Coexistence of Papillary Thyroid Cancer and Hashimoto Thyroiditis in Children

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1 CSE SERIES Coexistence of Papillary Thyroid Cancer and Hashimoto Thyroiditis in Children Report of 3 Cases Harumi Koibuchi, MD, PhD, Kiyoka Omoto, MD, PhD, Noriyoshi Fukushima, MD, PhD, Tomonori Toyotsuji, MD, Nobuyuki Taniguchi, MD, PhD, Mikihiko Kawano, MD, PhD This report documents 3 pediatric papillary thyroid carcinoma cases with associated Hashimoto thyroiditis. In all 3 cases, hypoechoic nodules accompanied by multiple echogenic spots were noted on sonography of the thyroid. Hashimoto thyroiditis was suspected on the basis of positive thyroid autoantibody test results and pathologic examinations of thyroidectomy specimens, which revealed chronic thyroiditis with lymphocytic infiltration as the background of papillary thyroid carcinoma development. The potential for papillary carcinoma development warrants close follow-up, and meticulous sonographic examinations must be performed in children with Hashimoto thyroiditis. Key Words children; fine-needle aspiration; Hashimoto thyroiditis; papillary thyroid carcinoma; sonography; superficial structures Received ugust 7, 2013, from the Departments of Clinical Laboratory Medicine (H.K., K.O., T.T., N.T., M.K.) and Laboratory Medicine (K.O., M.K.), Saitama Medical Center, and Department of Diagnostic Pathology (N.F., T.T.), Jichi Medical University, Saitama, Japan. Revision requested ugust 22, Revised manuscript accepted for publication October 21, ddress correspondence to Kiyoka Omoto, MD, PhD, Department of Laboratory Medicine, Saitama Medical Center, Jichi Medical University, manuma-cho, Omiya-ku, Saitama , Japan. kiyoka@jichi.ac.jp doi: /ultra Thyroid cancer occurs most frequently in adults, with patients 20 years or younger accounting for only about 2.75% of all patients with thyroid cancer. 1 In patients 20 years or younger, 83% of thyroid cancers have been reported to be papillary carcinomas histologically. 2 The incidence of papillary carcinoma is reportedly increased in patients with Hashimoto thyroiditis. 3 6 Retrospective studies have also shown patients with histologically diagnosed Hashimoto thyroiditis to have a high risk of developing papillary carcinoma. 7 9 There are many reports of adult papillary carcinoma cases with Hashimoto thyroiditis but few articles describing pediatric cases. 10,11 Moreover, there are no reports presenting sonograms and their associated findings in children. We have had 3 relatively rare pediatric papillary thyroid carcinoma cases with Hashimoto thyroiditis as a comorbidity. We document those cases here with primary reference to the sonographic findings by the merican Institute of Ultrasound in Medicine J Ultrasound Med 2014; 33:

2 Case Descriptions Case 1 13-year-old girl who had been noted to have a goiter at school health screening was subsequently examined at a nearby medical clinic, where chronic thyroiditis was suspected on the basis of the following laboratory findings: thyrotropin, 1.88 μu/ml; free thyroxine, 0.98 ng/dl; free triiodothyronine, 2.93 pg/ml; thyroid test, 6400 ; microsome test, 1600 ; and anti-thyrotropin receptor antibody, 0%. The patient was referred to us for further examinations, and sonography revealed a mm hypoechoic nodule with multiple echogenic spots in the right lobe (Figure 1). s the patient was reluctant to undergo fine-needle aspiration and because the lesion was small, she was followed with periodic checkups. On follow-up sonography 9 months later, the nodule had increased in size to mm with conspicuous marginal hyperechoic areas (Figure 1, and C). Since malignancy was strongly suspected, fine-needle aspiration was performed with the patient s consent. Pathologic results indicated that the lesion was positive for malignant cells: ie, class V. The patient underwent total thyroidectomy, and papillary thyroid carcinoma with lymph node metastasis was diagnosed. The