The relationship between positron emission tomography-computed tomography imaging and histopathological features of thyroid incidentalomas detected during follow-up for primary malignancy

Aim of the Study: While the rate of thyroid incidentaloma detected on positron emission tomography (PET) was reported as 4%, the malignancy rate was 14%–50%. We evaluated the thyroid nodules which were detected by PET-computerized tomography (CT) in cancer patients and analyzed the pathological results of those thyroid nodules diagnosed by fine needle aspiration biopsy (FNAB) and their correlation with the maximum standardized uptake (SUVmax) value and PET imaging features. Materials and Methods: FNAB were performed for 40 thyroid incidentalomas. We analyzed the relationship between the histopathological findings and radiological features by Pearson's correlations and Chi-square-Fisher's exact tests to evaluate the factors associated with SUVmax. Results: The median SUVmax values were 5.4 for thyroid nodules. Totally, 14 malignancies were detected by FNAB (35%).The sensitivity and specificity of SUVmax value for diagnosis of malignancy were 87.5% and 52%, respectively. Positive and negative predictive values were 36.8% and 92.8%. The most common malignant and benign pathologies were classic variant papillary carcinoma and benign colloidal nodule. The median SUVmax was the higher in colon cancer thyroid metastasis and oncocytic neoplasia (SUVmax 14.5 and 13.6, respectively). Histopathological type was not related with nodule size but positively associated with categorical SUVmax(r = 0.318, P = 0.04) and negatively correlated with both the density of the thyroid nodule in PET-CT (r = −0.0042, P = 0.01) and density of nodule in ultrasound (USG) (r = −0.305, P = 0.05). Margin of the thyroid nodule in USG (P = 0.007) and internal component of the nodule in PET (P = 0.03) were found to be important factors to differentiate benign or malignant lesion. Conclusion: If the thyroid nodule is detected with flouro-2-deoxy-D-glucose uptake, to differentiate benign nodule from malignant, cytological examination is noteworthy to diagnose the more aggressive type of thyroid nodule and also thyroid metastasis from primary cancer

Diagnostic Value of Volume-Based Fluorine-18-Fluorodeoxyglucose PET/CT Parameters for Characterizing Thyroid Incidentaloma

OBJECTIVE: To assess clinical value of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for differentiation of malignant from benign focal thyroid incidentaloma. MATERIALS AND METHODS: This retrospective study included 99 patients with focal thyroid incidentaloma of 5216 non-thyroid cancer patients that had undergone PET/CT. PET/CT semi-quantitative parameters, volume-based functional parameters, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of thyroid incidentaloma were assessed. Receiver-operating characteristic (ROC) analysis was conducted and areas under the curve (AUC) were compared by Hanley and McNeil test to evaluate usefulness of maximum standardized uptake value (SUVmax), MTV and TLG, as markers for differentiating malignant from benign thyroid incidentalomas. RESULTS: Of 99 thyroid incidentalomas, 64 (64.6%) were malignant and 35 (35.4%) were benign. Malignant thyroid incidentalomas were larger (1.8 cm vs. 1.3 cm, p = 0.006), and had higher SUVmax (11.3 vs. 4.8, p 0.05). A threshold TLG 4.0 of 2.475 had 81.3% sensitivity and 94.3% specificity for identifying malignant thyroid incidentalomas. CONCLUSION: Volume-based PET/CT parameters could potentially have clinical value in differential diagnosis of thyroid incidentaloma along with SUVmax.

Positron emission tomography thyroid incidentaloma: Is it different in Indian subcontinent.

