eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > Head & Neck Surgery

Malignant Tumors of the Tonsil: Workup

Author: Gerard Domanowski, MD †, Former Associate Chair, Former Associate Professor in Pathology, Former Associate Professor of Otolaryngology and Oral Surgery, Department of Pathology, McGill University Health Center
Contributor Information and Disclosures

Updated: Feb 14, 2007

Workup

Laboratory Studies

• Liver function tests: Knowledge of hepatic function is necessary because (1) the patient's dietary and ethanol histories frequently lead to poor function, (2) hepatically metabolized chemotherapeutic agents or other medications (eg, pain medication) may be used, and (3) liver metastases are always possible.
• Pulmonary function tests:
  • Any head and neck surgery carries additional risks of perioperative and postoperative respiratory complications.
  • Respiratory reserve is a necessary bit of knowledge before such surgery is performed.
• Renal function tests: When certain chemotherapeutic agents are considered, renal function tests are necessary to ascertain whether the patient can eliminate agents that are handled by the kidneys.
• Clotting and coagulation studies (including platelet count, typing, cross-matching)
  • The head and neck is one of the richest areas of vascularity in the human body.
  • Hemorrhage is one of the biggest problems in tonsillar surgery.
  • Having transfusion material available is wise.

Imaging Studies

• Plain chest radiography is necessary to evaluate for the possibility of pulmonary metastasis.
• CT scanning of the neck, bilaterally, with and without contrast, is necessary to evaluate for metastases and to assess the extent of the tumor. In addition, if extended upward to include the bony areas, bone invasion is part of the new knowledge base. This is essential in staging tonsillar tumors.
• MRI is also extremely useful for assessing tumor size and soft tissue invasion.

Diagnostic Procedures

• Biopsy is the only tool for obtaining diagnostic tissue.
  • Tonsillar malignancies may be lymphoma; therefore, the pathologist and team should be immediately ready to handle the tissue properly.
  • Special fixatives must be prepared. Some tissue may be needed for fresh studies, which are time dependent and require immediate handling. Some tissue should be frozen in liquid nitrogen. Given the nature of frozen sections and the type of unexpected events in a pathologist's day, alerting the pathologist 24 hours in advance of a possible lymphoma biopsy is wise.
  • Another very important consideration is the fact that squamous cell carcinomas commonly arise deep in the crypts. This necessitates the surgeon taking a deep biopsy so that the true neoplasm is not missed. Given the propensity for these lesions to bleed, this is a tricky procedure, and the surgeon should be ready for the unexpected.

Histologic Findings

Squamous cell carcinoma

Most palatine tonsil squamous cell carcinomas are moderately to poorly differentiated.

The following variants, although essentially squamous cell carcinomas, in this area have been described with some frequency:

• Basosquamous carcinoma Nonkeratinizing carcinoma (transitional cell or sinonasal type)
• Undifferentiated or lymphoepithelioma type

Lymphomas

In terms of the frequency of primary malignancies, lymphomas are second to squamous cell carcinomas. Because of the richness of lymphoid tissue in this area, all of the Waldeyer ring, the lingual tonsil, the nasopharynx, and the tonsils are frequent sites of lymphoma.

Most tonsillar lymphomas are diagnosed during the sixth and seventh decades of life; however, tonsillar lymphomas affect a wide age range, and tonsillar lymphoma should be in the differential diagnoses of tonsillar masses, regardless of age. Tonsillar lymphomas usually present as a painless mass in the tonsil, although sore throat is not uncommon. On occasion, otalgia is the presenting symptom.

Lymphoma type determination is crucial and can be achieved only with the help of special studies obtained by the pathologist. The cell and tissue markers used to type lymphomas are quite sensitive. These require fresh frozen tissue and unusual fixatives, in addition to immunohistochemical stains.

The quality of these studies is time dependent. Immediate examination of newly removed tissue by the pathologist is essential, if possible. The pathology staff should be alerted at least 24 hours in advance that a possible lymphoma is undergoing biopsy. Some fixatives may not be readily available, and liquid nitrogen for fresh frozen tissue should be made accessible. All of these may take some time. A one-day notice should ensure that proper handling is performed as soon as possible.

All of these studies help in the crucial determination of lymphoma type. Many require fresh or frozen tissue for immunohistochemical studies.

Most tonsillar carcinomas are diffuse non-Hodgkin large B-cell lymphomas.

Mucosa-associated lymphoid tissue (MALT) low-grade B-cell lymphomas composed of small cells are uncommon in the tonsil. This is surprising because the tonsil consists of a very intimate intermingled arrangement of epithelium and lymphocytes, which, in theory, would make an ideal environment for the development of MALT lymphomas. In reality, they are so uncommon in this region that they are case reportable.

Metastatic lesions to the tonsil

Although the palatine tonsils are a rich source of lymphatics and lymphoid tissue, metastases to the palatine tonsils are rare. Case reports have described an extraordinarily wide spectrum of malignancies metastatic to this area. Breast, various lung primaries, renal carcinomas, and pancreatic and colorectal malignancies have been reported. Documented cases of Wilms tumor and choriocarcinoma metastasizing to this distant site also exist.

Staging

In addition to cell typing and establishing a differentiation status of the tumor, both accomplished by the pathologist after biopsy, the extent or stage of the tumor is evaluated. Before any prognostication or treatment options are considered, including clinical trial eligibility, the American Joint Committee on Cancer (AJCC) guidelines should be checked through the National Cancer Institute.

To establish the proper stage, the following checklist should be used to ensure that complete information is obtained efficiently:

1. Is the primary tumor occult or has it been located?
2. Is the tumor in situ or invasive?
3. What is the tumor's size?
4. Is there invasion of bone?
5. Is there invasion of the larynx?
6. Is there invasion of muscle, particularly pterygoids; medial and lateral?
7. Is there invasion of the skull base?
8. Is there invasion of the hard palate?
9. Is there invasion of mandible?
10. How is the carotid sheath related to the neoplasm?
11. Is there invasion of the soft tissue of the neck?
12. Is there invasion of the extrinsic tongue muscles?
13. Is there lymph node involvement? If so, is it ipsilateral? Is it contralateral? Is it bilateral? What is the size of the lymph nodes?
14. Are there metastases beyond regional lymph nodes?
15. Are there distant bone metastases?
16. Are there other distant metastases?

The 4 main stages are I, II, III, and IV. Stage IV is subdivided into types A, B, and C.

To obtain as much information as possible prior to therapy, a thorough clinical examination, physical examination, and appropriate imaging studies are necessary.

Plain radiograph films are useful for the study of metastatic disease, especially to the lungs.

CT scans, both with and without contrast, have a role, as does MRI. These are useful in the evaluation of the soft tissue extent of the tumor, as well as the assessment of the lymph node status.

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