Characteristics and prognostic analysis of patients with detected KRAS mutations in resected lung adenocarcinomas by peptide nucleic acid-locked nucleic acid polymerase chain reaction (PNA-LNA PCR) clamp method.

Background: Kirsten rat sarcoma virus (KRAS) gene mutations are a type of driver mutation discovered in the 1980s, but for a long time no molecular targeted drugs were available for them. Recently, sotorasib was developed as a molecular targeted drug for KRAS mutations. It is therefore necessary to identify the characteristics of patients with KRAS mutations. Methods: This was the single-institution retrospective study. Surgically resected tumors from lung adenocarcinoma patients were collected at a single institution from June 2016 to September 2019. Peptide nucleic acid-locked nucleic acid polymerase chain reaction (PNA-LNA PCR) clamp analysis of KRAS G12X mutations was compared with analysis by therascreen KRAS RGQ kit. The association between KRAS mutation status and patient characteristics and prognosis was assessed. Results: Among 499 lung adenocarcinomas, KRAS mutations were evaluated in 197 cases, excluding stage IV lung cancer and tumors with epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) mutations. KRAS G12X mutations were detected in 59 cases (29.9%). The highest frequency by gene mutation subtype was G12V in 23 cases (39.0%), followed by G12C in 16 cases (27.1%), G12D in 12 cases (20.3%), G12S in 4 cases (6.8%) and G12A in 2 cases. For the G12C mutation, the PNA-LNA PCR clamp and therascreen methods were consistent, but for the G12D and G12S mutations, the PNA-LNA PCR clamp method showed higher detection rates. In operable tumors, G12C mutations were more frequent in males, smokers, and patients with high expression of programmed death-ligand 1 (PD-L1), and had no correlation with prognosis. Conclusions: By the PNA-LNA PCR clamp method, G12C mutation of surgical specimens was detected successfully. The PNA-LNA PCR clamp method is expected to be applied to the detection of druggable G12C mutations.

Monitoring of Plasma EGFR Mutations during Osimertinib Treatment for NSCLC Patients with Acquired T790M Mutation.

BACKGROUND: Osimertinib was first approved for the treatment of non-small cell lung cancer (NSCLC) in patients who have developed the epidermal growth factor receptor (EGFR) T790M mutation after treatment with EGFR tyrosine kinase inhibitors (TKIs). We routinely evaluated the plasma of NSCLC patients with the T790M mutation to more rapidly detect an increase in disease activity and resistance to treatment. METHODS: Eligible patients received osimertinib after resistance to the first- or second-generation of EGFR-TKIs in NSCLC harboring T790M mutation detectable in tumor tissue or plasma. Plasma samples were collected every 8 weeks during osimertinib treatment. The plasma analysis was performed using an improved PNA-LNA PCR clamp method. We tested samples for a resistance mechanism, including EGFR-activating, T790M, and C797S mutations, and assessed the association between the mutations and osimertinib treatment. RESULTS: Of the 60 patients enrolled in the study, 58 were eligible for this analysis. In plasma collected before osimertinib treatment, activating mutations were detected in 47 of 58 patients (81.0%) and T790M was detected in 44 patients (75.9%). Activating mutations were cleared in 60.9% (28/46) and T790M was cleared in 93.0% (40/43). Of these, 71.4% (20/28) of activating mutations and 87.5% (35/40) of T790M mutation were cleared within 8 weeks of treatment. The total response rate (RR) was 53.4% (31/58). The median duration of treatment was 259 days, with a trend toward longer treatment duration in patients who experienced the clearance of activating mutations with osimertinib. At the time of disease progression during osimertinib treatment, C797S was detected in 3 of 37 patients (8.1%). CONCLUSION: Plasma EGFR mutation analysis was effective in predicting the effect of osimertinib treatment.

Development of a Detection System for ESR1 Mutations in Circulating Tumour DNA Using PNA-LNA-Mediated PCR Clamping.

Although circulating tumour DNA (ctDNA)-based next-generation sequencing (NGS) is a less invasive method for assessing ESR1 mutations that are essential mechanisms of endocrine therapy resistance in patients with oestrogen receptor-positive breast cancer, adequate amounts of DNA are required to assess polyclonal ESR1 mutations. By combining a peptide nucleic acid and locked nucleic acid polymerase chain reaction (PNA-LNA PCR) clamping assay, we have developed a novel detection system to screen for polyclonal ESR1 mutations in ctDNA. A validation assay was prospectively performed on clinical samples and compared with the NGS results. The PNA-LNA PCR clamp assay was validated using six and four blood samples in which ESR1 mutations were detected by NGS and no mutations were detected, respectively. The PNA-LNA assay results were comparable with those of NGS. We prospectively assessed the concordance between the PNA-LNA PCR clamp method and NGS. Using the PNA-LNA PCR clamp method, ESR1 mutations were detected in 5 out of 18 samples, including those in which mutations were not detected by NGS due to small amounts of ctDNA. The PNA-LNA PCR clamping method is a highly sensitive and minimally invasive assay for polyclonal ESR1 mutation detection in the ctDNA of patients with breast cancer.

