Can Ethanol Ablation Achieve Durable Control of Neck Nodal Recurrences in Adults With Stage I Papillary Thyroid Cancer?

Objective: Results of ethanol ablation (EA) for controlling neck nodal metastases (NNM) in adult patients with papillary thyroid carcinoma (APTC) beyond 6 months have rarely been reported. We now describe outcome results in controlling 71 NNM in 40 node-positive stage I APTC patients followed for 66 to 269 months. Methods: All 40 patients were managed with bilateral thyroidectomy and radioiodine therapy and followed with neck ultrasound (US) for >48 months after EA. Cumulative radioiodine doses ranged from 30 to 550 mCi; pre-EA 27 patients (67%) had 36 additional neck surgeries. Cytologic diagnosis of PTC in 71 NNM selected for EA was confirmed by US-guided biopsy. EA technique and follow-up protocol were as previously described. Results: The 40 patients had 1 to 4 NNM; 67/71 NNM (94%) received 2 to 4 ethanol injections (total median volume 0.8 cc). All ablated 71 NNM shrank (mean volume reduction of 93%); nodal hypervascularity was eliminated. Thirty-eight NNM (54%) with initial volumes of 12-1404 mm3 (median 164) disappeared on neck sonography. Thirty-three hypovascular foci from ablated NNM (pre-EA volume range 31-636 mm3; median 147) were still identifiable with volume reductions of 45% to 97% observed (median 81%). There were no complications and no postprocedure hoarseness. Final results were considered to be ideal or near ideal in 55% and satisfactory in 45%. There was no evidence of tumor regrowth after EA. Conclusion: Our results demonstrate that for patients with American Joint Committee on Cancer stage I APTC, who do not wish further surgery or radioiodine, and are uncomfortable with active surveillance, EA can achieve durable control of recurrent NNM.

Long-Term Results of Treating With Ethanol Ablation 15 Adult Patients With cT1aN0 Papillary Thyroid Microcarcinoma.

BACKGROUND: Currently acceptable management options for patients with adult papillary thyroid microcarcinoma (APTM) range from immediate surgery, either unilateral lobectomy or bilateral lobar resection, to active surveillance (AS). An alternative minimally invasive approach, originally employed for eliminating neck nodal metastases, may be ultrasound-guided percutaneous ethanol ablation (EA). Here we present our experience of definitively treating with EA 15 patients with APTM. PATIENTS AND METHODS: During 2010 through 2017, the 15 cT1aN0M0 patients selected for EA were aged 36 to 86 years (median, 45 years). Tumor volumes (n = 17), assessed by sonography, ranged from 25 to 375 mm3 (median, 109 mm3). Fourteen of 15 patients had 2 ethanol injections on successive days; total volume injected ranged from 0.45 to 1.80 cc (median, 1.1 cc). All ablated patients were followed with sonography and underwent recalculation of tumor volume and reassessment of tumor perfusion at each follow-up visit. RESULTS: The ablated patients have now been followed for 10 to 100 months (median, 64 months). There were no complications and no ablated patient developed postprocedure recurrent laryngeal nerve dysfunction. All 17 ablated tumors shrank (median 93%) and Doppler flow eliminated. Median tumor volume reduction in 9 identifiable avascular foci was 82% (range, 26%-93%). After EA, 8 tumors (47%) disappeared on sonography after a median of 10 months. During follow-up no new PTM foci and no nodal metastases have been identified. CONCLUSIONS: Definitive treatment of APTM by EA is effective, safe, and inexpensive. Our results suggest that, for APTM patients who do not wish neck surgery and are uncomfortable with AS, EA represents a well-tolerated and minimally invasive outpatient management option.

Image-guided tumor ablation: standardization of terminology and reporting criteria--a 10-year update.

Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes.

Image-guided tumor ablation: standardization of terminology and reporting criteria--a 10-year update.

Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes. Online supplemental material is available for this article .

