Linfonodos cervicais: um dilema para o ultra-sonografista

Abstract

A análise dos linfonodos cervicais é um assunto complexo, na medida em que obtemos, por vezes, padrões de imagens superponíveis para os processos benignos - reacionais (infecciosos específicos e inespecíficos) - e para os malignos - doenças neoplásicas (linfoproliferativas e metastáticas). O seguimento adequado das linfadenopatias também requer do examinador detalhamento topográfico e descrição dos aspectos ecográficos relevantes. Realizamos revisão literária com os objetivos de ressaltar os critérios ultra-sonográficos mais significantes (modo-B e dúplex-Doppler colorido) e fazer analogia aos reparos anatômicos utilizados na tomografia computadorizada, para uniformizar a descrição topográfica dos níveis linfonodais por meio da ultra-sonografia. Os aspectos avaliados ao modo-B foram: número (se agrupados ou isolado), forma, hilo ecogênico central, ecotextura/ecogenicidade, presença de calcificações, necrose e/ou hemorragia interna, dimensões, contornos (disseminação extracapsular). Ao dúplex-Doppler colorido os aspectos avaliados foram: padrão de vascularização e análise espectral - índice de resistividade e índice de pulsatilidade. Existem padrões ultra-sonográficos freqüentemente descritos nos linfonodos malignos como morfologia globosa, hipoecogenicidade marcada, vascularização predominantemente periférica e índice de resistividade elevado, porém a análise deve ser multifatorial, levando-se em conta os parâmetros ao modo-B e ao dúplex-Doppler colorido.

Ultrasonography for lymph nodes metastasis identification in bitches with mammary neoplasms

“…According to Chammas et al . 28 , inflamed lymphoid structures tend to increase their size proportionally in all planes whereas neoplastic lymph nodes grow disproportionately, losing their original shape, like that observed in the present study.…”

“…The B-mode qualitative parameters (echogenicity and echotexture) did not demonstrate effectiveness to differentiate lymphoid tissue with metastasis nor reactive, corroborating with the previous reports 15,17,25 . The presence of necrotic, liquefaction or haemorrhagic areas, or areas that intersect normal and with tumour alterations tissues, micro calcifications and gross calcifications 13,28 promote a tissue variability in the lymph nodes, which results in visualization of heterogeneous echotexture in all tissues evaluated 17,25 . Regarding echogenicity, variations can be observed in tissues with or without metastasis in women, which establish relation between reduction of echogenicity and increase in cellularity, observed in lesions as basic as hyperplasia 30 .…”

Ultrasound evaluation of the morphometric patterns of lymph nodes of the head and neck in young and middle-aged individuals

“…The subjects who participated in this study did not report any health complaints. Features that can indicate malignancy, such as necrosis, calcification, extracapsular spread, and vascularization ( 3 ) , were not observed in any of the lymph nodes evaluated. The elongated shape and echogenic hila observed for the cervical lymph nodes evaluated in the present study correspond to what has been described in the literature ( 3 , 5 ) .…”

“…The use of imaging methods to evaluate the characteristics of those lymph nodes assists the physician in the diagnostic process ( 2 ) , given that the clinical examination alone is often insufficient for a proper evaluation. The use of ultrasound allows aspects such as the number, shape, size, hilum, and cortex of the lymph nodes, as well as necrosis, calcification, extracapsular spread, and vascularization, to be evaluated ( 3 ) .…”

“…On ultrasound, benign lymph nodes generally have an oval or elongated shape, with an echogenic hilum, and range from 0.1 to 2.5 cm in length, unless they contain calcifications or show cystic degeneration ( 3 , 5 ) . In contrast, those in which metastasis is strongly suspected are rounded, generally hypoechoic, with loss of hilum, and can present calcifications or cystic degeneration.…”