SECTION 1
Oral Cavity

Chase Heaton

CASE 1

Babak Givi

History of Present Illness

A 53‐year‐old man presents with a 1‐month history of tongue soreness and pain. He has not noticed any change in voice, difficulty swallowing, or a neck mass. However, the tongue pain is persistent and has not gone away with over‐the‐counter medications. His past medical history includes type II diabetes, controlled with oral agents, and hypertension. He does not smoke and has no history of tobacco or alcohol abuse. No other past medical history was identified.

Physical Examination

No palpable neck mass was identified. Oral cavity exam shows a slightly raised lesion on the right lateral tongue, which is soft and tender to palpation, measuring 1 cm in diameter (see Figure 1.1). There is no mass noted deep to the lesion. The rest of the exam, including fiberoptic laryngoscopy, is within normal limits.

Management

Question: What would you recommend next?

Answer: Tissue sampling with a punch or incisional biopsy of the lesion, preferably from the corner of the lesion.

Question: The biopsy shows squamous cell carcinoma (SCC ), moderately differentiated, with a depth of invasion of at least 4 mm (punch biopsy specimen with tumor transected at the base). What would you recommend next in the workup?

Answer: Imaging of the neck is usually recommended to assess lymph node involvement. A computed tomography (CT) scan with contrast or an ultrasound of the neck (which can be performed in the clinic) are both reasonable first options. The risk of distant metastases in early (T1 and T2) oral cavity SCC is extremely low. Therefore, extensive metastatic workup is not necessary. While positron emission tomography (PET)/CT has become more common, the evidence for its added benefit does not exist. Obtaining a chest CT to rule out lung metastases is considered adequate.

Question: A CT scan of the head and neck does not show any evidence of regional metastases. How would you clinically stage this disease?

Answer: Based on the AJCC staging manual, 8th Edition, the clinical stage is cT1N0Mx, stage I.

Question: What treatment would you recommend?

Answer: Early stage tongue cancer treatment is wide local excision of the primary tumor and addressing the regional lymph nodes. If the risk of regional lymph node metastases is presumed to be higher than 20%, an elective, selective neck dissection should be performed. Depth of invasion is a prognostic marker for the presence of occult nodal metastases in the cN0 neck. With a depth of invasion >3 mm, it is believed that the risk of occult nodal metastases is >20%, and therefore an elective neck dissection should be performed. In this scenario, the recommended treatment is wide local excision of the primary tumor with 1 cm margins and elective neck dissection (ipsilateral levels I–III, i.e., supra‐omohyoid neck dissection). Alternatively, sentinel node biopsy could be offered if adequate expertise in the treating facility exists.

Question: Patient undergoes sentinel node mapping followed by wide local excision and sentinel node biopsy. The tongue defect is repaired with biologic dressing and secondary intention closure. On lymphoscintigraphy, the sentinel node is located in an ipsilateral level II lymph node (Figure 1.2). Excisional biopsy and frozen section assessment shows metastatic SCC in the level II node. How would you proceed?

FIGURE 1.1 This photo demonstrates the patient's right lateral tongue ulceration.

FIGURE 1.2 This image shows the patient's fused CT‐ lymphoscintigraphy image. Note the uptake at the injection site and a right level II lymph node.

Answer: If the sentinel node is positive, completion lymphadenectomy (selective neck dissection, level I–IV) is recommended.

The patient recovers well from the operation. The final pathology report shows a 1.5 cm moderately differentiated SCC with a depth of invasion of 7 mm. All margins are free of tumor, with the closest margin being 8 mm from tumor. No lymphovascular or perineural invasion is identified. One out of 30 lymph nodes is positive for metastatic SCC without extranodal extension, measuring 1.9 cm (sentinel node).

Question: Based on these pathologic findings, what is the appropriate stage for this patient?

Answer: According to AJCC 8th Edition, tumors of the oral cavity with a depth of invasion of more than 5 mm are considered T2, even if the diameter is less than 2 cm. Therefore, the pathologic stage is pT2N1M0, stage III.

Question: What adjuvant treatment regimen, if any, would you recommend to this patient?

Answer: Since the disease is stage III, consideration of adjuvant treatment is warranted. Radiotherapy should be considered after discussion of the case at a multidisciplinary tumor board. The benefit of radiotherapy is not as clear in N1 disease; however, limited data exist that shows tumors with a depth of invasion of greater than 4 mm are at increased risk of regional failure without adjuvant therapy. Since there is no evidence of primary site positive margins or extranodal extension, there is no indication for adjuvant chemotherapy.

Question: The patient completes a course of adjuvant radiotherapy. What is your recommended regimen for follow‐up and clinical surveillance?

Answer: Based on National Comprehensive Cancer Network (NCCN ) guidelines, baseline imaging at 12 weeks after completion of adjuvant treatment should be obtained, followed by physical examination every 1–3 months in the first year post‐treatment and then 4–6 months in the second year. In years 3–5, a physical exam every 4–8 months is recommended and annually after 5 years. Annual thyroid‐stimulating hormone (TSH ) testing is recommended since the neck has received radiotherapy. Dental, nutrition, and ongoing depression evaluation are also recommended.

Key Points

• Oral tongue SCC is the most common malignancy of the oral cavity. The most important risk factors are tobacco, alcohol, poor dentition, diets low in fruits and vegetables, and Fanconi anemia.
• The risk of occult metastases in early stage oral cavity cancers is usually upward of 20%. Level I clinical trial evidence exists in the survival benefit of elective neck dissection in early stage tongue cancer and clinically negative cervical nodes when the depth of invasion is >3 mm. Currently, imaging techniques are not sensitive enough to identify occult metastases, and a negative CT or PET scan does not rule out microscopic metastases.
• Sentinel node biopsy in oral cavity cancers has been studied and shown to be reliable enough to identify the majority of occult metastases. Sentinel node sensitivity is reported as 86% with a negative predictive value of 95% based on the European Organization for Research and Treatment of Cancer.
• Recommended primary treatment of oral cavity cancers is primarily surgical. Wide local excision with a 1 cm margin and lymph node dissection (selective node dissection in clinically negative neck) is the current recommendation.
• Depth of invasion is an important prognostic factor. A depth of invasion of more than 3 mm is associated with an increased risk of lymph node metastases.
• The current indications for adjuvant radiotherapy are (i) close or positive margins, (ii) nodal involvement, (iii) perineural invasion, and (iv) advanced stage tumor (T3–4).
• Concurrent chemotherapy with platinum‐based agents is only recommended in positive margins or extranodal extension.

CASE 2

Babak Givi

History of Present Illness

A 64‐year‐old woman presents with a nonhealing ulcer of the right mandibular alveolus for the past month after extraction of the second molar. The lesion is not painful and does not bleed. She has a more than 40 pack‐year history of smoking and drinking two alcoholic drinks a day for the past 30 years. She does not report any history of other medical problems or prior malignancy.

Physical Examination

No palpable neck mass is identified. Oral cavity exam shows an ulcerative lesion limited to the occlusal surface of the right mandibular alveolus measuring 2 × 1 cm. The lesion is not tender to touch, does not extend to the buccal mucosa or floor of the mouth (see Figure 2.1). The rest of the exam, including flexible laryngoscopy, is within normal limits.

FIGURE 2.1 This photo demonstrates the ulcerative mucosal lesion of the right mandible gingiva.

Management

Question: What would you recommend next?

Answer: Since the lesion has been present for more than...