What might cause pain in the thyroid gland? Report of a patient with subacute thyroiditis of atypical presentation

Subacute granulomatous thyroiditis (SAT), also known as de Quervain's thyroiditis or painful subacute thyroiditis, is the commonest thyroid condition responsible for neck tenderness. Other causes of pain in the thyroid gland should be taken into consideration during differential diagnosis, especially when a patient presents with misleading or equivocal signs and symptoms. We report the case of a 39 year-old woman diagnosed as having SAT whose clinical, biochemical and radiological presentation varied significantly from the common SAT manifestation. A tentative diagnosis of SAT was made based on the presented symptoms, ultrasonography and fine-needle biopsy results. However, biochemical analysis suggested neither inflammatory process nor the presence of thyrotoxicosis. Moreover, technetium scan of the thyroid revealed normal uptake of the isotope and there was neither clinical nor ultasonographic response for corticosteroids. The patient's symptoms, despite being prescribed typical treatment, gradually deteriorated and the pain became increasingly debilitating. Eventually, the patient underwent total thyroidectomy. As a result, she has become free of symptoms, but the macroscopic picture of thyroid gland, noted during the operation, gave a suspicion of neoplastic process. Nevertheless, histological study of flow samples confirmed the tentative diagnosis of de Quervain's thyroiditis, despite all previous findings that were not suggestive of it. This report confirms the likelihood that SAT can present atypically. Additionally, it indicates that surgical treatment may be considered in patients with severe, debilitating, persistent thyroid gland pain connected with SAT clinical course.     

Aspiration cytology of Hashimoto's thyroiditis in an endemic area

Fine needle aspiration (FNA) plays a significant role in the diagnosis of thyroid lesions due to its simplicity and low cost. Hashimoto's thyroiditis (HT) is the second most common thyroid lesion next to endemic goitre diagnosed on FNA in iodine (I2) deficient areas. Data on its incidence, prevalence and clinicopathological features in I2 deficient areas is scanty compared to I2 sufficient areas. In the present study the patients presented with HT a decade earlier than reported in I2 sufficient areas. Presentation as a nodular thyroid is common. Diagnosis of HT is likely to be missed in smears showing cytological evidence of hyperplasia or abundant colloid. HT was concurrent in 20 cases of endemic goitre. Careful screening for Hurthle cell change and lymphocytic infiltration into follicular cells should be carried out. In equivocal cases multiple punctures and immunological investigations are helpful. In antibody-negative cases repeat FNA at follow-up is useful. Marked lymphocytic infiltration and Hurthle cell change may indicate a hypothyroid state but hormonal levels are required for clinical management.     

Aspiration cytology of renal-cell carcinoma metastatic to the thyroid

Fine needle aspiration (FNA) of a thyroid mass clinically suspected of being acute thyroiditis led to a cytologic diagnosis of hypernephroma metastatic to the thyroid and to the subsequent detection of the occult primary tumor. The FNA cytomorphologic findings were substantiated by cytochemical staining of FNA samples and confirmed by subsequent histopathologic examination of the resected thyroid. Postoperative studies revealed an expansive growth in the left kidney; analysis of the nephrectomy specimen showed an invasive renal-cell carcinoma. This case emphasizes the considerable value of FNA biopsy in making the frequently difficult preoperative differential diagnosis of primary and metastatic thyroid tumor and the importance of cytochemical analyses in making that distinction and in suggesting the site of the primary tumor.     

Subacute thyroiditis associated with systemic multi-organ disorders

Subacute thyroiditis is generally thought to be a self-limited inflammatory disease of the thyroid gland. This paper describes serial observations on the clinical course of a typical patient with subacute thyroiditis. This patient showed specific features of destructive thyrotoxicosis with increases in the serum levels of acute phase reactants and in the erythrocyte sedimentation rate. She also showed signs of liver dysfunction [slightly increased alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (gamma-GTP), and leucine aminopeptidase (LAP)], slight anemia, glucose intolerance, increased pancreatic enzymes, splenomegaly, and an increase in peripheral Leu 7 positive (NK/K) cells. These abnormalities all improved with recovery from disease. These findings indicate that in this patient with subacute thyroiditis inflammation is not limited to the thyroid gland but also involves the liver, pancreas and spleen. Thus the subacute thyroiditis in this patient may be a systemic multi-organ disease.     

