Witt Thyroid Cancer: Current Diagnosis, Management, and Prognostication, An Issue of Otolaryngologic Clinics of North America

1. Auflage 2014
ISBN: 978-0-323-32040-5
Verlag: Elsevier HealthScience EN
Format: EPUB
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, Band Volume 47-4, 100 Seiten

Reihe: The Clinics: Internal Medicine

This Otolaryngologic Clinics' publication's intent is to provide standard and state of the art clinician performed thyroid ultrasound and ultrasound guided FNA technique. The subject area is evolving rapidly with new technologies being incorporated. This title integrates thyroid cytology, FNA and Ultrasound Guided FNA with inclusion of diagnostic molecular testing. Clinical Thyroid Molecular Testing has ushered in a new era to the diagnosis, management and prognostication of thyroid nodules. The discussion of this highly clinically applicable subject is described in terms of diagnostic process. This is a thyroid neoplasm clinical 'game changer” for the General Otolaryngologist, Head and Neck Surgeon, General Surgeon, Endocrinologist, Pathologist, and Radiologist. This testing maximizes the number of patients who have cancer to receive the correct therapeutic surgery appropriately and minimizes the number of patients who do not need surgery (and avoid the potential complications and surgery) because they do not have cancer. Surgical management and prognostication have far reaching implications with fine needle aspiration driven molecular markers. Some topics include: Clinical evaluation of the thyroid nodule; Thyroid cytology; Clinician performed thyroid ultrasound; Clinician performed thyroid ultrasound guided FNA; Thyroid cancer molecular laterations - what the surgeon should know; Thyroid cancer multi-gene expression - what the surgeon needs to know; Incorporating molecular testing into your thyroid practice - five experts discuss; and others.

Autoren/Hrsg.

Witt, Robert L.

