A 64-year-old man comes to the office due to a lump in his neck. He has a long history of using chewing tobacco. On examination, there is an ulcerative lesion in the left floor of mouth. There is also a firm, palpable, nontender left submandibular mass. Biopsy of the submandibular mass is shown in the exhibit. Which of the following is the most likely route of spread from the floor of mouth to the submandibular mass?
Cancer routes of spread | ||
Type | Definition | Examples |
Direct invasion | Extension into neighboring tissues |
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Lymphatics | Embolic drainage or invasion into lymphatic channels allows spread to regional lymph nodes |
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Hematogenous | Embolic spread through the vasculature (usually veins) |
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Transcoelomic | Spread throughout a body cavity |
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Perineural | Spread along nerves or nerve sheaths |
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This patient with an ulcerative lesion in the floor of mouth and ipsilateral lymphadenopathy in the submandibular area has a biopsy that shows malignant cells with atypical mitotic figures and keratin pearls, findings which are consistent with head and neck mucosal squamous cell carcinoma (HNSCC).
Most carcinomas, including head and neck squamous cell carcinoma, first spread from the primary site of the tumor to regional lymph nodes via the lymphatics. In this patient with a floor of mouth squamous cell carcinoma, the spread is to the upper anterior cervical lymph nodes, manifesting as submandibular lymphadenopathy.
Assessment of regional lymph node status is important for tumor staging based on the TNM staging system, which evaluates the size and characteristics of the Tumor, regional lymph Node involvement, and distant Metastases. The presence of metastases is indicative of advanced cancer and often confers a poor prognosis.
(Choice A) Direct invasion through the floor of mouth can occur in head and neck squamous cell carcinoma and result in extension to the submandibular space. However, it is likely to present as a large, fungating mass with local destruction (eg, bony invasion).
(Choice B) Field cancerization refers to widespread, premalignant damage to cells in a large area. It is thought to be responsible for the high rate of synchronous tumors in patients with head and neck squamous cell carcinomas.
(Choice D) Perineural invasion occurs in many cancers, including head and neck cancer, and conveys a poor prognosis. It may contribute to some symptoms of cancer, including numbness or pain, but is not responsible for disease in the lymph nodes of this patient.
(Choice E) Hematogenous spread of cancer typically follows venous drainage routes and is common in sarcomas and a few carcinomas (eg, renal cell carcinoma, hepatocellular carcinoma); however, it is not typical in head and neck squamous cell carcinoma.
Educational objective:
Head and neck squamous cell carcinomas typically spread first to the anterior cervical lymph nodes via the lymphatics. The involvement of anterior cervical lymph nodes affects the staging of the disease.