Subacute thyroiditis

Subacute Thyroiditis—Still a Diagnostic Challenge: Data from an Observational Study

Background: Subacute thyroiditis (SAT) is a relatively common cause of thyroid disease. However, only a few studies evaluating SAT have been published in recent years with varying diagnostic criteria. We evaluate the clinical presentation and long-term outcome of isotope scan-confirmed SAT. Methods: A retrospective study of 38 patients with isotope scan-confirmed SAT was performed at a single isotope department. All patients were contacted for long-term follow-up. Results: The female/male ratio was 1.4:1, and mean age was 47 ± 14 years and 62 ± 12 years in women and men, respectively (p = 0.002). Almost half of the cases (42%) occurred during the summer. The most common symptoms were neck pain (74%) and weakness (61%). Palpitations, weight loss, heat intolerance, and sweating appeared in 50%, 42%, 21%, and 21%, respectively. Only half of the patients reported fever. TSH level was low in all patients, and mean FT4 and FT3 level were about twice the upper limit of normal range. Elevated CRP and ESR occurred in the majority (88%) of patients. The mean time period between the first clinic visit and performing thyroid function tests was 8 ± 7 days. One-third of the patients initially received a diagnosis of upper respiratory tract infection (URI). NSAIDs and steroids were prescribed to 47% and 8% of patients, respectively. Long-term follow-up of 33.5 months (range 9–52) revealed that 25% remained with subclinical or overt hypothyroidism. Conclusions: These data demonstrate that although SAT is a common entity, there is still a significant delay in diagnosis, and in a third of our patients, the initial diagnosis was URI, with 25% developing long-term hypothyroidism.

Role of Total Thyroidectomy in Painful (Symptomatic) Hashimoto's Thyroiditis: Descriptive Study

Hakura Hashimoto described Hashimoto's Thyroiditis (HT) in 1912. In HT, there occurs formation of antibodies against the self (thyroid), which causes enlargement of the thyroid gland as a whole and decreased thyroid hormone levels. Most of the patients with HT are given medical line of management (hypo/hyperthyroidism). The indications for surgical line of management for HT are due to pressure symptoms over the trachea and oesophagus, pain in the thyroid gland and for chance of malignancy. Surgical treatment gives complete relief from pain and pressure symptoms and also prevents the risk of malignancy. To evaluate the outcome and complications of total thyroidectomy in painful (symptomatic) Hashimoto's thyroiditis. It was a Hospital based Descriptive study conducted in tertiary care teaching hospital by ENT Department, Sri Manakula Vinayagar Medical College and Hospital, Pondicherry from Nov 2017 to May 2019. Sample size was 30. All patients with symptomatic (painful) HT was given trail of medical therapy (steroids and NSAIDS), following repeated attempts of failed medical therapy, surgical management (total thyroidectomy) was preferred. Visual Analog Scale (VAS) was used to assess the pain grading pre and post operatively. MS Excel and SPSS trial version 20 software was used to analyze the data. The Wilcoxan Signed Ranked test was used as test of significance to identify the difference between ordinal variables. In this study, all the 30 patients had pain as the predominant symptom. Visual Analog Scale was used to grade the pain in all the patients preoperatively and 2 weeks postoperatively. All the patients had significant reduction in the pain following total thyroidectomy, when compared to pre-operative VAS grading. Total thyroidectomy is the technique of choice in surgical treatment of symptomatic Hashimoto's thyroiditis (pain, tenderness and pressure symptoms) which warrants a radical and definitive control of the disease, without any risk of relapse and without the side effects of medical management. Moreover in longstanding cases of HT, the risk of malignant transformation is prevented due to total thyroidectomy. In experienced hands it assures total relief of compressive and painful symptoms and low incidence of/nil major complications.

Painful Subacute Thyroiditis is Commonly Misdiagnosed as Suspicious Thyroid Nodular Disease

Objective

To investigate and characterize the clinical and radiologic features of 10 patients with painful subacute thyroiditis with ultrasound findings considered suspicious for malignancy or for whom biopsy of a suspicious area was recommended by an attending radiologist.

Patients and Methods

Ten patients with painful subacute thyroiditis were seen from June 1, 2016, through January 1, 2019. All 10 patients presented to an endocrine or thyroid clinic with a neck ultrasound report stating findings suspicious for malignancy or nodular disease. Clinical, laboratory, radiographic, and pathologic data were (retrospectively collected and) reviewed.

Results

The mean ± SD patient age was 49.0±15.0 years at diagnosis; 8 patients were female. All the patients presented with a low or undetectable serum thyrotropin level. Six of 7 patients with available inflammatory markers had elevated levels. Thyrotropin receptor antibodies were absent in all 6 patients tested. On follow-up imaging, 8 patients had complete resolution or improvement of described findings, 1 was lost to follow-up, and 1 had an incidental nodule that was biopsied after the episode of thyroiditis and found to be papillary thyroid carcinoma.

Conclusion

Painful subacute thyroiditis demonstrates specific sonographic patterns that may be misdiagnosed as suspicious thyroid nodular disease. Recognition of the innocent and transient nature of these findings is important for the proper management and monitoring of these patients.

Risk Factors for Subacute Thyroiditis Recurrence: A Systematic Review and Meta-Analysis of Cohort Studies

BACKGROUND

Subacute thyroiditis (SAT) is a self-limited inflammatory thyroid disease with recurring episodes. However, the results regarding the recurrence rate and risk factors for SAT are inconsistent. This meta-analysis aimed to summarize the evidence of the recurrence rate and the risk factors for SAT.