Fine needle aspiration cytology of thyroid gland diseases

From 1982 to 1987, 2,433 lesions of the thyroid gland in 1,796 patients were examined by fine needle aspiration (FNA). Cytopathology classified 66.91% of the aspirates as benign, 10.76% as thyroiditis, 4.89% as suspected (unspecified) neoplasia, 1.31% as positive for malignancy and 16.11% (392) as unsatisfactory. The histologic diagnoses in 257 cases were compared with cytologic diagnoses to determine the accuracy of FNA cytology of thyroid lesions, yielding a sensitivity of 71.43%, a specificity of 100% and an accuracy of 95.09%. This data strongly supports thyroid FNA as an important preoperative diagnostic tool. Follicular carcinomas were difficult to cytologically differentiate from nonmalignant follicular neoplasms, and papillary thyroid carcinomas less than 2 cm in diameter in elderly patients were frequently misdiagnosed or diagnosed only as "suspect lesion."     

小剂量糖皮质激素联合消炎痛治疗亚急性甲状腺炎的临床效果

目的:探讨小剂量糖皮质激素联合消炎痛治疗亚急性甲状腺炎(Subacute thyroiditis,ST)的临床效果及安全性。方法:选取我院内分泌科2012年6月-2014年7月收治的150例亚急性甲状腺炎患者,按照随机平均原则即药物治疗的不同将其分为三组,每组50例,即泼尼松与消炎痛联合治疗(A组)、泼尼松单独治疗(B组)、消炎痛单独治疗(C组),对比并分析三组的治疗效果,包括甲状腺疼痛和肿大平均消失时间,治疗1周的ESR平均水平,治疗4周后的血清TSH、FT3、FT4水平,并通过随访,观察治疗后8周患者不良反应的发生率、复发率。结果:(1)A组患者甲状腺疼痛和甲状腺肿大的消失时间与B组比较无显著差异(P0.05),A、B组均显著短于C组(P0.05)。A组患者治疗后1周、4周的ESR水平与B组对比差异不明显,无统计学意义(P0.05);A、B组患者治疗后1周的ESR水平明显低于C组(P0.05)。A、B组治疗后的血清TSH、FT3、FT4水平改善程度均优于C组,差异有统计学意义(P0.05)。(2)A组、C组的不良反应发生率、复发率均低于B组,差异具有统计学意义(P0.05)。结论:采用小剂量糖皮质激素联合消炎痛治疗亚急性甲状腺炎的临床效果显著,且不良反应和复发情况少。     

Cytomorphologic aspects of thyroiditis. A study of 51 cases with functional, immunologic and ultrasonographic data

Fine needle aspiration provided material for detailed cytomorphologic study in 51 cases of thyroiditis, 40 of which were diagnosed as Hashimoto's (autoimmune) thyroiditis. Of these 40 cases, 22 were found to be euthyroid on clinical examination and radioimmunoassay (RIA), 10 were hyperthyroid and 8 were hypothyroid. Of the 11 cases of subacute thyroiditis, 4 were thyrotoxic and 7 were euthyroid. Radioactive iodine uptake (RAIU) showed decreased to negligible uptake in ten and normal uptake in one case of subacute thyroiditis, whereas all of the thyrotoxic cases of Hashimoto's thyroiditis showed markedly increased RAIU. Echography showed a hypoechoic or anechoic pattern in most of the cases. Antimicrosomal and/or antithyroglobulin antibodies were positive in 25 cases of Hashimoto's thyroiditis and in 1 case of subacute thyroiditis. The cytologic features that characterized subacute thyroiditis were the presence of multinucleated giant cells and a polymorphonuclear and lymphocytic population associated occasionally with epithelioid-cell granulomas. Hashimoto's thyroiditis was characterized by Hürthle-cell changes and a significant lymphoid population consisting of mature and transformed lymphocytes, often impinging on follicular cells. There was an overlap in the cytomorphologic features between some cases of Hashimoto's and subacute thyroiditis. In such cases, the final diagnosis was arrived at by an integrated approach incorporating all of the diagnostic parameters available.     