Long-term outcome of ultrasound-guided percutaneous ethanol ablation of selected "recurrent" neck nodal metastases in 25 patients with TNM stages III or IVA papillary thyroid carcinoma previously treated by surgery and 131I therapy.

BACKGROUND: Ultrasound-guided percutaneous ethanol ablation (UPEA) of neck nodal metastases (NNM) has rarely been reported in papillary thyroid carcinoma (PTC) patients with advanced localized disease. METHODS: We ablated 25 PTC patients with stage III or IVA disease (mean age 58 years) who had "recurrent" NNM after surgery and 131I therapy. Diagnosis of 37 selected NNM was proven by ultrasound-guided biopsy. UPEA was usually performed in 2 outpatient sessions. RESULTS: After UPEA, 35 of 37 NNM (95%) decreased in size. None had significant Doppler flow. Seventeen (46%) disappeared on rescanning. Serum thyroglobulin fell in 19 of 22 (86%) without thyroglobulin autoantibodies. None of the UPEA-treated NNM, followed on average for 5.4 years, required further intervention. Six patients (24%) subsequently developed 18 "new" recurrences. Of the 18, 15 (83%) were managed successfully by UPEA rather than operation. None of the 25 patients developed permanent hoarseness or have died from PTC. At our institution, where patients undergoing nodal dissections are charged $35-45,000, each outpatient UPEA procedure saves health providers approximately $38,400. Our 25 ablated patients, by avoiding 40 further neck reexplorations, on average, saved $61,440 in charges. CONCLUSION: UPEA for NNM in advanced localized PTC has proved safe and effective. It is also considerably less expensive than the conventional operative alternative of nodal dissection.

Percutaneous image-guided cryoablation of painful metastases involving bone: multicenter trial.

BACKGROUND: This study sought to describe the results of a single-arm multicenter clinical trial using image-guided percutaneous cryoablation for the palliation of painful metastatic tumors involving bone. METHODS: Over a 44-month period, 61 adult patients with 1 or 2 painful bone metastases with a score of 4 or more on a scale of 0 to 10 (≥4/10) worst pain in a 24-hour period who had failed or refused conventional treatment were treated with percutaneous image-guided cryoablation. Patient pain and quality of life was measured using the Brief Pain Inventory prior to treatment, 1 and 4 days after the procedure, weekly for 4 weeks, and every 2 weeks thereafter for a total of 6 months. Patient analgesic use was also recorded at these same follow-up intervals. Complications were monitored. Analysis of the primary endpoint was undertaken via paired comparison procedures. RESULTS: A total of 69 treated tumors ranged in size from 1 to 11 cm. Prior to cryoablation, the mean score for worst pain in a 24-hour period was 7.1/10 with a range of 4/10 to 10/10. At 1, 4, 8, and 24 weeks after treatment, the mean score for worst pain in a 24-hour period decreased to 5.1/10 (P < .0001), 4.0/10 (P < .0001), 3.6/10 (P < .0001), and 1.4/10 (P < .0001), respectively. One of 61 (2%) patients had a major complication with osteomyelitis at the site of ablation. CONCLUSIONS: Percutaneous cryoablation is a safe, effective, and durable method for palliation of pain due to metastatic disease involving bone.

Percutaneous image-guided adrenal cryoablation: procedural considerations and technical success.