METHODS

The present study involved the performance of a systematic literature search of all English studies published in PubMed, Embase, Web of Science, and The Cochrane Library from inception to August 20, 2021. Cohort studies that reported the SAT recurrence rate and risk factors for recurrence were included. Two independent investigators extracted relevant information. Fixed- and random-effects models were used to pool effect sizes based on study heterogeneity.

RESULTS

Eighteen cohort studies were identified. The pooled findings showed that the recurrence rate was 12.0% (95% CI: 8.2%, 17.1%). The risk of recurrence in the glucocorticoids group was higher than that in the NSAIDs group (RR = 1.84, 95% CI: 1.04, 3.24). However, there was no significant difference in age or sex between the recurrence group and the non-recurrence group. Findings from one or two cohort studies also indicated that the copresence of HLA-B*18:01 and -B*35, the number of days required to taper prednisolone (PSL) to 5 mg/day, the duration of disease before treatment less than 30 days, the sialic acid level, or the TSH level at the termination of treatment and further extension of the hypoechoic area and increase in thyroid volume were related to the recurrence of SAT.

CONCLUSION

Recurrence was common in SAT patients. The present study indicated that glucocorticoid treatment was associated with a higher recurrence rate of SAT than NSAIDs treatment. The clinical implications of this association should be interpreted with caution, and further clinical trials on the long-term effects of different treatment strategies are needed.

Subacute thyroiditis with airway compromise in a 5-year-old boy

A 5-year-old boy presented with intermittent fever for 1 month, painful neck swelling associated with dysphagia, hoarseness of voice for 3 weeks and dyspnoea of 1-day duration. On evaluation, he had elevated serum thyroglobulin levels and inflammatory markers. There was a diffuse glandular thyroid enlargement with hypoechoic areas on neck ultrasonography. Fine-needle aspiration cytology was suggestive of subacute thyroiditis (SAT), and MRI of the neck confirmed narrowing of the trachea by the enlarged thyroid. He received steroids to relieve airway compression. Levothyroxine was started. On follow-up, he was symptom-free and euthyroid; steroids and levothyroxine were discontinued. SAT presenting with compression of trachea is rare in children. This highlights the need for identifying the type of thyroiditis to determine treatment modality.

Two-Years Prospective Follow-Up Study of Subacute Thyroiditis

Purpose: The aim of the present prospective follow-up study was to explore the early indicators of hypothyroidism and the final changes in thyroid volume in subacute thyroiditis (SAT) patients. Methods: We enrolled 61 SAT patients and followed them up for 2 years to assess the incidence of hypothyroidism and changes in thyroid volume. Binary logistic regression and receiver operating characteristic (ROC) curves were used for data analysis. Results: During the 2 years follow-up period, we found that the volumes of the thyroid gland in SAT patients at 1 and 2 years were significantly smaller than those in the healthy control group, which were significantly smaller compared to the initial thyroid volumes after SAT onset (p < 0.001). Also, the thyroid volumes of SAT patients with hypothyroidism were significantly smaller than those of SAT patients without hypothyroidism. The early maximum thyroid-stimulating hormone (TSH) values (within 3 months after SAT onset) were closely related to the incidence of hypothyroidism at 2 years. The OR value was 1.18 (95% CI = 1.01-1.38, p = 0.032). The early maximum TSH value had a maximum area under the ROC curve (AUC) of 0.866 for the development of hypothyroidism 2 years after SAT onset vs. euthyroidism (p < 0.001). Conclusions: The thyroid volumes of patients increased significantly after the onset of SAT, while during the follow-up these volumes decreased; the thyroid volumes at 1 and 2 years were significantly smaller than those of normal healthy subjects, especially in SAT patients with hypothyroidism. Furthermore, the early maximum TSH value could be used as an effective indicator of the development of hypothyroidism 2 years after the onset of SAT.

Clostridium difficilecolitis in the setting of subacute thyroiditis: the chicken or the egg

Subacutethyroiditis is a self-limited inflammatory condition commonly of viral aetiology, that manifests through phases of thyroid hormone changes over a 6–8 month period. A 24-year-old active duty military man, undergoing treatment for recurrentClostridiumdifficileinfection, presented for clinical evaluation and was found to have a thyroid stimulating hormone level of 0.003 mg/dL. Further labs revealed a normal T4, elevated T3 at 5.0 pg/mL and elevated C reactive protein at 3.69 mg/L. The patient was followed with monthly labs and the abnormal thyroid stimulating hormone and triiodothyronine levels resolved after the completion of hisC. difficiletreatment. While subacute thyroiditis has historically been due to viral causes, rarely do we see this condition associated with an intestinal bacterial source.

Treatment of Acute Painful Thyroiditis with Low Dose Prednisolone: A Study on Patients from Western Nepal

INTRODUCTION

Thyroiditis is a disorder that involves inflammation of the thyroid gland. Subacute thyroiditis is the most common cause of acute painful thyroiditis. It is thought to be a viral inflammatory disorder. Subacute thyroiditis has been treated with either nonsteroidal anti-inflammatory drugs (NSAIDs) or high dose corticosteroids. The response to steroids is more dramatic and quicker than the NSAIDs. Prednisolone is the most commonly used corticosteroid to treat subacute thyroiditis. The usual dose is one mg/kg/day tapered over six weeks although the basis for this dose has not been established yet by prospective studies.