Papillary carcinoma of the thyroid gland. Analysis of 94 cases with preoperative fine needle aspiration cytologic examination

From 1979 to 1983, 94 papillary carcinomas of the thyroid gland were examined histologically in our institute after a preoperative cytologic examination. Material for cytologic examination was obtained using fine needle aspiration (FNA) biopsy. Eighty-five (90.4%) of the 94 examined cytologic smears were representative. Among these 85 cases suspicion for malignancy or malignancy itself was found in 64 cases (75.3%). The remaining 21 smears, classified as cytologically not as suspect for malignancy, were reclassified and the previous diagnosis had to be revised in one case. In the other 20 cases no clue for malignancy could be demonstrated even after reexamination. In the 85 cases with representative cytologic findings, tumor size was determined on surgical material, in order to establish how many carcinomas with a diameter less than 3 cm could not be reached by FNA biopsy. Except for one case, all carcinomas with negative preoperative cytologic findings had a diameter less than or equal to 3 cm. The question arising is the possibility of improving the accuracy of FNA biopsy in tumor detection within cold nodules of the thyroid by combined use of scintigraphy and ultrasound-guided FNA biopsy.     

Coexistent disease as a complicating factor in the fine needle aspiration diagnosis of papillary carcinoma of the thyroid

The occasional coexistence of papillary carcinoma of the thyroid with nodular goiter or hyperparathyroidism may in some cases result in a significant discrepancy between the clinical impression and the fine needle aspiration (FNA) biopsy diagnosis, leading to the suspicion that a false-positive FNA diagnosis was obtained. Two such cases are presented in which consultation between the cytopathologist and the surgeon was helpful in achieving a correct diagnosis and ensuring proper therapy. Awareness of these variations in the clinical presentation of papillary carcinoma of the thyroid will aid the cytopathologist in the resolution of such apparent discrepancies.     

Cytoplasmic colloid inclusions in thyroid lesions: a cytomorphological study based on fine needle aspiration

INTRODUCTION: Intracytoplasmic lumens (ICL) with or without magenta material and transgressing vessels are features of Hürthle cell neoplasms (HCN). After detection of intracytoplasmic colloid inclusions (CIs) including targetoid (magenta) body-like structures in the Hürthle cells (HC) in a case of Hashimoto's thyroiditis (HT), we reviewed cases of HT, thyroid neoplasms, hyperplastic nodules (HN) and colloid goitres to determine the frequency of these structures. Further, an attempt was made to find out the significance of CIs. METHODS: FNA smears of 120 HT, 101 colloid goitres, 11 HN, and 76 neoplastic goitres were examined. The presence of CIs and empty ICL were noted in epithelial cells in these lesions. An attempt was made to find out the difference between HT with and without CIs in respect of various cytomorphologic features. The groups were compared using the Fisher's exact test of probability. RESULTS: The CIs were present in 36 (30.0%) of HT, 26 (34.2%) of neoplastic goitres, 3 (27.3%) of HN, and 4 (4.0%) colloid goitres. As compared to colloid goitres, CIs were present in a significant higher number of cases in HN (P = 0.0202), neoplastic goitres (P < 0.0001), and HT (P < 0.0001). Among neoplasms the frequency of CIs in HCN (75.0%) was significantly higher than that of papillary thyroid carcinoma (PTC) (33.3%, P = 0.0466), and follicular neoplasm (14.3%, P = 0.0083). The CIs were more frequent in HC in HT and HCN but in follicular cells (FC) in other lesions. The HT cases with CIs differed significantly from those without CIs in respect of HC and their cellularity, cellularity of reactive lymphoid cells, extracellular colloid and empty ICL. CONCLUSION: Care should be taken not to diagnose HT cases with an excessive Hürthle cell component and CIs, and PTC cases with Hürthlization and CIs, as HCN in FNA smears. Based on review of the literature and our findings, it is suggested that the Hürthle cell metaplasia in HT is a survival response of FC and the presence of CIs in Hürthle cell may represent their limited ability to synthesize colloid.     

