Introduction: Painful Hashimoto's thyroiditis is a rare and atypical form of autoimmune thyroid disease characterized by thyroid pain and tenderness. It can closely resemble subacute thyroiditis and must be distinguished from other causes of thyroid pain, including hemorrhage into a cyst and thyroid abscess. This distinction is particularly important in pregnancy, where radionuclide imaging is not recommended. Case: A 27-year-old pregnant female (G4P3) at 24 weeks’ gestation, with Southeast Asian ovalocytosis and dietcontrolled gestational diabetes, was diagnosed with primary hypothyroidism at 14 weeks following evaluation of a painless goiter. Initial tests showed markedly elevated thyroid-stimulating hormone (>150 mIU/L), low free thyroxine (3.5 pmol/L), and positive anti-thyroid peroxidase antibodies (319 IU/mL), consistent with Hashimoto's thyroiditis. Levothyroxine therapy achieved biochemical euthyroidism. At 24 weeks, she developed acute right-sided anterior neck pain radiating to the ear, with dysphagia, odynophagia, and fever. Examination revealed a tender thyroid without lymphadenopathy. Ultrasound demonstrated diffuse enlargement with bilateral ill-defined hypoechoic avascular areas. Inflammatory markers showed markedly elevated C-reactive protein (184 mg/L) with a normal erythrocyte sedimentation rate (16 mm/h), while thyroid function remained within target range. Imaging and clinical findings made abscess and hemorrhage unlikely. The presence of pre-existing autoimmune thyroid disease, antibody positivity, and hypothyroidism before symptom onset supported painful Hashimoto's thyroiditis over subacute thyroiditis. This case highlights that normal thyroid function tests do not necessarily indicate disease remission, as inflammatory activity may persist independently of hormone levels. Conclusion Painful Hashimoto's thyroiditis should be considered in pregnant patients with known autoimmune thyroid disease presenting with acute thyroid pain despite normal thyroid function. Diagnosis requires integration of clinical, biochemical, and imaging findings to guide appropriate management.
Female ; Pregnancy ; Thyroiditis, Subacute

Introduction: Subacute thyroiditis (SAT) and acute suppurative thyroiditis (AST) are two distinct inflammatory conditions but share many overlapping clinical and biochemical features, which may pose a diagnostic challenge. We report a case of SAT mimicking AST. Case: A 39-year-old female presented with a 3-week history of painful neck swelling and symptoms of thyrotoxicosis, including palpitations, heat intolerance, and diaphoresis. She had no family history of thyroid disease. On examination, she was febrile and had a smooth and tender goiter. Her blood tests showed leukocytosis with elevated erythrocyte sedimentation rate and C-reactive protein. Her thyroid function test (TFT) showed thyroid-stimulating hormone of 0.023 mIU/L and free thyroxine 4 of 32.15 pmol/L. An urgent ultrasound revealed a large, ill-defined heterogeneously hypoechoic lesion predominantly at the left lobe of the thyroid gland with mild intralesional vascularity. These were reported as features of thyroiditis with infective or early suppurative changes. Fine needle aspiration (FNA) of the lesion was attempted by the radiologist but was unsuccessful. She was treated with intravenous antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs), but symptoms persisted. Repeated ultrasound and computed tomography scans about 1 week later confirmed an enlarged thyroid gland with no obvious lesion or collection within the gland. The diagnosis was revised to SAT, and prednisolone 15 mg OD was started. This resulted in rapid improvement in her symptoms and inflammatory markers. Four weeks later, she remained asymptomatic, and prednisolone was gradually tapered off. Serial TFT monitoring showed a classic triphasic pattern with an initial hyperthyroid phase, followed by hypothyroidism before returning to euthyroidism. Conclusion SAT can present with a focal lesion on the ultrasound during the early stage of the disease, making it difficult to distinguish from a thyroid abscess due to overlapping features. Good clinical judgement guided by FNA and appropriate follow-up imaging may be helpful in differentiating between the two conditions.
Thyroiditis, Subacute ; Thyroiditis, Suppurative