AIM

The current research was carried out to study if prednisolone in lower initial dose (20 mg/day tapered over four weeks) is effective in patients with acute painful thyroiditis.

MATERIALS AND METHODS

This study was a prospective, cross sectional, observational study carried out at Pokhara, Nepal. All the patients presenting with anterior neck pain of less than 1 week with tender thyroid on palpation and ESR more than 30mm/h were included in the study. The patients were administered prednisolone in a starting dose of 20 mg/day tapered over four weeks. Data were collected, analysed and the results were interpreted.

RESULTS

One hundred and twenty two patients of acute painful thyroiditis were included in our study. Age of the patients ranged from 19 years to 69 years with the mean age of 36.58 years. Female to Male ratio was 10:1. Mean ESR was 57.03 at the time of presentation. ESR decreased to 29.63 at two weeks and 17.03 mm per hour (normal) at 4 weeks after continuation of the drug. All the patients reported with severe pain in the anterior neck at the time of presentation. Pain was completely relieved in 115 patients (94%) at 2 weeks after starting the treatment and it was better than previous in seven patients.

CONCLUSION

Twenty mg of prednisolone daily tapered over 4 weeks is an adequate treatment of subacute thyroiditis. However, dose can be drastically tapered after 2 weeks.

Benign conditions of the thyroid gland

Infectious and autoimmune diseases account for the majority of benign conditions of the thyroid gland. They are usually diagnosed and followed by clinical examination and laboratory analyses, but when imaged, ultrasonography and computed tomography are the modalities of choice. In particular, fine needle aspiration under ultrasound guidance may be invaluable for diagnostic and therapeutic purposes.

Eponym : de Quervain thyroiditis

de Quervain thyroiditis is a self-limited inflammatory disorder of the thyroid gland. It is an uncommon disease in adults and very rare in children. Fritz de Quervain, a Swiss surgeon, who was an authority on thyroid disease, described the unique pathology of this disease. Granulomatous changes with giant cells in thyroid tissue are the pathological findings. Viral infection in genetically predisposed individuals has been proposed as the pathogenesis of the disease. Clinical hallmarks for the diagnosis are painful thyroid enlargement, elevated erythrocyte sedimentation rate, and C-reactive protein as well as decreased uptake of the thyroid gland on thyroid scintigraphy. In addition, thyrotoxicosis is present in about 50% of cases in early phase of the disease. Serum thyroglobulin level is usually elevated. Only symptomatic treatment with analgesics is usually required for pain relief. Glucocorticoid therapy may be used in severely ill patients. de Quervain thyroiditis is generally completely resolved without complications in 6-12 months. However, permanent hypothyroidism and recurrent disease have been reported in some patients.

de Quervain thyroiditis in a young boy following hand-foot-mouth disease

de Quervain thyroiditis, also known as subacute thyroiditis, is a self-limited inflammatory disease of the thyroid gland. It is extremely rare in children. The hallmarks for diagnosis are painful thyroid enlargement, elevated inflammatory markers, and decreased uptake of the thyroid gland on thyroid scintigraphy. Viral infection has been proposed to be associated with de Quervain thyroiditis. Coxsackie virus has been reported to be one of the viruses associated with the disease. To our knowledge, childhood de Quervain thyroiditis associated with hand-foot-mouth disease caused by coxsackie infection has never been reported. We report a 2.7-year-old boy who presented with typical features of de Quervain thyroiditis following hand-foot-mouth disease caused by coxsackie B4 infection. He had a brief thyrotoxic phase initially, followed by transient hypothyroid phase and euthyroidism thereafter. His thyroid scintigraphy showed a typical faint uptake at the diagnosis, and an improvement of the thyroid scan and uptake was shown 8 weeks later. He was treated with prednisolone and nearly complete resolution was documented within 2 months. Careful evaluation of the patient led to the correct diagnosis and appropriate management.

Acute thyrotoxicosis secondary to destructive thyroiditis associated with cardiac catheterization contrast dye

BACKGROUND

Thyrotoxicosis caused by destructive thyroiditis is self-limited and results from the subacute release of preformed thyroid hormone. Common etiologies include painful subacute thyroiditis and silent (painless) subacute thyroiditis (including postpartum thyroiditis, amiodarone-associated destructive thyroiditis, and lithium-associated thyroiditis). Thyrotoxicosis commonly evolves slowly over a matter of weeks.

PATIENT FINDINGS

We report a unique case of severe thyrotoxicosis caused by acute- onset painful destructive thyroiditis in a patient who received large amounts of nonionic contrast dye Hexabrix® for cardiac catheterization. The results of thyroid function and physical examination were normal before the catheterization.

SUMMARY

The acute onset of severe thyroid pain, rapid increase in serum Free Thyroxine Index, and thyroglobulin concentrations with a triiodothyronine to free thyroxine index ratio of < 20 to 1 were compatible with an acute onset destructive thyroiditis, likely related to direct toxicity from the iodinated contrast material.

CONCLUSIONS

In light of the large number of patients who receive these contrast agents during cardiac catheterization, clinicians should be advised of this potentially serious complication, particularly in the setting of unstable cardiac disease.