PURPOSE: To assess safety, technical success, complications, and hemodynamic changes associated with the adrenal cryoablation procedure. MATERIALS AND METHODS: This retrospective review was approved by the institutional review board, with waiver of informed consent, and was compliant with the Health Insurance Portability and Accountability Act. Adult patients with adrenal metastasis who were treated with adrenal cryoablation between May 2005 and October 2009 were eligible for this review. Twelve patients (undergoing 13 procedures) with single adrenal tumors were included in the analysis. For statistical analysis, hemodynamic data were averaged for the patient undergoing the procedure twice. Technical success, safety, and local control were analyzed according to standard criteria. Hemodynamic changes during the procedure were analyzed and compared with data from an unmatched cohort of patients who underwent kidney (not in the upper pole) cryoablation (Wilcoxon rank sum test). A further subanalysis of hemodynamic changes was performed on the basis of whether preprocedural α- or ß-adrenergic blockade was used. RESULTS: With adrenal cryoablation, local control was achieved following treatment in 11 (92%; 95% confidence interval: 65.1%, 99.6%) of 12 tumors. One patient with known adrenal insufficiency underwent conservative ablation and developed ipsilateral adrenal recurrence, which was retreated. Five patients developed hypertensive crisis during the final, active thaw phase of the cryoablation procedure, and one patient developed hypertensive crisis in the immediate postablation period. Patients undergoing adrenal cryoablation experienced a significant increase in systolic blood pressure (P = .005), pulse pressure (P = .02), and mean arterial pressure (P = .01) when compared with the cohort of kidney cryoablation patients. Adrenal cryoablation patients who were not premedicated with an α-blocker (n = 5) had a higher level of systolic blood pressure increase during the cryoablation procedure when compared with their counterparts who were premedicated (n = 7) (P = .034). CONCLUSION: Adrenal cryoablation is technically feasible with a high rate of local control. Patients premedicated with the α-blocker phenoxybenzamine appear to have a reduced risk of hypertensive crisis.

Percutaneous cryoablation of anterior renal masses: technique, efficacy, and safety.

OBJECTIVE: The safety and efficacy of renal tumor ablation are related, in part, to tumor location. Anterior tumors present a challenge due to the risk of injury to adjacent structures. The purpose of this study was to review the techniques, complications, and short-term outcomes of percutaneous cryoablation of anterior renal masses at a single institution. MATERIALS AND METHODS: We retrospectively identified the cases of 35 patients with 38 anterior renal masses managed with percutaneous imaging-guided cryoablation of renal tumors from March 2003 through February 2009. The technical success of the ablation procedure, serious complications, and evidence of local tumor recurrence were evaluated for each patient. RESULTS: The average maximal diameter of the anterior renal masses was 2.9 cm (SD, 0.9 cm; range, 1.4-4.8 cm). A single cryoablation procedure was performed for treatment of each patient, and technically successful ablation was achieved for all 38 tumors. A single severe adverse event occurred in one of the 35 patients (3% major complication rate). This patient had a pulmonary embolism (diagnosed at CT angiography the day after ablation). He recovered and was discharged from the hospital with anticoagulant medication only 2 days after the procedure. No local tumor recurrence was identified in any of the 29 patients who underwent follow-up contrast-enhanced CT or MRI with images available for review 3 months or longer from the time of ablation (mean, 18 months; range, 3-45 months). CONCLUSION: Percutaneous cryoablation of anterior renal masses can be performed with high technical success and low complication rates. The lack of local renal tumor recurrence at short-term follow-up evaluation in this study is encouraging, but long-term follow-up is necessary to ensure the durability of treatment.

Percutaneous renal cryoablation: local control at mean 26 months of followup.

PURPOSE: We retrospectively determined the efficacy of percutaneous renal cryoablation based on a mean followup of more than 2 years. MATERIALS AND METHODS: Institutional review board approval was obtained for this Health Insurance Portability and Accountability Act compliant retrospective study. Informed consent was waived. From March 2003 through March 2007, 91 patients with 93 tumors underwent 92 percutaneous cryoablation procedures. Technical success was defined as extension of the ice ball beyond the tumor margin and post-ablation images showing no contrast enhancement in the area encompassing the original tumor within 3 months of the procedure. Local tumor progression was defined as new enhancement in the ablated tumor or an increase in ablated tumor size beyond 3 months after the procedure. Complications were defined using the National Cancer Institute Common Terminology Criteria for Adverse Events v3.0. RESULTS: Mean followup was 26 months (range 5 to 61, SD ±13) and mean tumor size was 3.4 cm (range 1.5 to 7.3, SD ±1.2). Major complications occurred in 6 of 91 patients (7%) or after 8 of 92 (9%) procedures. Technically successful ablation was performed in the treatment of 89 of the 93 (96%) tumors or 87 of the 91 patients (96%). Of the 83 tumors with followup longer than 3 months only a single case (1%) of local tumor progression occurred. Overall local control was achieved in 86 of 91 (95%) patients or 88 of 93 (95%) tumors. CONCLUSIONS: Midterm followup of percutaneous renal cryoablation shows durability of this treatment method with a low incidence of tumor recurrence beyond 3 months.

