NYU Medical Grand Rounds Clinical Vignette

1. NYU Medical Grand Rounds Clinical Vignette Arnab Ghosh, MD PGY-2 10/23/12 UNITED STATES DEPARTMENT OF VETERANS AFFAIRS

2. Chief Complaint UNITED STATES DEPARTMENT OF VETERANS AFFAIRS The patient is a 67 year old male who presented to his primary care physician with palpitations.

3. History of Present Illness UNITED STATES DEPARTMENT OF VETERANS AFFAIRS • When reviewed in clinic by his primary physician, he appeared clinically euthyroid although he did have evidence of an enlarged thyroid gland on examination by his primary care physician. • He was referred to an endocrinologist.

4. Additional History UNITED STATES DEPARTMENT OF VETERANS AFFAIRS • Past Medical History: Nil • Past Surgical History: Nil • Social History: Works as a dentist, occasional social drinker, non smoker, nil illicit drug use • Family History: Nil family history of thyroid disease • Medications: Nil

5. Physical Examination UNITED STATES DEPARTMENT OF VETERANS AFFAIRS • General: He appeared well • Thyroid Examination: a palpable thyroid approximately one and a half times the normal size • Nil evidence of tenderness, dominant nodules nor lymphadenopathy • Nil peripheral stigmata of thyroid disease • Remainder of Physical Exam was normal

6. Laboratory Findings UNITED STATES DEPARTMENT OF VETERANS AFFAIRS • CBC: within normal limits • Basic Metabolic panel: within normal limits • Hepatic panel: within normal limits • Thyroid Stimulating Hormone (TSH) • 2.7 miU/L (N:0.4-4.0 mIU/L) • T4 5.9 mcg/dL (N: 4.8-11.0 mcg/dL) • T3 0.78 ng/mL (N:0.8-1.7 ng/mL) • Anti-thyroglobulin antibody: 2.4 U/mL (>1.0 U/mL – positive) • Anti-thyroperoxidase antibody:14.0 U/mL (>1 U/mL – positive)

7. Other Studies UNITED STATES DEPARTMENT OF VETERANS AFFAIRS • ECG: normal sinus rhythm with occasional premature ventricular contractions • Thyroid Ultrasound: • 1.7x1.1cm nodule in the R lobe (hypoechoic) • 9x11mm nodule in R lobe (hypoechoic) • Nil microcalcifications, nil increased vascularity • Fine Needle Aspiration performed of larger nodule: • Colloid in a population of lymphocytes

8. UNITED STATES DEPARTMENT OF VETERANS AFFAIRS Working Diagnosis Euthyroid lymphocytic thyroiditis

9. UNITED STATES DEPARTMENT OF VETERANS AFFAIRS Outpatient Course • The patient was referred back to his primary care physician, who intermittently checked TSH levels, which remained normal • 8 years later, the patient was referred back to his endocrinologist with a TSH measured at 4.16 mIU/L (N:0.4-4.0mIU/L) • Patient was clinically euthyroid during this time

10. UNITED STATES DEPARTMENT OF VETERANS AFFAIRS Outpatient Course • On repeat labs by the endocrinologist, the TSH was measured 11.4 mIU/L • Other laboratory values of note: • T4 6.3 mcg/dL (N: 4.8 - 11.0 mcg/dL) • T3 Uptake 31.7% (N: 23.5 - 40.6%) • Free thyroid index 4.0 (N: 1.5 - 3.8) • Anti-thyroperoxidase antibody: 239 IU/mL (normal < 27 iU/mL) • Anti-Thyroglobulin antibody: < 20 IU/mL (normal)

11. UNITED STATES DEPARTMENT OF VETERANS AFFAIRS Outpatient Course • Repeat Thyroid Ultrasound performed: Coarsely and diffusely multinodular Mild hyperaemia of the entire thyroid R lobe: 2 solid hypoechoic nodules, 15x10mm and 9x9mm L inferior lobe: 8x6mm nodule Nil calcifications • Fine Needle Aspiration of 3 nodules: R and L nodules: colloid with lymphocyte background L inferior lower lobe: colloid accumulation

12. UNITED STATES DEPARTMENT OF VETERANS AFFAIRS Outpatient Course The patient was started on Levothyroxine 25 μmcg daily by mouth

13. UNITED STATES DEPARTMENT OF VETERANS AFFAIRS Outpatient Course Repeat lab values 3 months later in clinic • TSH 2.74 miU/L (N:0.4-4.0 mIU/L) • T4 5.7 mcg/dL (N: 4.8 - 11.0 mcg/dL) • T3 Uptake 33.9% (N: 23.5 - 40.6%) • Free thyroid index 1.9 (N: 1.5 - 3.8)

14. UNITED STATES DEPARTMENT OF VETERANS AFFAIRS Final Diagnosis Hashimoto’s thyroiditis (with failing thyroid)