Primary Care Otolaryngology

Thyroid Cancer

decision for resection more challenging. An FNAB diagnosis of malignant cells, however, is an obvious indication for surgery, either a total thyroid lobectomy or a total thyroidectomy. Certainly, any evidence of thyroid can- cer in the neck nodes is an indication for total thyroidectomy and appropri- ate neck dissection. Remember, that absent any risk factors, there is a high degree of probabil- ity that the nodule is benign. If the pathologic interpretation on the FNAB favors a benign histopathology and the patient does not have any other risk factors for thyroid cancer, one can advocate observation. If the lab report is indeterminant or inconclusive, a repeat FNAB with the aid of an ultrasound is necessary to ensure sampling efficiency of the tissue. When multiple nodules are found, the thyroid is classified as a multinodular thyroid or goiter, and only the dominant or largest nodules are biopsied. If a single nodule is determined to be inconclusive by FNAB, FNAB should be repeated. Radionuclide thyroid scans have become less essential to the diagnostic workup of nodules with the development and refinement of ultrasound and fine-needle aspiration techniques. Forms of Thyroid Cancer There are two essential classifications of thyroid cancer: well differentiated and other. The more common forms of thyroid cancer are well differen- tiated, and include papillary and follicular (including the Hürthle cell variant). The “other” category includes less well-differentiated forms of thyroid cancer, including medullary, and anaplastic. Lymphoma may Approximately 80 percent of thyroid cancers are papillary histologically. These may have a follicular component, but any amount of papillary com- ponent means the tumor will behave more like a papillary tumor. These tumors can be multifocal in the gland and often metastasize to neck lymph nodes. The presence of lymph node masses does not appear to affect sur- vival rates. Histologically, they have clear nuclei (“Orphan Annie” cells ), and may have psammoma bodies. Factors predictive of a better prognosis include small size (less than 1.5 centimeters (cm)) and absence of thyroid gland capsule involvement. For unknown reasons, this disease follows a much more indolent course when discovered in people under age 40. How- ever, while papillary carcinoma patients under 40 years of age ultimately live longer, they also experience a higher rate of recurrence. also arise in the thyroid. Papillary Carcinoma

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