BACKGROUND: Positron emission tomography (PET) forms an integral part in work‑up and follow‑up of various malignancies. With the increased use of PET in oncology, finding of an incidental focal thyroid uptake (incidentaloma) is not unusual and presents a diagnostic challenge. AIM: The aim of the following study is to evaluate the frequency and radio‑pathologic correlation of focal 18‑fluoro deoxyglucose uptake (FDG) on PET within the thyroid from a large series. MATERIALS AND METHODS: Retrospective review of 37,000 consecutive patients who underwent FDG‑PET at tertiary cancer center in India. Radiological, pathological, PET scan and follow‑up details were evaluated. Statistical analyzes were carried out using Mann Whitney test and Pearson correlation. RESULTS: Abnormal thyroid uptake was seen in 78 (0.2%) patients. Nearly 61 (0.16%) scans had focal and 17 (0.04%) had diffuse FDG uptake. A total of 57 patients with focal uptake were available for further evaluation. No further evaluation was done in 24 (42.1%) patients who had advanced index malignancy. Of the remaining 33 patients 26 were benign and seven were a cause for concern (four primary thyroid cancers, one follicular neoplasm with hurthle cell change and two metastatic cancers). There was no significant correlation in Standardized uptake value (SUV) max of benign and malignant lesion (P = 0.5 on Mann Whitney) or size (r = 0.087 Pearson correlation co‑efficient P = 0.667). CONCLUSION: Incidence of PET incidentaloma is low in this large cohort of Indian patients. Nearly 27% of focal incidentaloma were malignant. There was no correlation between the SUVmax, size and malignancy.

Angiosarcoma primario de mama y carcinoma papilar de tiroides sincrónico: presentación de un caso / Primary angiosarcoma of breast and synchronous thyroid papillary carcinoma: a case report

Antecedentes: El angiosarcoma primario de mama constituye un tumor infrecuente que se desarrolla de forma predominante en mujeres en la tercera y cuarta décadas de la vida. Los nódulos tiroideos incidentales son aquellos que se objetivan en pruebas de imagen realizadas por otra causa y se observan en menos de un 10 por ciento con la tomografía por emisión de positrones (PET). Objetivo: Presentar el caso excepcional de una paciente con angiosarcoma primario de mama y un carcinoma papilar de tiroides sincrónicos. Caso clínico: Mujer de 34 años con angiosarcoma primario en la mama derecha sometida a mastectomía simple. En el estudio de extensión se halló un incidentaloma tiroideo derecho compatible con carcinoma papilar que requirió tiroidectomía total y linfadenectomía del compartimento central cervical en un segundo tiempo. Comentarlo: Los angiosarcomas primarios suponen menos del 0,05 por ciento de todos los tumores primarios malignos de la mama. El diagnóstico definitivo de estos tumores viene definido por el estudio anatomopatológico, que establece tres grados: alto, bajo e intermedio, los cuales se relacionan de forma directa con la supervivencia. La prevalencia de los incidentalomas malignos tiroideos objetivados por PET varía del 14-30,9 por ciento, según diferentes estudios. La planificación del tratamiento quirúrgico de las neoplasias incidentales tiroideas en pacientes con otro tumor primario debe analizarse de forma individualizada, según la supervivencia esperada del tumor primario.

Background: The primary angiosarcoma of breast is a rare tumor that develops predominantly in women in the third and fourth decades of life. Incidental thyroid nodules are observed in imaging tests performed for other reasons and it's observed in less than 10 percent with the positron emission tomography (PET). Aims: To report the exceptional case of a patient with primary angiosarcoma of the breast and synchronous thyroid papillary carcinoma. Clinical case: Female patient 34 year old with primary angiosarcoma in the right breast, submitted to a simple mastectomy. In the extension study we found an incidental thyroid papillary carcinoma that required a total thyroidectomy and central cervical lymphadenectomy in a second time. Comments: The primary angiosarcoma are less than 0.05 percent of all primary malignant tumors of the breast. The definitive diagnosis is determined by the pathology, which defines three grades: high, low and intermediate, which relate directly to survival. Prevalence of malignant thyroid incidentalomas observed by PET varies from 14 to 30.9 percent, according different studies. Planning the surgical treatment of incidental thyroid malignancies in patients with other primary tumor should be analyzed individually, according the expected survival of the primary tumor.

