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

Fever of unknown origin (FUO) is not infrequently a diagnostic dilemma for clinicians. Common infectious causes include endocarditis and abscesses in adults, and noninfectious causes include neoplasms and certain collagen vascular diseases. Endocrine causes of FUO are rare. The only endocrine disorder likely to present as FUO is subacute thyroiditis. Subacute thyroiditis usually occurs in middle-aged women as viral prodrome, neck tenderness, classic symptoms of thyrotoxicosis, and an elevated erythrocyte sedimentation rate. The patient may have abrupt onset of fever and chills with complaints of thyroid pain, or only low-grade fever with poorly characterized anterior neck pain. We present a case of FUO in a 48-year-old female who had had fever and neck pain for more than one month. Despite an extensive evaluation, the patient had persistent fever and no cause was found, with the exception of subacute thyroiditis. The fever resolved from the second day of treatment with low-dose steroid (prednisolone, 10 mg per day). This case illustrates that subacute thyroiditis should be considered in cases of FUO.
Abscess ; Adult ; Blood Sedimentation ; Chills ; Collagen ; Endocarditis ; Female ; Fever ; Fever of Unknown Origin ; Humans ; Neck ; Neck Pain ; Thyroid Gland ; Thyroiditis, Subacute ; Thyrotoxicosis ; Vascular Diseases

We describe herein an unusual case of subacute thyroiditis presenting as acute psychosis. An 18-year-old male presented at the emergency department due to abnormal behavior, psychomotor agitation, sexual hyperactivity, and a paranoid mental state. Laboratory findings included an erythrocyte sedimentation rate of 36 mm/hr (normal range, 0 to 9), free T4 of 100.0 pmol/L (normal range, 11.5 to 22.7), and thyroid stimulating hormone of 0.018 mU/L (normal range, 0.35 to 5.5). A technetium-99m pertechnetate scan revealed homogeneously reduced activity in the thyroid gland. These results were compatible with subacute thyroiditis, and symptomatic conservative management was initiated. The patient's behavioral abnormalities and painful neck swelling gradually resolved and his thyroid function steadily recovered. Although a primary psychotic disorder should be strongly considered in the differential diagnosis, patients with an abrupt and unusual onset of psychotic symptoms should be screened for thyroid abnormalities. Furthermore, transient thyroiditis should be considered a possible underlying etiology, along with primary hyperthyroidism.
Acute Disease ; Adolescent ; Antipsychotic Agents/therapeutic use ; Humans ; Male ; Psychotic Disorders/diagnosis/drug therapy/*etiology ; Thyroiditis, Subacute/*complications/diagnosis/therapy ; Treatment Outcome