Ice ball fractures during percutaneous renal cryoablation: risk factors and potential implications.

The authors present two cases of ice ball fractures with associated hemorrhage during percutaneous renal cryoablation procedures. Although this is a rare occurrence, it is important to be able to identify ice ball fractures on monitoring noncontrast computed tomography (CT) scans during cryoablation, because they can result in significant bleeding, and recognition allows prompt intervention. Risk factors for ice ball fractures and potential implications are discussed.

Cystic change in thyroid carcinoma: Prevalence and estimated volume in 360 carcinomas.

PURPOSE: The aim of this study was to determine the prevalence and amount of cystic change in thyroid cancer. This study also examined associated sonographic characteristics of cystic malignant thyroid nodules to help recognize these clinically important nodules. METHODS: This study was a retrospective review of 360 malignant thyroid nodules surgically removed at our institution between January 1, 2002 and December 31, 2004. All patients had signed research authorization. All patients had preoperative sonograms and surgical pathologic proof of their thyroid malignancy. The 360 malignant nodules were found in 307 patients. All scans were performed using 7- to 15-MHz transducers, and most studies included a digital video clip of the cancer. The preoperative ultrasound examinations were retrospectively reviewed by three radiologists and a sonographer. An estimate of cystic component percentage was derived by consensus. The presence of a mural nodule, thick irregular wall, microcalcifications, and prominent vascularity was also recorded. RESULTS: Of the 360 carcinomas, 318 (88.3%) were solid to minimally (less than 5%) cystic, 33 (9.2%) were 6-50% cystic, 9 (2.5%) were 51-100% cystic. Of the nine (2.5%) malignancies that were greater than 50% cystic, all had other suspicious findings including mural nodules, microcalcifications, increased vascularity, and/or a thick irregular wall about the cystic portion. CONCLUSION: The vast majority (88%) of thyroid cancer is uniformly solid or has minimal (1-5%) cystic change by sonography. Marked cystic change (>50% of the nodule) occurred in only 2.5% of cancers, which had other sonographic findings worrisome for malignancy.

Percutaneous cryoablation of masses in a solitary kidney.

OBJECTIVE: The purpose of this study was to determine the effect of percutaneous cryoablation of tumors in a solitary kidney on renal function, treatment-related complications, and local tumor control. MATERIALS AND METHODS: A retrospective review of the cases of patients with a solitary kidney treated with percutaneous renal cryoablation from March 2003 through November 2008 was performed. Renal function was analyzed with serum creatinine concentration and glomerular filtration rate measured before ablation, on the first day after ablation, 3-6 months after ablation, and at the most recent evaluation on record at our institution. Index tumor size, ice ball size, and local tumor control were tabulated after review of preablation and postablation images. RESULTS: Thirty-one patients with 38 tumors (mean maximum diameter, 3.0 cm; range, 1.7-7.3 cm) were treated with 35 cryoablation procedures. After a mean follow-up period of 14 months (range, < 1-42 months), 29 patients had a 0.1-mg/dL median increase in creatinine concentration (p = 0.0089) and 4.7-mL/min/1.73 m(2) median decrease in glomerular filtration rate (p = 0.0335) from preablation levels. Fifteen of 25 patients with 3 months or more of renal function follow-up had a decrease in renal function. Ten of these 15 patients (67%) had a history of previous renal ablation or partial nephrectomy involving the same solitary kidney. No patient needed dialysis. Seven grade 3 or greater complications (Common Terminology Criteria for Adverse Events) occurred after the 35 procedures (20% complication rate). The median hospital stay was 1 day (range, 1-19 days). The local tumor control rate was 92%. CONCLUSION: Percutaneous cryoablation is effective in the management of renal tumors in patients with a solitary kidney, causing minimal loss of renal function. Patients who have previously undergone partial nephrectomy or ablation in a solitary kidney may be more susceptible to renal function loss than patients who have not undergone these procedures.