Screening of Thyroid Cancer and Management of Thyroid Incidentaloma / 가정의학회지

Increasing thyroid cancer incidence is due to the increased detection of small papillary cancers and may not interpreted as an increase in the true occurrence of disease. Further workup of thyroid incidentalomas-impalpable nodules detected fortuitously during a radiological investigation-may contribution of the increasing thyroid cancer. Screening asymptomatic adults or children for thyroid cancer using either neck palpation or ultrasonography is not recommended in the US Preventive Services Task Force and the Korean lifetime health maintenance program. Generally, only thyroid incidentalomas > 1 cm should be evaluated, since they have a greater potential to be clinically significant cancers and thyroid nodules < 1 cm that require evaluation because of suspicious US findings, associated lymphadenopathy, a history of head and neck irradiation, or a history of thyroid cancer in one or more first-degree relatives.

18F-FDG PET/CT and Sonographic Findings of Thyroid Incidentalomas

PURPOSE: To compare characteristic findings of 18F-FDG PET/CT with ultrasonography of malignant thyroid incidentaloma. MATERIALS AND METHODS: This study enrolled 74 patients receiving ultrasonography after thyroid incidentaloma detected on 18F-FDG PET/CT. We analyzed the size, attenuation, margin, cervical lymphadenopathy, and P-SUV of thyroid incidentaloma in 18F-FDG PET/CT and analyzed the size, internal contents, appearance, border, echo, and calcification patterns of thyroid incidentaloma in ultrasonography. Based on pathologic findings, we investigated findings of 18F-FDG PET/CT and ultrasonography for malignant thyroid incidentaloma. RESULTS: In 18F-FDG PET/CT findings, an ill-defined margin accompanied by cervical lymphadenopathy was more common in malignant (59.1%) than benign (13.2%) lesions (p < 0.05). There were no significant differences in p-SUV between malignant and benign thyroid incidentalomas (4.8+/-18.3 vs. 4.4+/-2.2). In ultrasonographic findings, being taller than wide (1.9% vs. 36.4%), having a well-defined speculated margin (75.5% vs. 22.7%), having marked hypoechoic images (18.9% vs. 31.8%), and having micro (5.7% vs. 22.7%) or macrocalcifications (3.8% vs. 27.3%) were more common in malignant thyroid incidentalomas (p < 0.05). CONCLUSION: Malignant thyroid incidentalomas in 18F-FDG PET/CT have ill-defined margins, and those in ultrasonography were the taller than wide, well defined spiculated margin, and showed micro or macrocalcification.

A Clinical Analysis of Surgical Treated Thyroid Incidentaloma / 대한내분비외과학회지

PURPOSE: An incidentaloma is a tumor that is found incidentally without clinical symptoms. This study was carried out to evaluate the clinicopathologic characteristics and to offer the optimal diagnostic and therapeutic strategies for surgical treated thyroid incidentaloma. METHODS: We reviewed the medical records of 139 consecutive patients who were operated on for incidentally detected thyroid nodules from January 2000 to June 2005, and we retrospectively investigated the clinicopathologic characteristics, preoperative diagnostic methods, operative methods and histologic diagnosis of surgical treated thyroid incidentaloma. RESULTS: The male-to-female ratio was 1:9.7 (13:126) and the mean age was 45.8 years. The mean tumor size was 1.27 cm and 122 cases (87.8%) were 1.5 cm or less in diameter. 138 patients underwent ultrasonography and 34 patients (24.6%) were diagnosed with malignant nodules. US-guided fine needle aspiration cytology (FNAC) was performed in 118 patients and 42 patients (35.6%) were diagnosed with papillary carcinoma. According to postoperative histologic diagnosis, 70 cases (50.3%) were adenomatous goiter, 14 cases (10.2%) were follicular adenoma and 54 cases (38.8%) were papillary carcinoma. Among the papillary carcinoma, capsular invasion were presented in 3 cases (5.6%) and lymph node metastasis were presented in 5 cases (9.3%). According to the TNM staging, 33 cases (61.1%) were stage I, 16 cases (29.6%) were stage II, and 5 cases (9.3%) were stage? By the AMES scoring system, 2 cases (3.7%) were in the high risk group. CONCLUSION: Although most patients with incidental thyroid carcinomas were low stage, their clinicopathologic characteristics were similar to those of general thyroid carcinoma. Therefore, high risk patients with thyroid incidentaloma should have active diagnostic methods performed such as FNAC for confirming the presence of carcinoma.