EGFR Mutation Analysis of Circulating Tumor DNA Using an Improved PNA-LNA PCR Clamp Method.

Introduction. Rebiopsies have become more crucial in non-small cell lung cancer (NSCLC). Instead of invasive biopsies, development of collecting biological data of the tumor from blood samples is expected. We conducted a prospective study to assess the feasibility of detection of epidermal growth factor receptor (EGFR) mutation in plasma samples. Method. NSCLC patients harboring EGFR activating mutations, who were going to receive EGFR-tyrosine kinase inhibitors (TKIs) as first-line treatment, were enrolled in this study. Plasma EGFR activating mutations and the T790M resistance mutation were analyzed by an improved PNA-LNA PCR clamp method, characterized by a 10-fold or more sensitivity compared with the original methods. Result. Six patients with wild-type EGFR and 24 patients with EGFR mutations were enrolled in this study. Pretreatment plasma samples achieved sensitivity of 79%. The 6 patients with wild-type EGFR were all negative for plasma EGFR mutations. At the time of disease progression, plasma T790M mutation was detected in 8 of 16 cases. Absence of T790M before and during TKI treatment and disappearance of activating mutations during TKI treatment were considered as predictors of EGFR-TKIs efficacy. Conclusion. We were able to detect EGFR mutations in plasma samples by using an improved PNA-LNA PCR clamp method.

Hydrocele of the canal of Nuck: a case report with magnetic resonance hydrography findings.

Hydrocele of the canal of Nuck, also called the "female hydrocele," is a rare developmental disorder in females. This entity is now believed to be more common now in comparison with previous reports; however, it is still an unfamiliar problem for physicians. The processus vaginalis accompanies the round ligament through the inguinal canal into the labium majus. This evagination of the parietal peritoneum forms the canal of Nuck in the female. The canal of Nuck normally loses its connection with the peritoneal cavity during the first year of life, but can result in a hernia or hydrocele when the connection of the canal of Nuck fails to close. Here, we present the case of a 43-year-old female who complained of swelling in the right inguinal region. Coronal and axial magnetic resonance imaging (MRI) revealed a cystic mass lesion with an irregular shape in the right inguinal region, and smaller cystic lesions extending alongside the right round ligament were also identified in the right side of the pelvic cavity. Magnetic resonance (MR) hydrography revealed the uninterrupted cystic lesion from the inguinal region to the pelvic cavity, with constrictions at the internal and external inguinal rings. These MR findings proved to be incredibly useful for surgical planning.

Assessment of MR Imaging as a Tool to Differentiate between the Major Histological Types of Uterine Sarcomas.

OBJECTIVES: We retrospectively compared and quantified magnetic resonance (MR) images to distinguish major histological types of uterine sarcomas and malignant and benign tumors. METHODS: MR images were obtained from patients who underwent preoperative examinations. We compared 25 pathologically confirmed uterine sarcomas (8 leiomyosarcomas, 11 carcinosarcomas, 6 endometrial stromal sarcomas) with 25 uterine leiomyomas. MR findings included tumor size, location, contour, signal intensity (SI), and contrast enhancement. Analysis focused on the contrast ratio (CR) of SI in T2-weighted images for the areas of lowest, highest, and main SI of each tumor as well as the contrast-enhanced ratio (CER) for the main solid part of each tumor in contrast-enhanced T1-weighted images. We evaluated diffusion-weighted (DW) images and apparent diffusion coefficient (ADC) values in 18 tumors (4 sarcomas, 14 leiomyomas). RESULTS: Uterine sarcomas and leiomyomas differed significantly in tumor location, contour, hemorrhaging, necrotic and cystic components, CR for the area of lowest SI (P < 0.05), CR for the area of main SI (P < 0.01), and CER (P < 0.05). Leiomyosarcomas were larger than carcinosarcomas or endometrial stromal sarcomas, and the CR for the area of lowest SI of leiomyosarcomas (P < 0.05) was significantly lower. The CER for endometrial stromal sarcomas (P < 0.05) showed the most homogeneous enhancement. Hemorrhagic or necrotic and cystic components were found more often in larger tumors, although there was no significant difference in their occurrence between sarcoma types. All uterine sarcomas showed high intensity on DW images. The ADC values were lower of uterine sarcomas than leiomyomas, although the difference was not statistically significant. CONCLUSION: Quantitative assessment using the CR or CER was useful for distinguishing benign and malignant uterine tumors as well as major histological types of uterine sarcomas.