Role of intraarterial embolization before cryoablation of large renal tumors: a pilot study.

A retrospective review of patients who underwent percutaneous cryoablations of renal tumors (> or = 5 cm) with/without previous selective intraarterial embolization from March 2003 to January 2008 was performed to compare periprocedural complications. Of 129 treated tumors, 11 (8.5%) were larger than 5 cm. One patient was lost to follow-up. Of the remaining 10 follow-up patients, four (40%) underwent selective intraarterial tumor embolization before cryoablation. The mean hematoma volume in patients who underwent embolization before cryoablation (n = 4) was 18.3 mL +/- 25.9, whereas that in patients who underwent cryoablation alone (n = 6) was 357.3 mL +/- 460.9 (P< .01). Only one patient required transfusion and prolonged hospitalization. Combination therapy can provide a decrease in postprocedural cryoablation-related hemorrhage.

Percutaneous cryoablation of renal masses >or=3 cm: efficacy and safety in treatment of 108 patients.

PURPOSE: To evaluate our single institution experience with percutaneous cryoablation of renal masses >or=3 cm in diameter for complications and short-term outcomes. PATIENTS AND METHODS: Between March 2003 and February 2009, 108 patients with 110 renal masses >or=3 cm in diameter were treated with percutaneous cryoablation therapy. Technical success of the ablation procedure, complications, and evidence for local tumor recurrence were evaluated for each patient. RESULTS: Average maximal renal tumor diameter was 4.1 cm (range 3.0-8.3 cm; standard deviation 1.1 cm). A single cryoablation procedure was performed for treatment of each patient. A technically successful ablation was achieved for 107 of 110 (97%) tumors. The three technical failures all resulted from incomplete cryoablation of the deepest margin of a centrally located renal tumor. A total of 9 severe adverse events occurred in six patients, resulting in an 8% major complication rate. Two patients in whom major complications developed were part of the group of only four patients for whom ablation was performed for tumors > 7 cm in diameter. There were no procedural-related deaths. No evidence for local tumor recurrence was identified in any patients with follow-up contrast-enhanced CT or MRI obtained 3 months or longer from the time of the ablation. Follow-up in these patients averaged 15 months (range 3-42 mos). CONCLUSION: Percutaneous cryoablation of renal masses >or=3 cm in diameter can be performed with high technical success and low complication rates. Extra scrutiny is needed during cryoablation of central renal masses to make sure the ablation zone extends to include the deepest margin of the tumor. Although our experience is limited, percutaneous cryoablation of renal tumors > 7 cm in diameter may be associated with increased complications. The lack of local renal tumor recurrences seen in this study on short-term follow-up is encouraging, but long-term follow-up remains necessary to ensure treatment durability.

Incidence of bleeding after 15,181 percutaneous biopsies and the role of aspirin.

