Buccal Carcinoma Workup

See the list below:

• General preoperative workup should be based upon multiple factors, especially the extent of the patient's surgery and pre-existing medical conditions. Useful laboratory tests include the following:

  • Complete blood count (CBC), electrolytes, blood urea nitrogen (BUN), and creatinine (These provide a general screen for anemia, infection, electrolyte disturbance, and renal abnormalities.)

  • Prothrombin time (PT), activated partial thromboplastin time (aPTT), and international normalized ratio (These are used to screen for coagulopathy.)

  • Liver function and gamma-glutamyl transpeptidase (GGT) tests (These screen for alcoholic liver damage or distant metastatic disease.)

  • Blood typing and cross-matching (These are indicated for patients with anemia or those undergoing extensive surgery with a risk of significant blood loss.)

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• Chest radiographs, to include posteroanterior (PA) and lateral views, which will provide the following:

  • An assessment for pulmonary metastases or a synchronous lung tumor

  • An assessment for chronic lung disease, which is common in patients with head and neck cancer

• Contrast-enhanced CT scanning or MRI of the primary site and neck is helpful for the following reasons:

  • They provide staging information of both the primary tumor and neck, as well as for treatment planning.

  • They improve the diagnostic yield of physical examination alone in assessing for adenopathy and bone invasion.

  • They allow assessment of the depth and extent of the tumor and are used to evaluate the cervical lymph nodes.

  • They can provide valuable information about the resectability of advanced disease, including the relationship of disease to the carotid artery, cervical spine, and skull base. Bone windows are particularly helpful in assessing bone invasion of the mandible or maxilla.

  • MRI provides better soft-tissue delineation than does CT, and dental artifacts do not affect MRIs. This advantage may be most relevant in cases with posterior spread of the tumor into the masticator space and toward the skull base.

  • MRI can also be used to assess bone invasion by showing marrow replacement on T1-weighted images; however, osteomyelitis, osteoradionecrosis, or previous radiation may produce a similar appearance.

  • They are often complementary.

• Chest CT scanning and positron emission tomography (PET) scanning may both be used for metastatic workup.

  • Chest CT may be used primarily or secondarily if an abnormality is identified on chest radiographs.

  • PET has an increasing role in the workup of head and neck cancer. Currently, it is supplementary to physical examination and diagnostic imaging techniques such as MRI and CT. PET can be beneficial in confirming the primary tumor and assessing cervical adenopathy and distant metastases.

• Panorex imaging (mandibular orthopantomography) may be used to evaluate mandibular invasion in conjunction with CT scanning and clinical examination. It is also valuable in dental assessments of patients in whom radiation therapy is considered.

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• Biopsy

  • Any suspicious or nonhealing lesion of the buccal mucosa should be biopsied for histopathologic examination.

  • Incisional biopsy is useful for most lesions unless they are small enough that excisional biopsy can be done without significant morbidity.

  • Repeat excision with adequate margins may be required if the results of excisional biopsy are positive for carcinoma.

• Examination under anesthesia and panendoscopy

  • Involves inspection and palpation of the oral cavity and oropharynx, direct laryngoscopic examination of the hypopharynx and larynx, and endoscopic evaluation of the esophagus, trachea, and nasopharynx as indicated.

  • Can often be done at the time of planned resection.

Squamous cell carcinoma is the most common malignancy of the buccal mucosa, accounting for more than 90% of cases. Other less common malignancies include carcinoma arising from minor salivary glands, mucosal melanoma, lymphoma, and Kaposi sarcoma.

Classic histologic features of squamous cell carcinoma include atypical epithelial cells infiltrating the basement membrane, with intercellular bridges and keratin formation depending on the degree of differentiation. Squamous cell carcinoma stains positive for keratin.

Buccal carcinoma is staged using the American Joint Commission on Cancer (AJCC) Staging System for the oral cavity. The last modification to this staging system was 2002. Staging is based on findings from clinical examination, endoscopic evaluation, and diagnostic imaging. Staging may be modified on the basis of the pathologic findings.

The tumor, metastases, and nodes (TNM) classification is an expression of the anatomic extent of a primary tumor (T), neck disease (N) and metastases (M). The stage grouping condenses the different TNM combinations into groups, with each stage being homogenous with respect to survival.

• Primary tumor (T)

  • Tx - Primary tumor cannot be assessed

  • T0 - No evidence of primary tumor

  • Tis - Carcinoma in situ

  • T1 - Tumor no larger than 2 cm in greatest dimension

  • T2 – Tumor larger than 2 cm but smaller than 4 cm in greatest dimension

  • T3 - Tumor larger than 4 cm in greatest dimension

  • T4a - Tumor invading adjacent structures (eg, through cortical bone, into the deep [extrinsic] muscles of the tongue, maxillary sinus, or skin of the face)

  • T4b - Tumor invades masticator space, pterygoid plates, or skull base and/or encases internal carotid artery

• Regional lymph nodes

  • NX - Regional lymph nodes cannot be assessed

  • N0 - No regional lymph node metastasis

  • N1 - Metastasis in a single ipsilateral lymph node, 3 cm or less in greatest dimension

  • N2a - Metastasis in a single ipsilateral lymph node larger than 3 cm but smaller than 6 cm in greatest dimension

  • N2b - Metastases in multiple ipsilateral lymph nodes, none larger than 6 cm in greatest dimension

  • N2c - Metastases in bilateral or contralateral lymph nodes, none larger than 6 cm in greatest dimension

  • N3 - Metastases in a lymph node larger than 6 cm in greatest dimension

  • Distant metastases

    • MX - Distant metastasis not assessable

    • M0 - No distant metastasis

    • M1 - Distant metastasis

• Stages are defined as follows:

  • Stage 0 - Tis N0 M0

  • Stage 1 - T1 N0 M0

  • Stage 2 - T2 N0 M0

  • Stage 3 - T3 N0 M0; T1, T2, or T3 N1 M0

  • Stage 4a - T4a N0 M0; T4a N1 M0; T1, T2, T3 or T4a N2 M0

  • Stage 4b – Any T N3 M0; T4b any N M0

  • Stage 4c - Any T any N M1