Subacute thyroiditis presenting as a focal lesion on [18F] fluorodeoxyglucose whole-body positron-emission tomography/CT

A 52-year-old man presented with subacute thyroiditis and showed an intensely hypermetabolic thyroid lesion on (18)F-FDG PET/CT. The patient also had coexisting chronic lymphocytic thyroiditis. The lesion of subacute thyroiditis revealed an SUV(max) of 9.1 g/mL and was ill-defined, heterogeneous, markedly hypoechoic, and hypovascular on US. Biopsy demonstrated histologic findings of subacute thyroiditis, which should be included in the differential diagnosis of an intensely hypermetabolic thyroid lesion on (18)F-FDG PET/CT.

Subacute thyroiditis following influenza vaccine (Vaxigrip) in a young female

Subacute thyroiditis (SAT), also called de Quervain thyroiditis or granulomatous thyroiditis, is a self-limiting, possibly viral, and inflammatory thyroid disorder that is usually associated with thyroid pain and systemic symptoms. This report details a case of SAT possibly associated with influenza vaccine (Vaxigrip) in a young female. The diagnosis, therapeutic management and outcome are discussed.

Thyrotoxicosis and low iodine uptake in a woman with graves' disease

Thyrotoxicosis factitia is defined as thyrotoxicosis resulting from exogenous ingestion of thyroid hormone, usually in patients with a psychiatric disorder. Diagnosis can be difficult and this entity should be suspected in patients with high free tiroxine (T4) concentrations, low or suppressed thyroglobulin concentrations, normal urinary iodide excretion and low or suppressed (131)I uptake. To establish the differential diagnosis, thyrotoxicosis factitia must be distinguished from several diseases with low (131)I uptake, such as Graves' disease, subacute thyroiditis, hyperthyroidism due to excessive iodine intake, struma ovarii and metastasis from thyroid cancer. Treatment is based on b-blockers to reduce symptoms and avoid iatrogeny. We present a case of thyrotoxicosis factitia treated in our outpatient clinic.

Primary tuberculosis of thyroid gland: a rare case report

Tuberculosis of the thyroid gland is a rare entity, and primary tuberculosis of thyroid is even uncommon. At one time, it was believed that thyroid gland is relatively immune to tuberculosis. There are about 200 cases of thyroid tuberculosis that had been reported in world literature. These include 156 cases reviewed by Goldfarb et al (Am J Med 1965;38:825) and 1 each by Crompton et al (Tubercle 1969;50:61-64), Johnson et al (Br J Surg 1973;60:668-669), Emry (J Laryngol Otol 1980;94:553-558), and Kukreja and Sharma ML (Ind J Surg 1982;44:190-192), and a histologic diagnosis by Das et al (Acta Cytol 1992;36:517-522) and Mondal and Patra (J Laryngol Otol 1995;109:36-38). Almost all cases had primary foci elsewhere in the body. Isolated tuberculosis of the thyroid gland is extremely rare, with few reported cases; when it does occur, it may prove difficult to diagnose (J Laryngol Otol 1980;94:553-558). Among the different manifestations of tuberculous thyroiditis, abscess of the thyroid appears to be the rarest and the most dangerous (Tubercle 1969;50:61-64). Sachs et al (Am J Med 1988;85:573-575) reported 4 cases of tuberculous thyroiditis that were diagnosed preoperatively, the rest of the cases were diagnosed either from surgical specimen or from autopsy. A case of primary tuberculosis of thyroid gland presenting as abscess and diagnosed preoperatively is reported here.

Incessant ventricular tachycardia due to subacute thyroiditis

Subacute thyroiditis is a possibly viral, inflammatory thyroid disorder which can cause thyrotoxicosis. Ventricular arrhythmias are uncommon in thyrotoxicosis and usually occur only in those with marked heart failure or associated cardiac disease. In this case, we present a 52-year-old woman having incessant ventricular tachycardia due to subacute thyroiditis without underlying cardiac disease.

Subacute thyroiditis: Fine-needle aspiration cytology of 14 cases presenting with thyroid nodules

Subacute thyroiditis (SAT) is usually diagnosed clinically without the need for fine-needle aspiration. The cytologic literature on this condition is therefore rare. We report on 14 cases of SAT presenting with thyroid nodules. The majority of patients were women with a mean age of 46 yr. All had pain/tenderness in the thyroid area accompanied by fever or an elevated ESR. The salient cytologic features included cellular smears; multinucleated giant cells in 100% of cases, some ingesting colloid or neutrophils; fibrous fragments with enmeshed inflammatory cells were a constant feature; follicular cells were scant to absent in most cases. Granulomas were rare. Colloid, when present was thick, with central cracks and frayed edges. One case was suspicious for malignancy. We conclude that the cytologic features of SAT are predictable, particularly, in the appropriate clinical setting. FNA is also helpful in ruling out concomitant neoplastic conditions.

Inflammatory thyroid disorders

Inflammatory thyroid disorders encompass a broad spectrum of diseases that are generally self-limited, and relatively easy to diagnose and manage. Autoimmune subtypes are by far the most commonly encountered diagnoses and create the most confusion because of simultaneous overlap and the potential for interconversion among the subtypes. The otolaryngologist will frequently see these disorders and provide valued consultative care and surgical intervention as needed.

