[en] We wanted to investigate the ability of breast MR imaging to identify the primary malignancy in patients with axillary lymph node metastases and initially negative mammography and sonography, and we correlated those results with the conventional imaging. From September 2001 to April 2006, 12 patients with axillary lymph node metastases and initially negative mammography and sonography underwent breast MR imaging to identify occult breast carcinoma. We analyzed the findings of the MR imaging, the MR-correlated mammography and the second-look sonography. We followed up both the MR-positive and MR-negative patients. MR imaging detected occult breast carcinoma in 10 of 12 (83%) patients. Two MR-negative patients were free of carcinoma in the ipsilateral breast during their follow-up period (39 and 44 months, respectively). In nine out of 10 patients, the MR-correlated mammography and second-look sonography localized lesions that were not detected on the initial exam. All the non-MR-correlated sonographic abnormalities were benign. Breast MR imaging can identify otherwise occult breast cancer in patients with metastatic axillary lymph nodes. Localization of the lesions through MR-correlated mammography and second-look sonography is practically feasible in most cases

[en] To evaluate the usefulness of multidetector-row computed tomography (CT) in the evaluation of myocardial infarction. Eleven rabbits were subjected to 90-min occlusion of the left anterior descending coronary artery followed by reperfusion. Multidetector-row CT was performed 31 hours ± 21 after the procedure and pre- and post-contrast multiphase helical CT images were obtained up to 10 min after contrast injection. The animals were sacrificed after 30 days and histochemical staining of the resected specimens was perfomed with 2'3'5-triphenyl tetrazolium chloride (TTC). In all 11 cases, the areas of myocardial infarction demonstrated with TTC-staining were identified on the CT images and the lesions showed hypoen- hancement on the early phases up to 62 sec and hyperenhancement on the delayed phases of 5 min and 10 min compared with normal myocardial enhancement. The percentage area of the lesion with respect to the left ventricle wall on CT was significantly correlated with that of the TTC-staining results (ρ<0.001 for both early and delayed phase CT) according to the generalized linear model analysis. The areas showing hypoenhancement on early CT were significantly smaller than those with hyperenhancement on delayed CT (ρ<0.0001). Multiedtector-row CT may be useful in the detection and sizing of reperfused myocardial infarction

[en] We wanted to evaluate the sonographic findings of recurrent breast cancer in the patients who underwent mastectomy or breast conserving surgery (BCS). We also wanted to evaluate the characteristics of recurrent cancer that's detected on follow up sonography only. We retrospectively reviewed 87 patients with recurrent breast cancer and who were operated on during the previous 10 years. We analyzed the method of detection and the sonographic appearance of tumor, including the location, size, shape, margin, internal echogenicity and BI-RADS categories, in 52 patients who had abnormal sonographic findings. We compared the sonographic findings of the recurrent cancer between the patients who underwent mastectomy and the patients who underwent BCS. We also analyzed the characters of the recurrent cancer that was only detectable on follow-up sonography. Among the 87 patients with recurrent breast cancer, 37 patients had undergone previous mastectomy and 50 patients had undergone previous BCS. The most common mode of detection was a palpable mass on physical examination for the patients who underwent mastectomy (64.9%, 24/37) and the most common mode of detection was the follow-up sonography for the patients who underwent BCS (40%, 20/50). The sonographic appearance of the recurrent cancer was similar for both the patients who underwent mastectomy or BCS. The most common locations were the breast parenchymal layer in 82% (36/44) of the patients who underwent BCS and the subcutaneous fat layer of the operated area in 67% (14/21) of the patients who underwent mastectomy. The type of recurrent cancer detected on sonography only was small nodules in the patients who underwent BCS, and that for the patients who underwent mastectomy was nodules, regardless of size, that were located in the deep muscle layer. Recurrent breast cancer, regardless of size, was frequently detected on a physical examination in the patients who underwent previous mastectomy, and this was detected on sonography in the patients who underwent with previous BCS. Follow up sonography was valuable to evaluate for tumor recurrence after breast cancer surgery, and this detected 16% (6/37), 28% (14/50) of the recurrent cancers that were otherwise occult tumor