F-18 fluorodeoxyglucose (FDG) is a highly influential radiotracer that provides valuable information in many cancer types. However, the normal biodistribution of F-18 FDG is often variable and can be altered by intrinsic or iatrogenic factors. We report a case of diffuse symmetrically increased skeletal muscle uptake and relatively decreased hepatic uptake on F-18 FDG PET/CT in a 57-year-old female with pulmonary adenocarcinoma. Detailed clinical evaluation and retrospective radiologic evaluation revealed that she had been diagnosed with subacute thyroiditis 2 weeks ago. After 6 weeks, F-18 FDG distribution was normalized at the follow-up PET/CT study.
Adenocarcinoma ; Female ; Follow-Up Studies ; Humans ; Hyperthyroidism ; Middle Aged ; Muscle, Skeletal ; Positron-Emission Tomography and Computed Tomography ; Retrospective Studies ; Thyroiditis, Subacute

Riedel's thyroiditis is a rare fibrotic condition that results in the destruction of the thyroid and infiltration into surrounding tissues. The exact etiology is not yet clear, although systemic fibrosing disorder, a variant of Hashimoto's thyroiditis, a primary inflammatory disorder of the thyroid, and even a manifestation of end-stage subacute thyroiditis has been suggested. Although various treatments have been applied, no definitive treatment has yet been established. We report a case of Riedel's thyroiditis treated without complications using microscopic surgery. A 54-year-old man visited our clinic presenting with neck tightness and a left neck mass. A gun biopsy revealed a benign thyroid mass, although the radiologic findings showed a malignant thyroid tumor with invasion into the trachea and strap muscles. The patient underwent a left hemi-thyroidectomy and shaving of the trachea, esophagus and recurrent laryngeal nerve under microscopy. The final pathology revealed Riedel's thyroiditis combined with Hashimoto's thyroiditis. The patient had symptomatic relief without vocal fold paralysis and hypocalcemia. Surgical treatment using microscopic dissection can be considered to be one of treatment option for Riedel's thyroiditis.
Biopsy ; Esophagus ; Humans ; Hypocalcemia ; Microscopy ; Microsurgery ; Middle Aged ; Muscles ; Neck ; Paralysis ; Pathology ; Recurrent Laryngeal Nerve ; Thyroid Gland* ; Thyroiditis* ; Thyroiditis, Subacute ; Trachea ; Vocal Cords

PURPOSE: Although Sjögren's syndrome (SS) is the most common disease causing xerostomia, autoimmune thyroid diseases can also affect the salivary glands. The aim of our study was to estimate the prevalence of thyroid diseases (TD) in subjects with symptoms of xerostomia and evaluate the efficacy of salivary gland scintigraphy (SGS) in the detection of TD in patients with SS and without SS.METHODS: We retrospectively reviewed the SGS findings of 173 subjects (men:women, 29:144) with symptoms of xerostomia. Ejection fractions (EF) in the parotid and submandibular glands were calculated. Thyroid disease was diagnosed on the basis of the results of the visual assessment of tracer uptake in the thyroid gland on SGS images as well as serological thyroid function tests.RESULTS: Based on the American-European Criteria, 94 patients were diagnosed with SS. Hashimoto's thyroiditis was diagnosed in 63 patients, subacute thyroiditis in 23, subclinical hypothyroidism in five, and Graves' disease in one. There were significant differences in the EF values of the parotid and submandibular glands between patients with TD and those with undetermined diagnoses.CONCLUSIONS: More than half of patients with xerostomia exhibited TD. Thyroid assessment by SGS is feasible, and SGS appears to be useful for the patients with xerostomia caused by TD. SGS may be the first imaging modality capable of evaluating both salivary gland function and thyroid gland status in patients with xerostomia. This strategy would make the requirement for additional workup for thyroid disease.
Diagnosis ; Graves Disease ; Humans ; Hypothyroidism ; Prevalence ; Radionuclide Imaging ; Retrospective Studies ; Salivary Glands ; Submandibular Gland ; Thyroid Diseases ; Thyroid Function Tests ; Thyroid Gland ; Thyroiditis ; Thyroiditis, Subacute ; Xerostomia