background thyroid tissues showed evidence of chronic thyroiditis, and psammoma bodies were noted in the tumor. Case 2 14-year-old girl who had been noted to have a goiter during school health screening was referred to us for detailed examinations. Laboratory tests disclosed the following findings: thyrotropin, 1.62 μu/ml; free thyroxine, 1.04 ng/dl; free triiodothyronine, 2.46 pg/ml; and microsome test, Therefore, chronic thyroiditis was suspected. Sonography of the neck revealed a poorly defined, irregularly shaped hypoechoic area with a major axis of approximately 3 cm, with marginal faint hyperechoic dots in the right lobe of the thyroid (Figure 2, and ). Color Doppler imaging showed abundant blood flow signals within the hypoechoic area (Figure 2C). s an oval lymph node indicative of metastasis was noted in the right cervical region, fine-needle aspiration of the hypoechoic area was performed with the patient s consent. Pathologic examination of an aspirated cytologic specimen indicated that the lesion was class V, suggesting papillary carcinoma. The patient underwent subtotal thyroidectomy and right-sided lymphadenectomy. Papillary thyroid carcinoma was diagnosed by examination of the resected thyroid, which showed areas of admixed, poorly differentiated Figure 1. Case 1: 13-year-old girl with papillary thyroid carcinoma associated with Hashimoto thyroiditis., On a long-axis view of the right thyroid lobe, a mm hypoechoic nodule (arrowheads) accompanied by marginal echogenic spots (arrows) was shown. and C, Long-axis () and transverse (C) sonograms taken 9 months later revealed the nodule to have enlarged to mm with an increased area ratio of the marginal hyperechoic region (arrows). C 1300 J Ultrasound Med 2014; 33:

3 Figure 2. Case 2: 14-year-old girl with papillary thyroid carcinoma associated with Hashimoto thyroiditis. and, Long-axis () and transverse () sonograms showed a poorly defined, irregularly shaped hypoechoic area (arrowheads) with a major axis of approximately 3 cm, with marginal faint punctate high echoes (arrows) in the right lobe of the thyroid. C, Color Doppler imaging showed abundant pulsating blood flow signals within the hypoechoic area. carcinoma with evidence of lymph node metastasis. Numerous fine calcifications were present within the tumor, and the background thyroid tissue showed evidence of chronic thyroiditis. Case 3 The patient had been noted to have swelling of the anterior region of the neck at 8 years of age, and Hashimoto thyroiditis was diagnosed at a neighborhood clinic at 10 years. The patient was referred to us for a full medical workup at 12 years and underwent a sonographic examination. Sonography of the neck revealed a mm hypo - echoic nodule with numerous marginal echogenic spots in the left lobe (Figure 3). There was no cervical lymph node enlargement. Figure 3. Case 3: 12-year-old girl with papillary thyroid carcinoma associated with Hashimoto thyroiditis. and, Long-axis () and transverse () sonograms showed a mm hypoechoic nodule (arrowheads) with numerous marginal echogenic spots (arrows) in the left lobe. C J Ultrasound Med 2014; 33:

4 Fine-needle aspiration of the nodule in the left lobe was performed with the patient s consent, and the lesion was found to be class IV pathologically, although the diagnosis of papillary carcinoma was inconclusive. s a second fine-needle aspiration was declined, we followed this patient with periodic checkups. One year later, when the patient was 13 years old, follow-up sonographic findings, including nodule size, were essentially the same as before. The patient refused fine-needle aspiration, but thyroidectomy under general anesthesia was performed after consultation with her parents. The tumor was diagnosed as papillary carcinoma (encapsulated type) based on the pathologic findings of the resected tissue specimens, and the background thyroid tissue showed chronic thyroiditis. Discussion Most thyroid cancers are papillary carcinomas