, all care must be directed to preventing the so-called "second accident".

What practical diagnostic considerations should the physician make when receiving ECT?

On the basis of Del Río Hortega-Polak's classification of tumors of peripheral nerves, we only consider the two main types because of their frequency and topography: lemocytomas and lemocytofibromas. Lemocytomas (neurinomas, schwannomas or neurilemomas) are the most frequent in this series. Histogenesisin schwannic element is now recognized. They are single, circumscribed and well encapsuled tumors, with characteristic histology and fusiform elementsarranged in intertwined fascicles showing typical "palisade" figures. Even though sorne authors describe malign forms, the majority hold they do not exist. Del Río Hortega recognizes a "sarcomatoid" form in vlhich nuclear pleomorphysm is evident and at odds with a markedly benign biology. Lemocytofibromas (neurofibromas) are rarer; isolated forros are exceptional, they are generally multiple and a part of v. Recklinghausen's neurofibromatosis. Histogenesis is mixed and originates in Schwann's cellsand cells of fibroblastic component. They are benign, encapsuled, and its histology showing their double origin. Malign forms described are exclusively derived from fibroblastic element; their behaviour is that of any fibrosarcoma of other origin.

Sarcomas of muscular origin are frequently found in soft parts. Leiomyosarcomas are rare among them, althoug their incidence has increased as result of better interpretationof sarcomas formerly classified as fusocellular. Their most probable origin is in muscular elements of vessel -mainly venous- walls thus facilitatingspreading through bloodstream. They are genera!Jy infiltrating and may be limited, but never encapsulet; metastases are mainly Jocated in lung, liver and bones.Rhabdomyosarcomas form a complex and frequent tumoral complex having its origin in the mesenchyme which forms striated muscles. Three main types canbe distinguished which possibly respond to stages in ontogenic evolution of muscular cells: embryonal (50 % ), alv,eolar ( 40 % ) and pleomorphic adult type ( 10 % ) .They have in common indexes of presumptive. rhabdomyoblastic origin, especially existence of intracytoplasmatic glucogen and double striae. 'I'heir general characteristicsinclude Jargeness, infiltration and often, recurrence, as well as production of metastases through ood and Jymph.

Anatomical characteristics of myoblastomas of granulous cells and alveolar sarcomas of soft parts are described, with stress on morphological differences andbiological behaviour. The paper contains a brief summary of historical concept of both tumors. Histogenetic theories on its origin are discussed andneurogenic character is admited as the most Iikely, By means of histochemical detection techniques, the author finds great simi!arity between enzyme population ofboth tumors and sone components of nervous tissue.

Soft tissue sarcomas, group of difficult to precision, include malignant tumors derived from mesenchymal tissues, housed in the space between the hypodermis and the periosteum or between the hypodermis and the parenchymal organs

Vascular sarcomas have their origín in mesenchymatose angioforming cells. According to Cassinelli they should be termed "angiosarcomas", while Stout describestwo histological forms depending on whether proliferated element is endothelial (malign hemangioendothelioma) or is related to Zimmermann's pericytes (hemangiopericytoma).In the former, tumoral cells are inside the vascular basal and in the latter, outside. They are infiltrating tumors which cause metastasis mainly through the bloodstream. Lymphangiosarcomas are exceptional tumors and the only cases described are related to chronic post-mastectomy lymphoedema.

Synovial sarcoma is a rare. tumor of periarticular soft parts of limbs. It is formed by synovial cells v1hich adopt two different types; a synovial elementof epithelioid aspect covering inlets, forming pseudoacinus or simulating a membrane, in compact arrangement; and a fibromatous element with fusiform cellsarranged in fascicles. Growth of tumor is relatively slow, metastasis is produced through the blood system, and very often infiltrating regional ganglia; this is a fact to be born in mind in surgery.

Myxomas are rare tumors of soft parts with histological characteristics similar to that of primitive mesenchyme or embryonic mucuous tissue. They arelocal!y malignant but never produce metastasis; however if abscission is conservative they may recur. Myxomas, which are real neoplasias, should not be mistakenwith mucoid degeneration areas of other tumors of conjuntive origin.

Tumors in soft parts comprise !iposarcomas, which are second in frequency, evolution and prognosis. Evolution is slow and they seldom result in metastasis.Their therapy is almos! exclusively surgical.