[en] To review the retrospective imaging findings of thyroid cancer initially assessed as no suspicious malignancy. Of 338 nodules confirmed to be thyroid cancer, this study included 38 patients with 39 nodules assessed as no suspicious malignancy on initial sonography. (mean age:39 years, 36 females and 2 males). We evaluated sonographic findings by shape, margin, echogenecity, calcification, cystic degeneration and peripheral hypoechoic rim retrospectively. We analyzed whether sonographic findings were different according to the size (standard:1 cm). The most frequent sonographic findings were avoid to round shape 90%, well-defined smooth margin 64%, hypoechogenecity 54%, no calcification 92%, no cystic degeneration 77% and peripheral hypoechoic rim 56%. Suspicious malignancy findings were taller than wide shape 10%, well-defined spiculated margin 36%, markedly hypoechogenecity 10% and microcalcifications 8%. Isoechogenecity, cystic degeneration and peripheral hypoechoic rim were common in 1 cm more than nodules. Well-defined spiculated margin was common in 1 cm less than nodules. In retrospective, 56% showed no suspicious malignancy finding. Although nodules assessed as no suspicious malignancy on initial US had many retrospectively suspicious malignancy findings, still many nodules showed no suspicious malignancy finding. Suspicious findings were ignored due to equivocal finding in small size, isoechogenecity, cystic degeneration or peripheral hypoechoic rim. We need careful observation

[en] The aim of our study was to evaluate the outcomes of sonographic (US) BIRADS category 4 lesions according to subcategories 4A, 4B, and 4C and palpability. We retrospectively reviewed the pathology results of 512 US BI-RADS category 4 lesions in 460 patients after ultrasound-guided percutaneous biopsy (n = 435) and surgical biopsy (n = 77). We analyzed the results according to subcategories 4A, 4B, 4C, and palpability, and compared outcomes of five breast radiologists. In BI-RADS 4A lesions (n = 302), biopsy results indicated 48 malignancies(15.9%). In BI-RADS 4B lesions (n = 113), biopsy revealed 69 malignancies (61.1%). Among BI-RADS 4C lesions (n = 97), 87 lesions were malignancies (89.7 %). Palpability had no correlation with the rate of malignancy in BI-RADS category 4 lesions, and the rate of malignancy for category 4A ranged widely from 8.1% - 26.4%. The outcomes of US BI-RADS category 4 lesions according to subcategories varied widely between radiologists, especially for 4A lesions. The US finding itself warrants a BI-RADS 4 subcategory. In category 4 lesions, the malignant rate was the same between palpable and nonpalpable lesions

[en] To evaluate the sonographic and mammographic features of apocrine metaplasia of the breast. We retrospectively evaluated the sonographic and mammographic findings of 16 lesions that were diagnosed with only apocrine metaplasia after mammotome excision. The age ranged from 27 years old to 57 years old (mean age: 40 years old). The sonographic features were interpreted by the ACR BI-RADS(American College of Radiology Breast Imaging Reporting and Data System) for shape, orientation, margin, boundary, echo pattern, posterior acoustic feature, calcification and special cases. The mammographic features were interpreted by the ACR BI-RADS (American College of Radiology Breast Imaging Reporting and Data System) for breast composition, shape, margin, density and calcification. Sonographic features were that the shapes were oval (n = 16) in 100%. The orientation was parallel (n =15) in 94%. The margins were circumscribed (n = 8) in 50% and microlobulated (n = 8) in 50%. The echo patterns were hypoechoic (n = 8) in 50%, complex (n = 5) in 31% and anechoic (n = 3) in 19%. Posterior acoustic enhancement was seen in 69% (n = 11). There was internal microcyst (n = 4) in 25%. There was no calcification. Mammography performed for 12 cases demonstrated negative findings (n = 10) for 83%, obscured hypodense mass (n = 1) for 8% in 11 cases of breast composition 3 and 4, and circumscribed isodense mass (n = 1)for 8% in one case of breast composition 2. There was no calcification. The final assessment was category 4a (n= 7) in 44%, category 3 (n = 6) in 38% and category 2 (n = 3) in 19%. Although sonographic and mammographic features of apocrine metaplasia are occasionally suspicious malignancy such as microlobulation and complex echo. We consider the possibility of apocrine metaplasia if masses show internal microcyst and abrupt boundary