BACKGROUND AND OBJECTIVES: In the past, subacute thyroiditis causing thyrotoxicosis included both painful and painless subgroup, but it is representative for the painful subacute thyroiditis these days. So we evaluated the clinical and laboratory characteristics of subacute thyroiditis and compared with the painless (silent) thyroiditis, and identified predictive factors of permanent hypothyroidism and recurrence. MATERIALS AND METHODS: This was a retrospective case series study analyzing clinical data of 221 consecutive patients diagnosed between 2009 and 2015. Medical records were reviewed for diagnostic route, age distribution, laboratory data, clinical course and long-term follow up outcome. RESULTS: The mean age was 48 years; female v/s male ratio 3.4:1. Median disease duration was 110 days; mean peak free T4 level was 2.9 ng/dL. 56.7% of painless thyroiditis patients were diagnosed on health checkup or routine thyroid function test with symptoms not typically associated with thyrotoxicosis. Permanent hypothyroidism was not uncommon (11/221; 5.0%). Higher peak thyroid-stimulating hormone (TSH) was associated with permanent hypothyroidism in painless thyroiditis. Lower peak TSH was associated with recurrence rate in both subacute and painless thyroiditis. In painless thyroiditis, short duration of thyrotoxicosis phase was also associated with recurrence rate. CONCLUSION: Considerable numbers of painless thyroiditis without symptoms were diagnosed on health checkup. Higher peak TSH was associated with permanent hypothyroidism in painless thyroiditis. Recurrence rate was related with lower peak TSH in both groups.
Age Distribution ; Female ; Follow-Up Studies ; Humans ; Hypothyroidism ; Male ; Medical Records ; Postpartum Thyroiditis ; Recurrence ; Retrospective Studies ; Thyroid Function Tests ; Thyroid Gland* ; Thyroiditis* ; Thyroiditis, Subacute* ; Thyrotoxicosis ; Thyrotropin

BACKGROUND AND OBJECTIVES: In the past, subacute thyroiditis causing thyrotoxicosis included both painful and painless subgroup, but it is representative for the painful subacute thyroiditis these days. So we evaluated the clinical and laboratory characteristics of subacute thyroiditis and compared with the painless (silent) thyroiditis, and identified predictive factors of permanent hypothyroidism and recurrence. MATERIALS AND METHODS: This was a retrospective case series study analyzing clinical data of 221 consecutive patients diagnosed between 2009 and 2015. Medical records were reviewed for diagnostic route, age distribution, laboratory data, clinical course and long-term follow up outcome. RESULTS: The mean age was 48 years; female v/s male ratio 3.4:1. Median disease duration was 110 days; mean peak free T4 level was 2.9 ng/dL. 56.7% of painless thyroiditis patients were diagnosed on health checkup or routine thyroid function test with symptoms not typically associated with thyrotoxicosis. Permanent hypothyroidism was not uncommon (11/221; 5.0%). Higher peak thyroid-stimulating hormone (TSH) was associated with permanent hypothyroidism in painless thyroiditis. Lower peak TSH was associated with recurrence rate in both subacute and painless thyroiditis. In painless thyroiditis, short duration of thyrotoxicosis phase was also associated with recurrence rate. CONCLUSION: Considerable numbers of painless thyroiditis without symptoms were diagnosed on health checkup. Higher peak TSH was associated with permanent hypothyroidism in painless thyroiditis. Recurrence rate was related with lower peak TSH in both groups.
Age Distribution ; Female ; Follow-Up Studies ; Humans ; Hypothyroidism ; Male ; Medical Records ; Postpartum Thyroiditis ; Recurrence ; Retrospective Studies ; Thyroid Function Tests ; Thyroid Gland* ; Thyroiditis* ; Thyroiditis, Subacute* ; Thyrotoxicosis ; Thyrotropin