Atypical subacute thyroiditis: preliminary observations

Nine patients with painless or minimally painful subacute thyroiditis were seen between late June and October 2000. Six had a history of antecedant viral symptoms. Thyroid peroxidase antibodies were negative in eight patients tested; none had a family history of autoimmune thyroid disease. It is possible that these patients represent examples of postviral painless subacute thyroiditis (atypical subacute thyroiditis). In order to establish the nature of the syndrome, cytological examination, HLA typing, and long-term follow-up are necessary.

De Quervain's subacute thyroiditis presenting as a painless solitary thyroid nodule

We describe a 39-year-old woman presenting with a painless solitary thyroid nodule, initially without signs suggesting thyroiditis. The serum level of thyrotropin was suppressed whereas those of thyroxine and triiodothyronine were normal. Fine needle aspiration cytology showed no signs of inflammation or malignancy. One week later, the patient felt pain and tenderness on her neck, and erythrocyte sedimentation rate and C-reactive protein were markedly elevated. Thyroid scintigraphy showed a suppressed thyroid pertechnetate uptake. At that time, the diagnosis of subacute thyroiditis was made. Upon treatment with steroids the patient's symptoms as well as the thyroid nodule resolved. This case illustrates that subacute thyroiditis de Quervain may present as a solitary, painless nodule with suppressed thyrotropin and should therefore be considered in the differential diagnosis of such lesions.

TSH receptor antibody-associated thyroid dysfunction following subacute thyroiditis

OBJECTIVE

Autoimmunity plays an important role in the development of thyrotrophin (TSH) receptor antibodies and the pathogenesis of Graves' disease and Hashimoto's thyroiditis. On the other hand, subacute thyroiditis is a self-limited inflammatory disease of presumed viral aetiology. The aim of this study was to examine whether subacute thyroiditis triggers TSH receptor antibody-associated thyroid disorders.

PATIENTS

We reviewed 1,697 patients with subacute thyroiditis seen between 1985 and 1995.

DESIGN AND MEASUREMENTS

We measured antibodies which inhibit the TSH binding to the TSH receptor (TBIAb), thyroid stimulating antibodies (TSAb) and antibodies that block TSH action (TBAb). Other thyroid autoantibodies were also determined.

RESULTS

TBIAb became positive in 38 patients following subacute thyroiditis. Thyroid function after the development of TBIAb appeared to be influenced by the bioactivity of the antibody. Hyperthyroidism developed in the presence of TSAb, and so did hypothyroidism in the presence of TBAb, although 21 patients did not have thyroid dysfunction despite high titres of TBIAb. Fifteen out of 17 patients recovered from hyperthyroidism or hypothyroidism after the disappearance of TBIAb sometimes even without medication. TBIAb-positive patients had a high incidence of a family history of thyroid disease and positive anti-thyroid microsomal antibodies. An ophthalmopathy similar to Graves' disease was also observed in 3 patients.

CONCLUSIONS

Subacute thyroiditis may trigger autoreactive B cells to produce TSH receptor antibodies, resulting in TSH receptor antibody-associated thyroid dysfunction in some patients.

Syndromes of thyrotoxicosis with low radioactive iodine uptake

It is very important to diagnose correctly the etiology of thyrotoxicosis, because the course and treatment of thyrotoxicosis with low radioactive iodine uptake differ significantly from that of hyperthyroidism due to Graves' disease or toxic nodular goiter. Many causes of subacute thyroiditis have been identified producing a characteristic course of transient hyperthyroidism, followed by hypothyroidism, and usually recovery. Ectopic hyperthyroidism includes factitious thyroid hormone ingestion, struma ovarii, and, rarely, large deposits of functioning thyroid cancer metastases. Iodine-induced hyperthyroidism may be associated with low radioiodine uptakes. Amiodarone-associated hyperthyroidism may be the result of subacute thyroiditis or iodine-induced hyperthyroidism; assessment and treatment can be quite challenging.

Fine-needle aspiration of subacute granulomatous thyroiditis (De Quervain's thyroiditis): a clinico-cytologic review of 36 cases

Although subacute granulomatous thyroiditis (SGT) is usually diagnose clinically, there are other thyroid conditions that must be ruled out. This task is achieved by means of fine-needle aspiration (FNA). In retrospect, the clinical and cytologic findings seen in 36 SGT cases are reassessed with a view to deciding which findings are most reliable for reaching a confident cytologic diagnosis. These are: the simultaneous presence in the same aspirate of the following cells: 1) follicular cells with intravacuolar granules and/or plump transformed follicular cells; 2) epithelioid granulomas; 3) multinucleated giant cells; 4) an acute and chronic inflammatory dirty background; 5) the absence of the following cells: fire-flare cells, hypertrophic follicular cells, oncocytic cells, and transformed lymphocytes. The absence of one or more of these requirements does not exclude SGT but does increase the number of thyroid conditions that come into the differential diagnosis. In these cases, it is essential to review clinical data carefully and to submit the patient to a close clinical and FNA follow-up.