OBJECTIVE: The objective of our study was to report the incidence of bleeding after imaging-guided percutaneous core biopsy at a single center using a standardized technique. MATERIALS AND METHODS: We performed a retrospective review of percutaneous core biopsies performed at our institution from January 2002 through February 2008. Data were collected at the time of biopsy, and clinical information was obtained 24 hours and 3 months after the biopsy. The specific information that was collected included the results of coagulation studies, aspirin use, the organ biopsied, the size of the biopsy needle, and the number of needle passes. Bleeding complications were defined using the Common Terminology Criteria for Adverse Events (CTCAE, version 3.0) established by the National Cancer Institute. RESULTS: Among the 15,181 percutaneous core biopsies performed during the study period, 70 hemorrhages (0.5%) that were CTCAE grade 3 or greater were identified within 3 months of biopsy. The incidence of bleeding in patients taking aspirin within 10 days before biopsy was 0.6% (18/3,195), which was not statistically different compared with the incidence of bleeding in those not taking aspirin (52/11,986, 0.4%; p = 0.34). The incidence of bleeding after liver biopsy was 0.5%; kidney biopsy, 0.7%; lung biopsy, 0.2%; pancreas biopsy, 1.0%; and other biopsy, 0.2%. There were significant associations between major bleeding and serum platelet count and international normalized ratio (p < 0.001), although the association between major bleeding and the size of the biopsy needle was not significant (p = 0.97). CONCLUSION: The overall incidence of major bleeding after imaging-guided percutaneous core needle biopsy is low. Recent aspirin therapy does not appear to significantly increase the risk of such bleeding complications.

Hydrodisplacement in the percutaneous cryoablation of 50 renal tumors.

OBJECTIVE: The purpose of this article is to describe the technique, safety, and effectiveness of percutaneous hydrodisplacement during the course of percutaneous renal cryoablation. MATERIALS AND METHODS: We retrospectively reviewed our experience in performing percutaneous hydrodisplacement during the cryoablation of renal tumors. In this subset of patients, we addressed tumor location within the kidney, tumor position relative to critical structures, effectiveness of hydrodisplacement, and complications in performing this adjunct technique. Comparisons between the two groups were made using Wilcoxon's rank sum test or chi-square test, as appropriate. RESULTS: Hydrodisplacement was attempted 52 times in 50 (24%) of 206 percutaneous renal tumor cryoablations. Tumors that were located anteriorly (p < 0.0001) or in the lower pole (p = 0.001) of the kidney were more likely to require hydrodisplacement. The colon required displacement most often (n = 41), followed by the body wall (n = 3), duodenum (n = 2), jejunum and ileum (n = 2), ureter (n = 1), and psoas muscle (n = 1). There was a single complication of hemorrhage resulting from injury to an intercostal artery branch that required termination of the procedure before fluid infusion. When fluid was infused, the critical structure was displaced in 50 (96%) of 52 attempts, displacing the critical structure from its initial location by a mean distance of 16 mm (range, 3-46 mm). Both failures occurred early in our experience with hydrodisplacement, and both required balloon displacement. CONCLUSION: Hydrodisplacement is a safe, effective, and commonly needed technique for displacement of critical structures before percutaneous cryoablation of renal tumors, particularly for tumors located anteriorly or in the lower pole of the kidney.

MRI after technically successful renal cryoablation: early contrast enhancement as a common finding.

OBJECTIVE: The purpose of this study was to assess the MRI appearance and enhancement of renal masses within 36 hours after cryoablation. MATERIALS AND METHODS: From March 2003 through January 2008, 129 patients underwent imaging-guided cryoablation for renal masses. Twenty-three of these patients underwent MRI within 36 hours after ablation. During MRI, acquisition of axial T1- and T2-weighted images was followed by administration of a gadolinium contrast agent. Standard follow-up included MRI 3-6 months after ablation. RESULTS: Eight of the 23 renal masses imaged within 6-36 hours after ablation were enhanced on MR images. Five of the eight lesions exhibited homogeneous enhancement, and the other three had heterogeneous or rim enhancement. Seven of the eight lesions exhibited no enhancement at the 6-month follow-up examination. One patient underwent follow-up imaging 10 months rather than 3-6 months after the procedure, but no enhancement was seen. T2-weighted signal intensity was mixed among the 23 renal masses. T1-weighted signal intensity was mixed among the 23 renal masses and the eight lesions that became enhanced, but there was a trend for higher T1 signal intensity at the 3- to 6-month follow-up examination. CONCLUSION: The high proportion of enhancing lesions 3 months after treatment and the resolution of enhancement 6 months afterward suggest that it may be reasonable to wait 6 months after technically successful renal cryoablation before performing contrast-enhanced MRI.