Graves' disease following subacute thyroiditis is uncommon. Some patients in these cases showed positive for thyroid antibody only transiently in the resolving phase. However, Graves' disease can rarely be caused by the presence of antibodies after subacute thyroiditis, although the pathophysiology of this is unclear. A 40-year-old woman presented with anterior neck pain and swallowing difficulty. Thyroid function testing showed reduced thyroid-stimulating hormone (TSH) and elevated free thyroxine levels. A thyroid scan revealed decreased uptake in the bilateral thyroid gland. The patient was initially diagnosed with subacute thyroiditis and treated with steroids. Five months later, thyroid function testing showed recurrent hyperthyroidism with positive conversion of TSH receptor antibody, indicating Graves' disease. Since then, she needed the long-term methimazole treatment. In summary, we herein report a case of Graves' disease occurring after subacute thyroiditis.
Adult ; Antibodies ; Deglutition ; Female ; Graves Disease* ; Humans ; Hyperthyroidism ; Immunoglobulins, Thyroid-Stimulating ; Methimazole ; Neck Pain ; Receptors, Thyrotropin ; Steroids ; Thyroid Function Tests ; Thyroid Gland ; Thyroiditis, Subacute* ; Thyrotropin ; Thyroxine

OBJECTIVE: To report the clinical characteristics and outcomes of subacute thyroiditis (SAT) patients at the Theptarin Hospital Thyroid Clinic. Methodology. A retrospective review of medical records of SAT patients in the Theptarin Hospital from January 2007 to December 2013 was conducted. Clinical characteristics, laboratory findings, modes of treatment and complications were recorded.

RESULTS: From January 2007 to December 2013, SAT was diagnosed in 149 patients, with the occurrence of SAT peaking in October and November. Of 115 patients who had complete follow-up data, mean age was 43.8±10.8 years, 88.7% were women, and SAT was preceded by an upper respiratory tract infection in 68.7%. Oral prednisolone was given in 83 cases (72.2%) at a median starting dose of 30 mg/day and was continued for a median duration of 49 days. Recurrence of SAT during the tapering period of oral prednisolone was observed in 12% of patients, resulting in reinitiation of steroid in 13% of patients for late recurrence. Transient and permanent hypothyroidism developed in 6.1% and 8.7% of patients respectively.

CONCLUSIONS: SAT in Thai patients showed seasonal clustering during October and November. Recurrences of SAT were common in the course of steroid treatment. SAT patients require careful follow-up during steroid treatment and long-term surveillance for thyroid dysfunction.
Thyroiditis, Subacute

The occurrence of Graves' disease following subacute thyroiditis (SAT) is rare. The pathophysiology of it is not well known. We report a case of Graves' disease following SAT presented with creeping. A 45-year-old woman presented with neck pain, and thyrotoxic symptoms. Neck pain migrated from left lobe to right lobe of the thyroid. Thyroid scan revealed decreased uptake in the both lobes except the superior portion of the right thyroid gland. Initially, the patient was diagnosed with SAT and treated with steroid therapy. Four months later, thyroid function test showed suppressed thyroid-stimulating hormone (TSH), elevated free thyroxine (T4) and TSH receptor antibody. Thyroid scan revealed increased uptake compatible with Graves' disease. The autoimmune alteration after SAT may lead to the development of Graves' disease in the susceptible patients. These patients should be monitored for the development of Graves' disease.
Female ; Graves Disease* ; Humans ; Middle Aged ; Neck Pain ; Receptors, Thyrotropin ; Thyroid Function Tests ; Thyroid Gland ; Thyroiditis, Subacute* ; Thyrotropin ; Thyroxine