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Site
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Pattern of lymph node metastasis (Wurman et al)
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lower lip, lateral
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ipsilateral submandibular and submental nodes
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lower lip, central
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bilateral submandibular and submental nodes
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upper lip
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parotid, preauricular, facial and submandibular nodes
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Factors associated with lymph node metastasis:
(1) tumor thickness
(2) perineural invasion (metastasis present in 60%)
(3) pathologic grade (metastasis present in 92% of grade 4 tumors)
(4) dispersed pattern (metastasis present in 77%)
(5) locally recurrent tumors
(6) tumors showing spontaneous ulceration
Different patterns shown (Frierson and Cooper):
(1) pushing borders
(2) discrete islands and nests with or without protrusions
(3) dispersed, with tumors diffuse, disorganized or completely haphazard
Tumor thickness:
• Tumor thickness is the maximal vertical thickness from the surface of the tumor to the deepest point of invasion, excluding surface keratin, parakeratin and inflammatory exudate.
• Onerci et al found a thickness > 5 mm was associated with a significant increase in lymph node metastasis.
• Frierson and Cooper found 74% of patients with a depth >= 6 mm had metastases. Tumors with a thickness <= 3 mm may rarely metastasize, while about 17% of those > 3 and < 6 mm metastasized (Table 2, page 351).
• Stein and Tahan referred to depth of invasion but measured this as the measurement from the most superficial cell layer to the deepest penetration of tumor cells. They found that all tumors with a depth of invasion > 6 mm (only 3 cases) developed metastases while metastases could occur if the depth of invasion was > 2 mm.