pathologically, not only in adults but also in children. Interestingly, in our series, all 3 pediatric cases had Hashimoto thyroiditis as a background characteristic. Papillary carcinoma has a higher incidence in patients with positive thyroid autoantibody test results than in those with negative results, according to a report by Ohmori et al. 3 Mukasa et al 4 documented that concurrent thyroid cancer was more frequent in patients with Hashimoto thyroiditis than in those with asedow disease. Three retrospective studies investigating resected thyroid nodules showed the incidence of papillary carcinoma with histologically diagnosed Hashimoto thyroiditis to be relatively high. 7 9 Meanwhile, another study demonstrated that there was no statistically significant relationship between chronic thyroiditis and the occurrence of papillary thyroid carcinoma. 12 Papillary thyroid carcinoma was noted in 11 (3.0%) of 365 children with chronic thyroiditis according to a report by Corrias et al 10 and in 3 (1.3%) of 228 children with chronic thyroiditis according to Skarpa et al. 11 However, to our knowledge, no studies have presented sonograms and associated findings of pediatric papillary thyroid carcinoma cases with Hashimoto thyroiditis. Radiation is widely recognized as a risk factor for papillary thyroid carcinoma, but none of our cases had any history of radiation exposure. Papillary thyroid carcinomas are characterized sonographically by irregularly shaped hypoechoic nodules with multiple hyperechoic spots suggestive of psammoma bodies, which often provide a clue to the diagnosis. In case 1, a well-defined hypoechoic nodule with marginal punctate echoes was initially observed (Figure 1), but 9 months later, this nodule had an irregular contour (Figure 1, and C). In case 2, the lesion was poorly demarcated, presenting irregularly shaped hypoechoic areas with marginal hyperechoic dots (Figure 2, and ). The hypoechoic nodule in case 3 was relatively regular in shape with marginal echogenic spots (Figure 3). The small nodules in cases 1 and 3 were relatively regular in shape, whereas the nodules in case 2 and, after enlargement, that in case 1 all became irregular in shape. The nodules in all 3 cases had numerous echogenic spots, and this morphologic feature is considered an important finding for making a diagnosis of papillary carcinoma in children. Gharib et al 16 reported that when a thyroid tumor was solid and larger than 1 cm, fineneedle aspiration was recommended. In our cases 2 and 3, because the nodules exceeded 1 cm, and in case 1, the tumor size grew larger than 1 cm, fine-needle aspiration was performed. There are reports demonstrating the usefulness of fine-needle aspiration in diagnosing thyroid cancer in children, as in adult patients, 10,17 and our experience in this series also supports the utility of fineneedle aspiration. This cytodiagnostic procedure yielded pathologic findings suggesting class IV malignancy and papillary carcinoma. limitation of this series was that the assessments were made in patients with goiters identified during school health screening or under other incidental circumstances, such that the data cannot be said to reflect the frequency with which papillary thyroid carcinoma or Hashimoto thyroiditis occurs in the overall pediatric population. We initially thought that a diagnosis of malignancy would have to be made without delay because of the suspicion of papillary carcinoma in cases in which sonography of the neck revealed an irregularly shaped hypoechoic nodule with echogenic dots or spots. However, even a very young child may refuse exploratory fine-needle aspiration because it is a painful procedure. Therefore, physicians should use discretion in deciding whether fine-needle aspiration is to be undertaken. However, if the lesion tends to increase in size, or if lymph node metastasis is suspected, surgical excision under general anesthesia should be considered, with informed consent from the patient s family. There was pathologic evidence of Hashimoto thyroiditis as a background comorbidity in our cases, but as it was difficult to diagnose Hashimoto thyroiditis solely on the basis of sonographic findings: we considered it necessary to obtain a serologic diagnosis in these pediatric cases. Further study involving more cases is needed to assess the incidence and sonographic findings of papillary thyroid carcinoma with Hashimoto thyroiditis J Ultrasound Med 2014; 33:

5 lthough it is difficult to diagnose Hashimoto thyroiditis by sonography in pediatric patients, we advocate actively performing sonography of the thyroid in cases with suspected Hashimoto thyroiditis based on blood tests for thyroid hormones, thyroid autoantibodies, and other indicators. If an irregularly shaped hypoechoic nodule with marginal echogenic spots indicative of microcalcifications is discovered, probable papillary thyroid carcinoma associated with Hashimoto thyroiditis should be considered, and the diagnosis should be established by performing fineneedle aspiration. References 1. Luster M, Lassmann M, Freudenberg LS, Reiners C. Thyroid cancer in childhood: management strategy, including dosimetry and long-term results. Hormones (thens) 2007; Hogan R, Zhuge Y, Perez E, Koniaris LG, Lew JI, Sola JE. Pediatric thyroid carcinoma: incidence and outcomes in 1753 patients. J Surg Res 2009; 156: Ohmori N, Miyakawa M, Ohmori K, Takano K. Ultrasonographic findings of papillary thyroid carcinoma with Hashimoto s thyroiditis. Intern Med 2007; 46: Mukasa K, Noh JY, Kunii Y, et al. Prevalence of malignant tumors and adenomatous lesions detected by ultrasonographic screening in patients with autoimmune thyroid diseases. Thyroid 2010; 21: Gul K, Dirikoc, Kiyak G, et al. The association between thyroid carcinoma and Hashimoto s thyroiditis: the ultrasonographic and histopathologic characteristics of malignant nodules. Thyroid 2010; 20: Consorti F, Loponte M, Milazzo F, Potasso L. ntonaci. Risk of malignancy from thyroid nodular disease as an element of clinical management of patients with Hashimoto s thyroiditis. Eur Surg Res 2010; 45: Dailey ME, Lindsay S, Skahen R. Relation of thyroid neoplasms to Hashimoto disease of the thyroid gland. M rch Surg 1955; 70: Hirabayashi RN, Lindsay S. The relation of thyroid carcinoma and chronic thyroiditis. Surg Gynecol Obstet 1965; 121: Ott R, McCall R, McHenry C, et al. The incidence of thyroid carcinoma in Hashimoto s thyroiditis. m Surg 1987; 53: Corrias, Cassio, Weber G, et al. Thyroid nodules and cancer in children and adolescents affected by autoimmune thyroiditis. rch Pediatr dolesc Med 2008; 162: Skarpa V, Kousta E, Tertipi, et al. Epidemiological characteristics of children with autoimmune thyroid disease. Hormones 2011; 10: Matesa-nić D, Matesa N, Dabelić N, Kusić Z. Coexistence of papillary carcinoma and Hashimoto s thyroiditis. cta Clin Croat 2009; 48: Thompson DE, Mabuchi K, Ron E, et al. Cancer incidence in atomic bomb survivors, part II: solid tumors, Radiat Res 1994; 137(suppl):S17 S Imaizumi M, Usa T, Tominaga T, et al. Radiation dose-response relationships for thyroid nodules and autoimmune thyroid diseases in Hiroshima and Nagasaki atomic bomb survivors years after radiation exposure. JM 2006; 295: Tronko MD, Howe GR, ogdanova TI, et al. cohort study of thyroid cancer and other thyroid diseases after the Chernobyl accident: thyroid cancer in Ukraine detected during first screening. J Natl Cancer Inst2006; 98: Gharib H, Papini E, Paschke R, et al. merican ssociation of Clinical Endocrinologists, ssociazione Medici Endocrinologi, and European Thyroid ssociation medical guidelines for clinical practice for the diagnosis and management of thyroid nodules. Endocr Pract 2010; 16(suppl 1): argren E, Meyer-Rochow GY, Sywak MS, Delbridge LW, Chen H, Sidhu S. Diagnostic utility of fine-needle aspiration cytology in pediatric differentiated thyroid cancer. World J Surg 2010; 34: J Ultrasound Med 2014; 33: