Usefulness of endoscopic ultrasonography (EUS) in diagnosing esophageal infiltration of thyroid cancer

The surgical management of locally advanced well-differentiated thyroid carcinoma: changes over the years according to the AJCC 8th edition Cancer Staging Manual

Background

Well-differentiated thyroid carcinoma is defined as locally advanced in the presence of an extra thyroid extension, e.g., when the surrounding structures such as the trachea, larynx, esophagus and main blood vessels are invaded by cancer. The 8th edition AJCC Cancer Staging Manual states that this is the main characteristic to evaluate for the staging and consequently for the prognosis in patients over 55 years old.

Main body

Distinguishing different forms of locally advanced thyroid cancer is essential, and the various anatomical structures and the clinical and therapeutic consequences must be taken into account. An accurate diagnosis of the organs invaded by thyroid cancer is necessary for the planning of surgical treatment, and both aspects are crucial to improving the patients’ survival. Patients affected by thyroid cancer with extra thyroid extension have a poor prognosis and the removal of the entire neoplasm represents a key factor for better disease-free survival.

Conclusions

We discuss the changes introduced by the 8th edition AJCC Cancer Staging Manual, in terms of the diagnostic and surgical management of extra thyroid extension, in patients affected by papillary and follicular thyroid cancer.

Metastatic Renal Cell Cancer to Thyroid Diagnosed by Endoscopic Ultrasound Guided Fine Needle Aspiration Technique

Medical literature about the role of endoscopic ultrasound (EUS) in identifying thyroid lesions is limited. We present a case of secondary thyroid cancer from renal cell carcinoma (RCC) metastasis, diagnosed by thyroid EUS-fine needle aspiration (FNA) approach that was done for staging of esophageal adenocarcinoma, in a patient with 11-year history of complete right nephrectomy for RCC. An 81-year-old female patient underwent EUS for the evaluation of a newly discovered distal esophageal cancer. A hypoechoic, round, and well-demarcated mass that measured 26.9 mm × 21.9 mm was noticed in the right lobe thyroid gland. Therefore FNA was performed. The cytological results were consistent with metastatic RCC. In conclusion, EUS-FNA of thyroid nodule is a feasible and safe technique that can be used to evaluate any suspicious thyroid nodule. This case emphasizes the importance of carefully examining the thyroid gland during routine upper esophageal EUS examinations in the presence of history of nonthyroidal cancer.

Endosonographic examination of thyroid gland among patients with nonthyroid cancers

Objectives:

There is limited endosonographic literature regarding thyroid gland pathology, which is frequently visualized during upper endoscopic ultrasound (EUS). Our objective was to assess the prevalence of benign and malignant thyroid lesions encountered during routine upper EUS within a cancer center setting.

Materials and Methods:

The data were prospectively collected and retrospectively analyzed. All upper EUS procedures performed between October 2012 and July 2014 were reviewed at a large referral cancer center. Data collected included patient demographics, preexisting thyroid conditions, thyroid gland dimensions, the presence or absence of thyroid lesions, and EUS morphology of lesions if present, and interventions performed to characterize thyroid lesions and pathology results when applicable.

Results:

Two hundred and forty-five EUS procedures were reviewed. Of these, 100 cases reported a detailed endosonographic examination of the thyroid gland. Most of the thyroid glands were endosonographically visualized when the tip of the scope was at 18 cm from the incisors. Twelve cases showed thyroid lesions, out of which three previously undiagnosed thyroid cancers were visualized during EUS (two primary papillary thyroid cancers and one anaplastic thyroid cancer). Transesophageal EUS-guided fine needle aspiration of thyroid lesions was feasible when the lesion was in the inferior portion of the thyroid gland, and the tip of the scope was at 18 cm or more from the incisors.

Conclusions:

Routine EUS examination may detect unexpected thyroid lesions including malignant ones. We encourage endosonographers to screen the visualized portions of the thyroid gland during routine withdrawal of the echoendoscope.

Thymic carcinoma diagnosed by using endoscopic ultrasound with fine-needle aspiration

There is a paucity of literature on the use of endoscopic ultrasound (EUS) for evaluating superior mediastinal structures, especially the thymus gland. We report a case of thymic carcinoma diagnosed by using EUS elastography with strain ratio and fine-needle aspiration (FNA). A 64-year-old woman presented with altered mental status and was diagnosed with autoimmune encephalitis. Further work-up suggested a superior mediastinal mass, for which she underwent EUS. A hypoechoic mass was found in the superior mediastinum at the level of the aortic arch. Real-time EUS elastography showed a predominantly blue hue to the mass concerning for malignancy. FNA of the mass was performed, which revealed numerous large neoplastic cells under a background of a small lymphoid infiltrate. Immunohistochemistry was strongly positive for PAX8, pancytokeratin, and CAM5.2. The pathologic and immunohistochemical stains were consistent with thymic carcinoma.

Primary papillary thyroid carcinoma diagnosed by using endoscopic ultrasound with fine needle aspiration

There is paucity in the literature on the use of endoscopic ultrasound (EUS) for evaluating the thyroid gland. We report the first case of primary papillary thyroid cancer diagnosed by using EUS and fine needle aspiration (FNA). A 66-year-old man underwent EUS for the evaluation of mediastinal lymphadenopathy. FNA of the lymph nodes showed benign findings. A hypoechoic mass was noted in the right lobe of the thyroid gland. Therefore, FNA was performed. The cytological results were consistent with primary papillary thyroid cancer.

The oncocyte that went places: diagnosis with EUS-guided FNA

Although uncommon, Hurthle cell neoplasms have a characteristic histologic and cytologic features which often aid in the diagnosis of these lesions. In fine needle aspiration biopsies, determining malignant potential on cytologic features is challenging unless other evidence of malignancy (such as metastases) are known. The role of EUS-guided FNA in diagnosing superior mediastinal masses has been described previously. It's role in evaluating subcarinal metastases from lung cancer primaries have also heen studied. However we describe metastatic thyroid Hurthle cell carcinoma to the subcarina diagnosed through EUS-guided FNA combining the unique cytologic features o Hurthle cell neoplasms and the versatility ofthe endoscopic ultrasound to reach a diagnosis in this unusual neoplasm.

Locally advanced thyroid cancer: can CT help in prediction of extrathyroidal invasion to adjacent structures?

OBJECTIVE

The purpose of this study was to determine the diagnostic accuracy of CT for detecting extrathyroidal invasion of thyroid cancer to adjacent structures.

MATERIALS AND METHODS

Eighty-four patients (19 men, 65 women; age range, 19-84 years; mean, 54.2 +/- 15.4 years) with 86 malignant tumors of the thyroid with extracapsular extension (37 T3, 49 T4) were retrospectively enrolled in this study. Two radiologists independently evaluated the CT findings of invasion of thyroid cancer into the trachea, esophagus, common carotid artery, internal jugular vein, and recurrent laryngeal nerve. These results were compared with the surgical and histopathologic findings.

RESULTS

The mean sensitivity, specificity, and accuracy of CT were as follows: 59.1%, 91.4%, and 83.2% for tracheal invasion; 28.6%, 96.2%, and 90.7% for esophageal invasion; 75.0%, 99.4%, and 98.8% for invasion of the common carotid artery; 33.3%, 98.8%, and 97.1% for invasion of the internal jugular vein; and 78.2%, 89.8%, and 85.5% for invasion to the recurrent laryngeal nerve. Interobserver agreement was moderate to good in the five categories of extrathyroidal invasion with a mean kappa value of 0.65 (range, 0.49-0.77).

CONCLUSION

Although the effectiveness is limited by low sensitivity, CT may be a valuable tool for evaluation of extrathyroidal invasion of thyroid cancer to adjacent structures.