The value of ultrasonography in the diagnosis and follow-up of subacute thyroiditis

Twenty-three consecutive patients with clinical and biochemical suspicion of subacute thyroiditis (SAT) were evaluated by ultrasonic scanning of the thyroid. Ultrasonic findings supported the diagnosis in all cases. In the 16 patients in whom thyroid scintigraphy was performed this was compatible with SAT. Initially, median thyroid volume was 40 mL (range 20-289) and a very low echogenicity was demonstrated in all patients. The extension of hypoechogenicity exceeded 75% in the majority of patients. Thyroid volume was significantly reduced to a median of 13 mL (range 9-40) (68% reduction, p < 0.00001) at a median follow-up period of 18 months (range 6-33) and a majority of the patients (60%) had persistent morphological abnormalities. No correlation between thyroid function and the extension of hypoechogenicity initially or at end of follow-up could be demonstrated. Recurrence was noted in 8 patients (35%), two of whom were positive for anti-TPO antibodies, but the risk of recurrence could not be correlated to the extension of hypoechogenicity or initial thyroid function. Recurrence was related to the further extention of hypoechoic areas and increase in thyroid volume, as evidenced by ultrasonography in our series. None developed thyroid antibodies, and all were euthyroid at the end of the observation period. We believe that high resolution ultrasonography has a useful supporting role in the diagnosis of subacute thyroiditis. In case of doubt and differential diagnostic considerations, it facilitates guided biopsies. Additionally, it allows determination of disease activity and thyroid size.

Efficacy of fine needle aspiration cytology in the diagnosis of tuberculosis of the thyroid gland: a study of 18 cases

Tuberculosis of the thyroid gland is an extremely rare condition. Amongst 1565 cases of thyroid lesions subjected to fine needle aspiration cytology (FNAC) over a period of nine years, 18 cases (1.15 per cent) were found to have cytological features consistent with tuberculosis thyroiditis. Acid-fast bacilli were isolated in all cases. The ages of the patients ranged from 36 to 52 years with a median age of 46 years: there were 12 females and 6 males. All the patients presented with painless solitary nodules of the thyroid. Three patients had concomitant cervical lympadenopathy and four patients were known to have tuberculosis of the lungs which was being treated. Solitary nodules of the thyroid were confirmed by a thyroid scan with radioactive iodine. Fine needle aspirates from thyroid swellings showed epithelioid granulomas with necrosis in all cases. There were no false reports or complications. It is evident from this study that FNAC is an efficient way with which to detect tuberculosis of the thyroid gland.

Fine needle aspiration cytodiagnosis of subacute (de Quervain's) thyroiditis in an endemic goitre area

Between 1977 and 1989 252 fine needle aspirates (FNAs) of the thyroid from patients with a clinical suspicion of subacute granulomatous (de Quervain's) thyroiditis were examined in the Department of Pathology of the University of Innsbruck, Austria. In the same period 31 cases with preoperative FNA were diagnosed histologically as subacute thyroiditis. Only in three of these cases were the cytological features of de Quervain's thyroiditis found in the preoperative FNA. However, in 13 of these 31 cases a cytological suspicion of malignancy was obtained. Subsequent histological examination revealed an acute phase inflammation of de Quervain's thyroiditis in most of these cases. We conclude that an accurate FNA diagnosis of de Quervain's thyroiditis, particularly in the acute stage, may cause difficulties due to a lack of typical features and the appearance of atypical thyroid follicular cells. For the cytopathologist, accurate clinical information relating to the possibility of de Quervain's thyroiditis is essential if unnecessary surgery is to be avoided.

The management of subacute (DeQuervain's) thyroiditis

Subacute (DeQuervain's) thyroiditis is a transient inflammatory thyroid disease usually associated with pain and tenderness of the gland, as well as generalized somatic symptoms, which can cause great discomfort or even complete prostration for weeks or months if left untreated. It is almost certainly the result of a viral infection. There is no definitive therapy for painful subacute thyroiditis, but there is effective treatment that will ameliorate the symptoms and allow the disease to run its spontaneous course in an asymptomatic fashion. Salicylates and nonsteroidal antiinflammatory drugs can be used in patients with mild or moderate forms of the disorder. In more severe forms of the condition, corticosteroids in suitable pharmacological dosage will generally cause a rapid relief of symptoms within 24-48 h. Prednisone may be initiated in dosages of 40 mg daily, with a gradual reduction in dosage thereafter over several weeks. Recurrences do appear in a small percentage of patients, necessitating restoration of a higher dose once again. Repeat exacerbations are uncommon. Other less common forms of treatment include triiodothyronine or thyroxine, generally to prevent repeated exacerbations. Irradiation is no longer employed. Thyroidectomy should be considered only in that very small minority of patients who have repeated relapses despite appropriate treatment. During the period of transient hypothyroidism, thyroxine may be provided but can usually be discontinued subsequently. General recovery is almost the universal rule and only less than 1% become permanently hypothyroid.

Thyroid abscess complicating subacute thyroiditis: a consequence of steroid therapy?

A patient with subacute thyroiditis developed a thyroid abscess after drainage of a pilonidal abscess. An infective focus in a patient with subacute thyroiditis on steroids should be treated aggressively with adequate antibiotic cover.