[en] Metastases from thymoma usually occur within the thorax and only 3% of patients have extrathoracic lesions. One study reported that the mean interval between detecting primary tumor and detecting extrathoracic metastasis was nine years, and the maximum interval was 21 years. This suggests that thymic tumor can metastasize even a long time after treatment of the initial mediastinal mass, along with it growing very slowly. Therefore, when the patient with a breast mass has a history of thymic tumor, metastasis from thymic tumor should be included in a differential diagnosis regardless of the initial low malignant potential of thymic tumor or the long disease free period. Breast metastasis from nonmammary malignant neoplasms is uncommon, and it accounts for approximately 2% of all breast tumors. Distant metastasis of thymoma is very rare, and especially to extrathorcic areas. We report a female who had a metastatic thymoma in her breast 20 years after undergoing resection for a non-invasive thymoma. She presented with a palpable mass in her left breast. Mammography and ultrasonogram showed a lobular mass at the anterior glandular portion. Histological examination after surgical excision revealed a metastatic thymoma

[en] Apocrine carcinoma is a rare breast cancer and its frequency is about 0.4% of all breast cancers. Little is known about its clinical behavior and prognosis. To our knowledge, few studies have reported the radiologic appearances of apocrine carcinoma in the breast and there has been no such report from Korea. We describe the sonographic findings of a case of apocrine carcinoma in the breast. The sonographic findings are microlobulated heterogeneous hypoechoic lesion that has a central markedly hypoechoic portion and a peripheral mixture of iso and hypoechgenecity

[en] We aimed to evaluate a possible role for BRAFV600E mutation analysis of aspiration specimens in the work up of thyroid nodules classified as indeterminate on US. A total of 122 nodules from 122 patients were prospectively classified as indeterminate nodules based on US findings. US-guided fine needle aspiration (FNA) was done for all 122 nodules. The presence of a BRAFV600E mutation in FNA specimens was determined by allele-specific PCR. US-indeterminate nodules were confirmed as malignant in 20.5% (25/122) of cases and benign in 76.2% (93/122) after FNA or surgery. A few (3.3% (4/122), remained indeterminate. A BRAFV600E mutation was identified in 14.8% (18/122) of US indeterminate nodules. Of those 18 nodules, three were benign and 13 were malignant after the initial FNA. One (0.8%, 1/122) with an initially benign cytology and a BRAFV600E mutation was confirmed to be malignant after surgery. The remaining two benign nodules with a mutation were not followed-up. All 9 initial FNA-nondiagnostic nodules were mutation negative but 2 (11.8%) of 17 indeterminate nodules on initial FNAs were mutation positive. BRAFV600E mutation analysis prevents false negative cytology for only 0.8% of cases and reduces ambiguous diagnoses for 1.6% of all US-indeterminate thyroid nodules. Therefore, adding BRAFV600E mutation analysis to FNA for US-indeterminate nodules is of limited usefulness

[en] Purpose: To retrospectively evaluate previous imaging findings of breast cancers that occurred in women whose combined screening using both mammography and ultrasonography was negative. Materials and methods: A search of the institutional database identified 65 patients with breast cancers who had comparable previous negative screening mammography and ultrasonography (BI-RADS category 1 or 2) within 2 years. We classified each case as true or false negative. The previous imaging findings and the final outcome were analyzed. Results: Among 65 cases, 42 (65%) were true negatives, 23 (35%) were false negatives. The abnormalities of false negatives were underestimated in 16 (70%) and unrecognized in 7 (30%). The findings were calcifications (n = 8) or a mass (n = 6) on mammography, a mass (n = 5) or a non-mass (n = 3) on ultrasonography and a density on mammography correlated with non-mass on ultrasonography (n = 1). Ductal carcinoma in situ among false and true negatives accounted for 5 (22%) and 7 (17%), respectively. Symptomatic cancers among false and true negatives were 6 (26%) and 13 (31%), respectively. Conclusion: Breast cancers that rarely occurred in combined screening negatives are often retrospectively seen as minimal abnormalities on previous imaging studies.