Thyroid follicular carcinoma: sonographic features of 50 cases.

OBJECTIVE: The purpose of our study was to retrospectively evaluate sonography of thyroid follicular neoplasms for features that would aid in distinguishing follicular carcinoma from follicular adenoma and for any imaging features that distinguish the Hürthle-cell variant of follicular carcinoma from classic follicular carcinoma. MATERIALS AND METHODS: The study cohort consisted of patients with the diagnosis of follicular carcinoma and patients with the diagnosis of follicular adenoma. Fifty patients (25 men and 25 women; median age, 59.5 years) with a diagnosis of follicular carcinoma (27 with classic follicular carcinoma, 22 with Hürthle-cell variant of follicular carcinoma, and one insular variant) in a 6-year period were included. Fifty-two control patients (10 men and 42 women; median age, 46.5 years) were selected from a random sampling of all cases of follicular adenoma during the same time period. Sonograms were reviewed in consensus by four radiologists for various features. All study patients and control patients underwent surgical resection and pathologic analysis of their thyroid follicular neoplasm. The chi-square or Fisher's exact test was used for categorical variables; the Wilcoxon's rank sum test was used for continuous variables. RESULTS: Hypoechoic appearance (82% of follicular carcinoma patients vs 50% of follicular adenoma patients; p<0.005; odds ratio [OR]), 0.5; 95% CI, 0.3-0.7), absence of halo (64% of follicular carcinoma patients vs 42% of follicular adenoma patients; p<0.05; OR, 0.4; 95% CI, 0.2-0.9), absence of cystic change (90% of follicular carcinoma patients vs 69% of follicular adenoma patients; p<0.05; OR, 0.2; 95% CI, 0.1-0.7), greater patient age (median age of 59.5 years for follicular carcinoma patients vs 46.5 years for follicular adenoma patients; p<0.05), size of the tumor (median size of 11.75 mL for follicular carcinoma patients vs 5.95 mL for follicular adenoma patients; p<0.05), and male sex (50% of follicular carcinoma patients vs 19.2% of follicular adenoma patients; p<0.005; OR, 3.7; 95% CI, 1.6-8.9) were more frequently associated with follicular thyroid cancer than with benign adenoma. No significant difference in the prevalence of refractive shadowing, echotexture, visible invasion, lymph node enlargement, adjacent nonfollicular suspicious lesions, vascularity subtype, and calcifications was observed between the two groups. Within the follicular carcinoma subgroup, homogeneous or predominantly homogeneous echotexture (67% of classic follicular carcinoma patients vs 36% of Hürthle-cell variant of follicular carcinoma patients; p<0.05; OR, 3.5; 95% CI, 1.1-11.4) and the presence of calcifications (22% of classic follicular carcinoma patients vs 4% of Hürthle-cell variant of follicular carcinoma patients [multivariate analysis including age]; p < 0.05; OR, 22.9; 95% CI, 2.0-261.9) were associated with classic follicular carcinoma. Greater patient age (median age of 53 years for classic follicular carcinoma patients vs 64.5 years for Hürthle-cell variant of follicular carcinoma patients; p<0.05) was associated with Hürthle-cell variant follicular carcinoma. There was no association between tumor volume, sex, sonographic halo, refractive shadowing, echogenicity, visible invasion, lymph node enlargement, adjacent nonfollicular suspicious lesions, vascularity subtype, and cystic change between the subgroups of follicular carcinoma. CONCLUSION: The sonographic features of follicular adenoma and follicular carcinoma are very similar, but larger lesion size, lack of a sonographic halo, hypoechoic appearance, and absence of cystic change favored a follicular carcinoma diagnosis. Increased patient age and male sex are associated with malignancy. Within the follicular carcinoma subgroup, Hürthle-cell variant of follicular carcinoma is more often seen in older patients with nodules having a heterogeneous appearance and lacking internal calcifications.