Transient thyrotoxicosis and persistent hypothyroidism due to acute autoimmune thyroiditis after interleukin-2 and interferon-alpha therapy for metastatic carcinoma: a case report

A 59-year-old man with metastatic renal cell carcinoma developed symptomatic thyroid dysfunction following interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) therapy. Thyroid evaluation prior to this therapy revealed evidence of subclinical Hashimoto's thyroiditis. Symptomatic thyrotoxicosis, including atrial fibrillation, developed after the initial two courses of intermittent intravenous bolus therapy with human recombinant IL-2 and IFN-alpha. At 4 weeks after initiation of immunotherapy, the thyroid antimicrosomal antibody (AMA) titer rose from 1:6,400 to 1:25,600; thyroid-stimulating immunoglobulin was negative. A technetium 99m-pertechnetate thyroid scan obtained while the patient was thyrotoxic showed diminished uptake in a symmetrically enlarged gland. The patient was temporarily treated with propranolol, digoxin, and quinidine. The atrial fibrillation quickly resolved, and thyrotoxicosis abated over the following 5 weeks, while the AMA titer rose further to 1:102,400. By 11 weeks after initiation of immunotherapy, hypothyroidism developed and persisted through two subsequent courses of cytokine therapy at Weeks 16 and 18. The tumor metastases partially responded to the immunotherapy. The patient has remained hypothyroid up to 27 weeks of follow-up. This case history suggests that IL-2 and IFN-alpha therapy may precipitate a fulminant autoimmune thyroiditis syndrome in a vulnerable patient with preexisting autoimmune thyroid disease.

Thyroiditis. Acute, subacute, and chronic

Inflammatory diseases of the thyroid are collectively the commonest thyroid disorder. Individually, they range from the rare case of acute bacterial thyroiditis to the other end of the spectrum, the even rarer Riedel's thyroiditis. Relatively common thyroid inflammatory diseases include the subacute thyroiditis syndromes. Of particular interest to endocrinologists is that both subacute granulomatous (painful) thyroiditis and subacute lymphocytic (painless) thyroiditis are very similar in terms of clinical course, although most likely have different etiologies. Nevertheless, their similarities suggest the possibility that there may be etiologic heterogeneity for the syndromes. From a clinical standpoint, it is essential to differentiate subacute painless thyroiditis from Graves' disease, because these two disorders also may mimic each other, yet only Graves' disease requires specific therapy. Chronic lymphocytic (Hashimoto's) thyroiditis, the commonest of the thyroiditides, presents with goiter and either hyperthyroidism (uncommon), hypothyroidism (common), or euthyroidism (most common). When L-T4 therapy is used in the treatment of Hashimoto's thyroiditis, the physician must be alert to the possibility of excess thyroid hormone administration. Sensitive TSH measurements help to avoid this therapeutic pitfall.

Hyperthyroidism in children and adolescents

Hyperthyroidism in infants and children usually is caused by Graves' disease; however, several other diseases can also produce hyperthyroidism in these age groups. Because the pathophysiology and clinical course of these conditions differ, optimal treatment depends on precise diagnosis.

Effect of live attenuated, cold recombinant (CR) influenza virus vaccines on pulmonary function in healthy and asthmatic adults

The effects of intranasal inoculation with live attenuated, CR influenza virus vaccines on pulmonary function in healthy and asthmatic adults were evaluated in placebo-controlled, double-blind studies. In 46 healthy adult volunteers, there were no statistically significant alterations in pulmonary function as measured by spirometry and histamine bronchoprovocation tests in the first week following monovalent CR influenza virus vaccine [type A (H3N2, H1N1) and type B]. Among healthy adults with pre-inoculation PC20s less than 10 mg ml-1, 8/12 were infected following vaccination but no significant alterations occurred in histamine bronchoprovocation. In 11 asthmatic adults, no statistically significant alterations in pulmonary function, as measured by spirometry, were noted during the first 7 days postinoculation with bivalent CR influenza virus vaccine type A (H3N2 and H1N1). Postinoculation respiratory illnesses were more common in CR influenza virus vaccine recipients than placebo recipients, but they were mild, consisting of afebrile pharyngitis and transient rhinorrhea. Attenuated CR influenza virus vaccines do not appear to impair pulmonary function during the first week following immunization of healthy and asthmatic adults.

Thyroiditis. Differentiation of acute suppurative and subacute. Case report and review of the literature

Acute suppurative thyroiditis is rarely seen during childhood. The classic clinical features of this illness (fever, neck pain, and a swollen, tender mass over the thyroid gland) can differentiate acute thyroiditis from the more common subacute thyroiditis. In less typical cases, however, this distinction can be difficult. An adolescent male presented with a swollen, tender thyroid gland. Atypical laboratory findings and the lack of fever and toxicity delayed the diagnosis and treatment of acute suppurative thyroiditis. A review of the pediatric literature summarizes clinical and diagnostic features valuable in the differential between acute suppurative thyroiditis and subacute thyroiditis in childhood. The important contribution of fistulae between the piriform sinus and thyroid gland to the pathogenesis and acute suppurative thyroiditis is emphasized. Such a fistula should be sought in every patient in whom this entity is diagnosed.

Atypical presentation of subacute thyroiditis

Subacute thyroiditis is extremely rare during the first decade of life. We describe a case of subacute thyroiditis in a 2 year old child whose initial clinical, sonographic, and radioisotopic features were indistinguishable from acute suppurative thyroiditis. The diagnosis was established by a raised antibody titre against adenovirus and typical increased thyroid function tests.