Diagnostic value of qualitative and quantitative variables in thyroid lesions

Two hundred and thirty-three thyroid lesions were studied by fine needle aspiration (FNA) cytology using standard cytologic criteria available in the literature. These included 114 cases of nodular colloid goitre (NCG), 47 cases of Hashimoto's thyroiditis (HT), 12 follicular adenomas (FAd), five cases of subacute thyroiditis and three cases of thyrotoxicosis among the benign lesions. The malignant lesions seen were 30 cases of papillary carcinoma (PCa), 16 follicular carcinomas (FCa), three cases with double lesions, e.g. papillary carcinoma with coexisting NCG, and three of papillary carcinoma with HT. Emphasis was given to eight qualitative and quantitative (morphometric) variables in these various thyroid lesions. Cell measurements were done using a Visopan Lux projection microscope. The three qualitative variables included type of nuclear membrane (regular/irregular), type of nuclear chromatin and the presence or absence of conspicuous nucleoli. The quantitative variables studied were nuclear diameter, nuclear area, cytoplasmic diameter, cytoplasmic area & N/C ratio. Statistical analysis was performed in order to know whether the standard cytologic criteria used at FNA cytology in the literature (increased cellularity, microfollicles, increased N/C ratio, absence of significant haemosiderin-laden macrophages and scanty colloid) could differentiate a follicular adenoma from a follicular carcinoma. A statistical analysis was also performed to establish the utility of the qualitative and quantitative variables. The results showed that none of the standard cytologic criteria applied could differentiate follicular adenoma from a follicular carcinoma. With regard to qualitative variables, irregularity of nuclear membrane and presence of conspicuous nucleoli were most significant in papillary carcinoma, followed by follicular carcinoma, then by follicular adenoma; these features being hardly evident in nodular colloid goitre and Hashimoto's thyroiditis. A coarse nuclear chromatin was most significant in follicular carcinomas followed by follicular adenomas. It was less obvious in the benign conditions, but more prominent in Hashimoto's thyroiditis compared with a goitre. It was also not obvious in a papillary carcinoma. Of the quantitative variables, all measurements were greatest in PCa > FCa > FAd > NCG = HT. When differentiating follicular adenoma from follicular carcinoma the qualitative variables of significance were the presence or absence of nucleoli, the chromatin pattern and regularity/irregularity of nuclear membrane; the nuclear area was the most important feature among quantitative variables.     

Necrosis of thyroid nodules after fine needle aspiration

In a series of 200 fine needle aspirations (FNA) of the thyroid, necrosis around the needle tract was histologically evident in 2 of 30 cases with surgical follow-up. In one case of a differentiated thyroid carcinoma, necrosis with involution of the nodule was the dominant finding. This suggests that FNA can induce necrosis and apparent clinical regression of thyroid neoplasms. We believe, however, that a positive cytologic diagnosis coupled with a clinical suspicion of neoplasm should lead to surgical intervention, despite clinical regression following FNA.     

Posters. P1 A 2‐year audit of thyroid fine needle aspiration cytology

Introduction Fine needle aspiration (FNA) cytology of the thyroid is a well‐established test in the clinical work‐up of patients with solitary nodules of the thyroid. Thyroid FNA does however have limitations and audit of diagnostic performance is important. Methods The histopathology archives of the Royal Victoria Hospital were searched for all thyroid resections and the histopathological diagnosis was correlated with the pre‐operative cytological diagnosis, where available. Special emphasis was placed on the accuracy of tumour diagnosis. Results A total of 173 cases were identified during the 2‐year period, of these 93 had available pre‐operative FNA. A total of 57 tumours were identified. A small number (six of 57) of significant discrepancies were identified. These included a malignant lymphoma diagnosed as Hashimoto's thyroiditis, a metastasis which the FNA had suggested was a medullary carcinoma and an insular carcinoma diagnosed as medullary carcinoma on FNA. False positives included a colloid cyst diagnosed as suspicious of malignancy and a cytological diagnosis of papillary carcinoma not confirmed on histology. Discussion At present, the majority of thyroid FNAs in our clinics are performed by surgeons and material is not routinely available for immunocytochemistry. In spite of these limitations, there were few major discrepancies. These might be reduced if pathologist aspirators were able to perform FNAs and collect material for further studies, where necessary. This would allow identification of medullary carcinomas and malignant lymphomas. Conclusion FNA of thyroid lesions is a useful investigation in our clinical setting, however, some areas of potential for improvement have been identified.     