Leseproben

Evidence-Based Evaluation of the Thyroid Nodule
Louise Davies, MD, MSabc*[e-mail] and Gregory Randolph, MDde,     aDepartment of Veterans Affairs Medical Center, VA Outcomes Group, 111B, 215 North Main Street, White River Junction, VT 05009, USA; bSection of Otolaryngology, Geisel School of Medicine at Dartmouth, Rope Ferry Road, Hanover, NH 03755, USA; cThe Dartmouth Institute for Health Policy and Clinical Practice, 35 Centerra Parkway, Lebanon, NH 03766, USA; dDivision of Thyroid and Parathyroid Surgery, Department Otology and Laryngology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA; eDivision of Surgical Oncology, Massachusetts General Hospital, 55 Fuit Street, Boston, MA 02114, USA *Corresponding author. VA Outcomes Group, 111B, 215 North Main Street, White River Junction, VT 05009. This article reviews the most current literature on thyroid nodule evaluation, with particular attention to the problem of the incidentally identified thyroid nodule. Although traditional risk factors for thyroid cancer, such as age, gender, and familial syndromes, are still important, the manner in which a thyroid nodule comes to attention is of great importance these days when considering how to proceed in a workup. Most thyroid nodules today are discovered through radiologic imaging tests performed for other reasons. This article covers the key considerations that are vital in balancing the risks and benefits of thyroid nodule workup and treatment. Keywords Thyroid Thyroid nodule Thyroid cancer Evaluation Thyroid neoplasm risk Key points
• Thyroid nodules are extraordinarily common; by age 90, virtually everyone has nodules. • Ultrasound is the most valuable imaging study for making decisions about which nodules to biopsy. • Nodules that are greater than 2 cm in size, that are entirely solid in composition, and that have microcalcifications are most likely to harbor a cancer. • Molecular markers can help predict the presence of malignancy in cytologically indeterminate nodules, but markers do not accurately predict aggressiveness of cancers. • Small papillary thyroid cancers can be safely observed in selected patients; discussions with patients should incorporate this option. The thyroid nodule—scope of the problem
Thyroid nodules are extraordinarily common. A key challenge for clinicians is to decide which ones require evaluation and intervention. Half of people age 50 or over with clinically normal thyroid glands and thyroid function have thyroid nodules, and by age 90, virtually everyone has nodules.1 Thyroid cancer is commonly found at autopsy in individuals who have died of other causes, never having been detected in that patient’s life. Estimates of cancer prevalence at autopsy are quite variable and depend largely on the method used to detect the cancers and geographic location, but range from a low of about 4% to a high of 36%.1–5 Thus, thyroid cancers can be clinically insignificant for many patients. The workup and treatment can potentially expose the patient to the risks of treatment without the likelihood of any benefit. This challenging aspect of thyroid nodules has been recognized for some time, but the problem has been compounded in recent years by advances in and proliferation of imaging technology. Advanced radiologic imaging rates (computed tomography [CT], magnetic resonance imaging [MRI], nuclear medicine, and ultrasound) have increased 3-fold since 1996.6 These scans commonly reveal small, nonpalpable thyroid nodules, which in the past would never have been identified because they were too small to detect by palpation, and too small to cause symptoms to the patient. Because so many of these incidental thyroid findings are now being uncovered, a dramatic increase in the observed incidence of small thyroid cancers is being experienced.7,8 The increase in thyroid cancer incidence caused by this phenomenon is a problem for several reasons. First, patients are exposed to harm from what is ultimately unnecessary treatment. Second, these incidental findings unnecessarily create “patients with cancer” with all the attendant anxiety, surveillance needs, and financial ramifications.9 Last, these patients affect the validity of studies designed to understand and mitigate the risks of death or recurrence from thyroid cancer by serving to falsely improve the results of clinical trials. With this in mind, the chief challenge to clinicians today is deciding which nodules require workup, and how aggressively to treat them. What follows is a review of the current evidence related to the approach to the patient with a nodule. Patient presentation
When a patient comes to the office with a thyroid nodule, the mechanism of detection is of paramount importance and will determine what next steps should be taken (Fig. 1). A patient who presents with symptoms of tracheal or esophageal compression should raise concern for a malignancy, although large goiter and Hashimoto thyroiditis can also cause these types of symptoms. The clinician should inquire regarding symptoms related to change in ease of breathing, swallowing, and speech quality. In contrast, a mass that was first noticed by the patient but that is not otherwise causing symptoms will have a much broader differential diagnosis (Table 1). Although a rapid increase in size can signal malignancy, it can also signal hemorrhage into a benign neoplasm. Table 1 Differential diagnosis of the thyroid nodule Multinodular goiter
Hashimoto thyroidtis
Simple or hemorrhagic cyst
Follicular adenoma
Subacute thyroiditis Papillary carcinoma (88%) Follicular carcinoma (9%) Hurthle cell (oxyphilic) type Medullary carcinoma (<2%) Anaplastic (<2%) Primary thyroid lymphoma (rare) Metastases from breast, renal cell, others (rare)
Fig. 1 Thyroid nodule evaluation algorithm based on current best available evidence. a See Box 1, Table 2 for risk assessment details. b See Table 3 for interpretation and recommendations for action based on FNA results. US, ultrasound. Today, many thyroid nodules come to attention through radiologic imaging studies. The nodules are subclinical—not causing any symptoms for the patient and generally not apparent on the physical examination. There are 2 main pathways of such radiologic detection—the first is through incidental detection on radiologic imaging studies done for other reasons, such as chest CT (obtained for cough, for example), neck MRI (performed after motor vehicle accident/suspected whiplash injury, for example), or carotid ultrasound. The second pathway is detection through a “diagnostic cascade” of nontargeted and sometimes inappropriate initial testing—for example, when a thyroid ultrasound is inappropriately ordered as part of a more general workup for weight gain, fatigue, or hair loss—and a thyroid nodule is found but is unrelated to the patient’s presenting symptoms.8 There are emerging data suggesting that traditional thyroid cancer risk factors, such as age, may be different for subclinical nodules that turn out to be papillary thyroid cancer on evaluation than for clinically apparent cancers, so obtaining a complete history is of even greater importance than in the past.10 On physical examination, a mass that is hard and fixed may indicate malignancy, but a mass may also be hard in patients with Hashimoto thyroiditis. The presence of palpable adenopathy should raise suspicions of malignancy. Lymph nodes may be biopsied if radiographically indeterminate as part of the initial workup. Assessment of risk factors
Traditional risk factors for thyroid cancer in a thyroid nodule include age, gender, history of radiation exposure, family history of thyroid cancer, and cancer syndromes. Data refining the significance of these risks continue to evolve (Box 1).11 Box 1   Risk factors for malignancy in a thyroid nodule Risk factors Symptoms Persistent hoarseness, dysphagia, or dysphonia Lump is growing History Radiation exposure before age 20: Therapeutic irradiation Advanced medical imaging (eg, CT scan/PET scan) Family...