Autoimmune thyroid disease: immunological, pathological, and clinical aspects

Autoimmune thyroiditis, most notably Hashimoto's thyroiditis, appears to be increasing in prevalence and is now more easily detected by sensitive laboratory tests and more invasive procedures such as fine needle aspiration. During the last decade, marked progress has been made in the understanding of these diseases. There is a greater awareness of the interaction between the humoral and cell-mediated arms of the immune system in autoimmune thyroiditis. Recent studies implicate a subpopulation of suppressor T lymphocytes which have an antigen-specific defect, resulting in their suboptimal interaction with the helper T lymphocytes and subsequent autoimmune manifestations. There is some evidence that thyroid epithelial cells which inappropriately express HLA-DR may enhance presentation of thyroid antigens to the immune system, possibly significant in the initiation or enhancement of the autoimmune response. The presence of various antithyroid autoantibodies allows the use of laboratory assays to confirm the clinical diagnosis and predict the results of treatment. There appears to be predisposing genetic factors in the development of autoimmune thyroiditis, with some geographical and racial differences. Environmental factors, most notably dietary intake of iodine, have also been implicated in the pathogenesis of Hashimoto's thyroiditis. Several animal models have been developed addressing such issues. Ongoing studies in the areas of postpartum thyroiditis and childhood thyroiditis are helpful in clarifying their relationship with Hashimoto's thyroiditis. Graves' disease and postpartum thyroiditis are being investigated as possible causes of postpartum depression. The association of Hashimoto's thyroiditis and carcinoma of the thyroid gland is still controversial, but its relationship with malignant lymphoma is now well accepted. Thus, although the pathogenesis of autoimmune thyroiditis remains elusive, there has been significant refinement of the clinical diagnosis, and immunological abnormalities of specific intrathyroidal lymphocytes have been identified. Hopefully, these new areas of knowledge will assist in the treatment of these diseases and in the prevention of the development of malignant lymphomas of the thyroid gland.

High prevalence of subacute thyroiditis during summer season in Italy

Eighty consecutive patients with typical subacute thyroiditis were evaluated. Sex distribution showed a higher incidence in females (F/M 3.2/1), with a mean age of 44 yr. In the majority of patients (51/80 = 66%) the onset of the disease was between June and September (46% in July and August). The remaining cases were distributed in the other months without a clear monthly prevalence. These results indicate that the seasonal distribution of subacute thyroiditis is almost superimposable to that of established infections due to some enteroviruses (Echovirus, Coxsackie A and B viruses), suggesting that summer enterovirus infections may be responsible for a large proportion of cases of subacute thyroiditis.

Thyroiditis

In this review, the major types of immune mediated thyroiditis are described and the etiology explained in the light of current theories of autoimmunity. Hashimoto's thyroiditis is a common autoimmune disease. The onset is gradual with patients presenting with symptoms of hypothyroidism, nonspecific symptoms of the autoimmune process itself, or symptoms relating to a goitre. The disease is usually relentless and, except in young patients, permanent replacement with thyroxine is eventually required. Silent thyroiditis is another autoimmune disease of more acute onset. The initial, thyrotoxic, phase lasting several weeks is due to release of thyroid hormone from damaged follicles, and radionuclidic scans show absent uptake. There often follows a hypothyroid phase with final recovery in most patients. Post partum thyroiditis is due to silent thyroiditis, or, less commonly, Hashimoto's thyroiditis, occurring three to six months after delivery. Subacute thyroiditis often follows a viral infection and is not thought to be an autoimmune disease. It presents with severe thyroid pain and tenderness with marked non-specific symptoms such as myalgia and fatigue. The initial, thyrotoxic, phase is also due to release of thyroid hormone, and radionuclidic scans show absent uptake. A hypothyroid phase often follows and recovery is complete. Hashimoto's thyroiditis appears to be due to a congenitally present, antigen specific, T suppressor lymphocyte defect. It is proposed that in silent thyroiditis there is a less severe Ts defect and a correspondingly greater decompensating factor. In post partum thyroiditis, this factor appears to be a general decline in T suppressor lymphocyte function after delivery. Subacute thyroiditis is not an autoimmune disease. The thyroid appears to be an "innocent bystander" in an immune mediated antiviral attack.

Subacute thyroiditis associated with Chlamydia psittaci infection

A patient presenting with subacute thyroiditis who had evidence of chlamydial infection is reported.

Humoral autoimmune manifestation in subacute thyroiditis

To study the autoimmune manifestations in subacute thyroiditis (SAT), the patterns of thyroid antibodies, thyroglobulin and circulating immune complexes were investigated in 10 patients during the course of the disease. Eight patients were thyrotoxic at diagnosis, and became euthyroid during recovery with a median observation of 8 months (4-30 months). Thyroid stimulating immunoglobulins were measured as TSH binding inhibiting immunoglobulins (TBII) and as thyroid stimulating antibodies (TSAb). TBII were present in all patients at least once during the observation period and remained detectable in six patients after recovery. TSAb were detected in three patients without relation to the hyperthyroid state. Thyroglobulin antibodies (TgAb) were present in four patients and persisted in three, while microsomal antibodies (MAb) were negative. Thyroglobulin (Tg) in the TgAb negative patients (n = 6) was high at diagnosis (median 229 micrograms/l, range 55-375) and fell rapidly during the course of SAT. Circulating immune complexes (CIC), which were found in all patients, reached maximal levels shortly after the onset of the disease and persisted after recovery. No correlation could be demonstrated between the different thyroid antibodies, and there was no clear relation between the levels of CIC and presence of the autoantibodies. However, the changes in CIC paralleled the changes in TBII, and it is suggested that immune complex formation is a major feature of the regulatory mechanisms controlling the immune responses in SAT.