Atypical epithelial cells, cannot exclude papillary carcinoma, in fine needle aspiration of the thyroid

OBJECTIVE: Atypical epithelial cells, cannot exclude papillary thyroid carcinoma (AEC-PTC), in fine needle aspiration (FNA) of the thyroid is a controversial diagnostic category that might cause a dilemma in patient management. STUDY DESIGN: Eighty-eight thyroid FNA specimens from 86 patients with a diagnosis of AEC-PTC were retrieved from our files in a 10-year period from December 1996 to December 2006. Of the 86 patients, 57 had follow-up histologic diagnoses and were included in this study. The cytologic and histologic materials were reviewed and correlated. RESULTS: Of the 57 patients, all had cytologic atypical features suggestive of PTC. Twenty-five cases of PTC were identified at surgery (44%). Review of the cytologic materials identified the following cytologic features, either alone or in combination strongly associated with PTC at resection: rare intranuclear cytoplasmic invagination (INCI), squamoid cytoplasm and psammoma bodies. CONCLUSION: The most common reasons for rendering the diagnosis of AEC-PTC in FNA of thyroid include rare atypical cells in a cystic thyroid nodule or a background of Hashimoto's thyroiditis. The cytologic features of LNCI, squamoid cytoplasm and psammoma bodies should alert the pathologist. Focal cytologic features of PTC in FNA samples are strongly associated with papillary carcinoma on resection.     

Posters

Introduction  Fine needle aspiration (FNA) cytology of the thyroid is a well-established test in the clinical work-up of patients with solitary nodules of the thyroid. Thyroid FNA does however have limitations and audit of diagnostic performance is important.
Methods  The histopathology archives of the Royal Victoria Hospital were searched for all thyroid resections and the histopathological diagnosis was correlated with the pre-operative cytological diagnosis, where available. Special emphasis was placed on the accuracy of tumour diagnosis.
Results  A total of 173 cases were identified during the 2-year period, of these 93 had available pre-operative FNA. A total of 57 tumours were identified. A small number (six of 57) of significant discrepancies were identified. These included a malignant lymphoma diagnosed as Hashimoto's thyroiditis, a metastasis which the FNA had suggested was a medullary carcinoma and an insular carcinoma diagnosed as medullary carcinoma on FNA. False positives included a colloid cyst diagnosed as suspicious of malignancy and a cytological diagnosis of papillary carcinoma not confirmed on histology.
Discussion  At present, the majority of thyroid FNAs in our clinics are performed by surgeons and material is not routinely available for immunocytochemistry. In spite of these limitations, there were few major discrepancies. These might be reduced if pathologist aspirators were able to perform FNAs and collect material for further studies, where necessary. This would allow identification of medullary carcinomas and malignant lymphomas.
Conclusion  FNA of thyroid lesions is a useful investigation in our clinical setting, however, some areas of potential for improvement have been identified.     

FNA diagnosis of poorly differentiated thyroid carcinoma. A review of the recent literature

Poorly differentiated thyroid carcinoma (PDTC) is a follicular cell‐derived tumour that was recognised as a distinct entity by the World Health Organisation in 2004. The natural history and pathological features of PDTC are reported to be intermediate between those of well‐differentiated and undifferentiated (anaplastic) thyroid carcinomas. Preoperative identification of PDTC could facilitate better initial patient management in many cases, namely more extensive surgery, without any delay. However, according to some experts, a diagnosis of PDTC can only be rendered on histologic specimens based on criteria recommended in the Turin proposal. Although high‐grade features (namely necrosis and mitoses) can be recognised in FNA material, other cytomorphological features have limited value for the preoperative diagnosis of PDTC and specific features for a definitive diagnosis of PDTC have not yet been clearly defined. Here, we review the current status and future prospects for cytological recognition of PDTC; we emphasise the features that should raise suspicion of this rare condition in FNA cytology and provide an update on molecular features and management of PDTC. Despite proposed histological criteria for the diagnosis of PDTC, its recognition on routine thyroid cytology presents a notable challenge. Current and future advances in molecular testing could contribute to the cytological diagnosis of PDTC.     

Fungal Thyroiditis: An Overview

The authors review the epidemiology, clinical manifestations, diagnosis, and treatment of fungal thyroiditis cases previously reported in the medical literature. Aspergillus was by far the most common cause of fungal thyroiditis. Immunocompromised patients, such as those with leukemia, lymphoma, autoimmune diseases, and organ-transplant patients on pharmacological immunosuppression were particularly at risk. Fungal thyroiditis was diagnosed at autopsy as part of disseminated infection in a substantial number of patients without clinical manifestations and laboratory evidence of thyroid dysfunction. Local signs and symptoms of infection were indistinguishable from other infectious thyroiditis and included fever, anterior cervical pain, thyroid enlargement sometimes associated with dysphagia and dysphonia, and clinical and laboratory features of transient hyperthyroidism due to the release of thyroid hormone from follicular cell damage, followed by residual hypothyroidism. Antemortem diagnosis of fungal thyroiditis was made by direct microscopy and culture of a fine-needle aspirate, or/and biopsy in most cases. Since most patients with fungal thyroiditis had disseminated fungal infection with delay in diagnosis and treatment, the overall mortality was high.     

