Resistant thyrotoxicosis: A case of sarcoidosis of thyroid
A 37-year-old male presented with weight loss, heat intolerance, excessive sweating, and palpitations of 6 months duration. Clinically, he was anxious, had tachycardia, brisk reflexes, and tremors. Thyroid profile revealed T3 2.58 ng/ml, T4 21.41 μg/dl, and TSH 0.02 mIU/L. Both lobes of thyroid were diffusely enlarged (measuring 5 × 2 cm) on USG. 99mTechnetium scan has shown uniformly increased uptake (36%). TSH receptor antibodies and anti-TPO antibodies were negative.\nHe was incidentally found to have bilateral hilar lymphadenopathy on chest X-ray []. Clinically, the patient was revaluated and was found to have no peripheral lymphadenopathy or any respiratory abnormality. Examination of the respiratory system was unremarkable. No evidence of involvement of skin, eyes, or central nervous system was present. Montoux test and interferon gamma release assay were normal and sputum examination was negative for AFB by ZN stain. There was a fall of ESR by 8 mm in first hour. CECT chest done has revealed multiple homogenously enhancing enlarged lymph nodes [] in the mediastenum (maximum size 24 mm) and multiple well-defined nodules (2-4 mm in size) in perilymphatic distribution [Figure and ]. Spirometry was normal, and diffusion/lung volumes were normal. Serum ACE was 106.0 IU/L (normal <60 IU/L). Ultrasound abdomen was normal and serum calcium was 8.9 mg/dl. 24-hour urinary calcium excretion was 3.96 g/day. Fiber optic bronchoscopy and transbronchial lung biopsy from right lower lobe superior segment was done. Histopathological examination revealed noncaseating granulomas consistent with sarcoidosis [Figure -]. Based on these, an impression of Graves’ disease with sarcoidosis stage II was made. As he did not have any functional disability or vital organ involvement, no active treatment was contemplated for sarcoidosis at this juncture and was advised regular follow-up.\nPatient underwent radioablation with 29 mCiof 131I after initial trial of antithyroids for 2 years. In view of persistent clinical and hormonal profile of thyrotoxicosis, repeat dose of 26 mCiof 131I was given 8 months later. The patient was kept under follow-up. However, symptoms persisted and hormonal profile continued to show hyperfunctioning thyroid gland. Repeat thyroid profile revealed T3 1.82 ng/ml, T4 22.9 μg/dl, and TSH 0.03 mIU/L. Thus, a possibility of thyroid sarcoidosis was considered in which the clinical features of toxicosis may be refractory to antithyroids and radioablation. Patient was subjected to FNAC thyroid which revealed ill-formed elements of granulomatous tissue. Patient refused to undergo the biopsy of the thyroid gland. He was subjected to PET scan which revealed increased uptake in liver, spleen, and thyroid with “Lambda” and “Panda” sign [].\nPatient was given a trial with steroids (oral prednisolone at 1 mg/kg) and patient achieved euthyroidism 3 months after steroid therapy. Steroid therapy was gradually tapered over 6 months period. Patient persisted to be euthyroid on 1 year follow-up. Temporal profile of the thyroid status and various modalities of therapy are depicted in .