įigure 9 Contrast enhanced CT shows a reactive left preauricular, extrafascial parotid lymph node. The anterior nodes lie anterior or superficial to the facial vein, whereas the posterior subgroup is placed posterior or deep to it, in the vicinity and below the point of entry of the Stenson’s duct in the buccinators. These are divided into two groups according to their relationship to the anterior facial vein. The buccinator group lymph nodes are found overlying the buccinator muscle and its fascia, or in the fat of the buccinator space (Figure 3). A striking findings with mandibular lymph nodes metastasis from head and neck cancer, is their association with a singular poorer outcome, with the survival rate dropping to 14.3 % in patients with positive facial nodes from 62.5 % for patients with negative facial nodes. Sheahan et al., reported their involvement in palatine tonsils, retromolar trigon, base of the tongue and floor of the mouth malignancy. These nodes are also of most interest to the head and neck surgeon, since they could be involved, even though rarely reported, in head and neck cancer. The efferent drainage is to the submandibular lymph vessels and nodes. The mandibular lymph nodes has its afferent drainage from the infraorbital and buccinator lymphatics as well as from the skin and subcutaneous tissues of the cheek, lower lip, and less commonly the gingiva, buccal mucosa, hard and soft palate. Keywords: lymph nodes head and neck lymphatic systemįigure 2 Axial contrast enhanced CT demonstrates a non-enlarged right mandibular lymph node reposing on the masseter muscle. We present a review of the anatomy of those lymph nodes groups, including their location, afferent and efferent drainage tracts accompanied by cross-sectional imaging CT examples. The more superficial groups, notably the occipital, parotid, mastoid, facial and superficial cervical lymph nodes groups were not well recognized in the radiology literature, probably because of their less frequent involvement in the more predominant pharyngeal and laryngeal mucosal malignancy, and seem to have been forgotten. The deep cervical lymph nodes, mainly placed along the jugulo carotid vessels, have been intensively reviewed in radiology and classified by well-established levels. The lymphatics of the head and neck area consist of superficial and deep nodes groups, which are connected by numerous small vessels, giving rise to a complex subcutaneous and deep lymphatic network. In patients with head and neck malignancy, knowledge of the lymphatic pathways relevant to tumor location is important for treatment preparation, both in radiation therapy and in surgery.
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