慢性淋巴细胞性甲状腺炎合并甲状腺结节的临床分析

目的:研究分析中国东北地区慢性淋巴细胞性甲状腺炎(CLT)合并甲状腺结节的诊断和治疗方式.方法:回顾性分析2009年9月--2010年12月收治经病理证实的CLT合并甲状腺结节的共151病例,依据不同的病理类型分组,就临床特点、诊断和治疗进行比较.结果:CLT合并甲状腺乳头状癌组共58例,女性51例,男性7例,平均年龄37.5±4岁,平均病程18个月,28例为腺体内单发结节,病灶平均直径为0.9± 0.56 cm,36例病灶直径小于1.0 cm,42例见结节内伴钙化.CLT合并良性结节组98例,女性患者93例,男性患者5例,平均年龄48.1±9岁,平均病程72个月,34例为腺体内单发结节,病灶平均直径1.8± 0.42 cm,35例病灶直径小于1.0 cm,10例见结节内伴钙化.两组在发病年龄、病程、结节个数及钙化方面的差异均有统计学意义.结论:CLT合并甲状腺癌微小癌多见,淋巴结转移率低,彩超提示单发结节或者结节合并钙化的病例,应行手术治疗.     

Inflammatory Lesions of the Breast: Diagnosis By Fine Needle Aspiration

Amongst 1061 breast lesions diagnosed by fine needle aspiration (FNA) over a period of 6 years (1985-1990), 128 were reported to be showing changes consistent with an inflammatory lesion. On review, the cytodiagnosis was found to be inaccurate in 31 cases. The cytological features of the 97 cases that were correctly reported are described in this report. The cytological diagnoses issued in these 97 cases were acute mastitis or breast abscess (57 cases) and tuberculous mastitis (30 cases). Non-specific chronic mastitis and miscellaneous conditions accounted for four and six cases respectively. Acid fast bacilli (AFB) were demonstrated in 28.0% of tuberculous mastitis cases and 10.0% of those diagnosed as acute mastitis or breast abscess. FNA cytology was found to be useful for the diagnosis of inflammatory lesions of breast and their classification, as only five out of 57 cases of acute mastitis/breast abscess and one out of 30 tuberculous mastitis cases were suspected on clinical grounds.     

Histological, clinical and laboratory findings of acute exacerbation of Hashimoto's thyroiditis--comparison with those of subacute granulomatous thyroiditis

As reported previously, acute exacerbation of Hashimoto's thyroiditis shows quite unique histological findings, namely localized edematous inflammation. Similar histological characteristics and clinical manifestations were observed in 7 of 492 patients with Hashimoto's thyroiditis (A group). Their clinical and laboratory findings were compared with those of 15 cases with subacute granulomatous thyroiditis (S group). Age and sex distribution and goiters in A group were 39 +/- 21 years old (mean +/- s.d.), 7/0 (F/M), and 6/1 (diffuse/nodular), respectively. These were somewhat different from those of S group (45 +/- 9, 12/3, and 3/12, respectively). Thyroid functions in A group showed wide variation: 3 cases were euthyroid, 2 were mildly hypothyroid, and one was mildly thyrotoxic and one borderline thyrotoxic, and all of the S group patients were thyrotoxic. Their thyroid radiopertechnetate uptake, scintigraphy, duration from the onset till the first visit, and ESR and CRP values were also different from those of S group. Clinical courses and outcomes of A group were generally favorable, but one of them finally underwent a total thyroidectomy. Per os and intrathyroidal administrations of steroid were effective, but there was observed a recurrence of symptoms in 3 cases. Finally, all 6 cases were left with diffuse goiters, 4 of them remaining euthyroid, and 2 falling into hypothyroidism. The acute exacerbation of Hashimoto's thyroiditis is a rare complication, which is found to be different from subacute thyroiditis on histological, clinical and laboratory findings and is generally subtle. Steroid medication is considered to be the therapeutic choice but careful observation is necessary to avoid a recurrence.