Management of breast papillary lesions diagnosed in ultrasound-guided vacuum-assisted and core needle biopsies.

AIMS: To assess the outcome of breast papillary lesions diagnosed by ultrasound-guided core needle biopsy (CB) or vacuum-assisted 'mammotome' biopsy (MT), the accuracy of these diagnoses, and whether it is justified not to undertake surgical excision of non-malignant papillary lesions so diagnosed. METHODS AND RESULTS: Among 3219 (MT, 2195; CB, 1024) breast biopsies spanning 5 years, 185 (5.7%) papillary lesions [MT, 162 (88%); CB, 23 (12%)] were identified. Of these, 142 cases (77%; MT/CB, 125/17) were benign, 24 (13%, 23/1) were atypical, and 19 (10%; 14/5) were malignant. Of the 142 benign cases, 114 had imaging follow-up (FU) (FU period 2-81 months); 17 of 114 cases were excised, and four were malignant (3.5%) (FU period 4-57 months). Of the 24 atypical cases (23 had FU), 19 were excised: six were benign (32%) and 13 malignant (68%). The remaining four cases were considered to be non-malignant (FU period 7-54 months). CONCLUSIONS: Benign papillary lesions diagnosed by MT or CB might not require immediate excision, but should receive imaging FU for at least 5 years. Excision should be performed in cases showing changes in imaging features, as the possibilities of carcinoma coexisting with papilloma or carcinoma developing from papilloma cannot be excluded, as illustrated by the 4% upgrade rate at excision in this study.

Broad fibrovascular cores may not be an exclusively benign feature in papillary lesions of the breast: a cautionary note.

AIMS: A prominent fibrovascular stromal core is one of the widely accepted histological features of breast papillomas, but some papillary carcinomas also show such broad fibrovascular cores, leading to confusion in diagnosis, particularly in needle biopsy specimens. We investigated the histological characteristics of papillary lesions, focusing on broad fibrovascular cores and their relationship with the architectural patterns. METHODS: Among 185 cases of needle biopsies of papillomas and papillary carcinomas, the number of cases with broad fibrovascular cores in each group was compared. The broad fibrovascular core density in the subsequently resected specimens was evaluated and compared between papillary predominant pattern (papillary structures >80% of tumours) and mixed pattern (papillary, solid, cribriform and others) within the lesions. RESULTS: Significantly more papillary carcinomas than papillomas and B3 atypical papillary lesions had broad fibrovascular cores (p=0.0091 and p=0.0164, respectively). The papillary predominant pattern was more prominent in carcinomas than in papillomas in the needle biopsies (p=0.048) and showed the same tendency in the resections (p=0.058). The broad fibrovascular core density was significantly lower in the 18 papillomas than in the 37 papillary carcinomas (p=0.0079) and was not significantly different between the papillary predominant and mixed patterns in carcinomas and papillomas. CONCLUSIONS: Broad fibrovascular cores in mammary papillary lesions are not specific for papillomas, as they are also present focally in papillary carcinomas. As the frequency of papillary carcinoma with broad fibrovascular cores is relatively high, caution in diagnosis has to be exercised, especially in needle biopsy specimens.

Pure flat epithelial atypia is uncommon in subsequent breast excisions for atypical epithelial proliferation.

The management of atypical intraductal lesions of the breast remains controversial. In the present study, the subsequent surgical excision results and follow-up data on 86 (3.65%) atypical intraductal lesions and 78 (3.31%) low-grade ductal carcinoma in situ (DCIS) from a cohort of 2358 needle biopsies were examined. There were 17 cases (0.72%) of pure flat epithelial atypia (FEA), 44 (1.87%) pure atypical ductal hyperplasia (ADH), three (0.13%) pure atypical lobular hyperplasia (ALH), 18 (0.76%) combined ADH + FEA, three (0.13%) combined ALH + FEA and one (0.04%) combined ALH + FEA + ADH. Subsequent surgical excisions were done in 53 cases and revealed the following incidences of malignancy: pure FEA (1/8); pure ADH (17/31); FEA + ADH (7/10); FEA + ALH (2/3); and FEA + ALH + ADH (0/1), with pure FEA showing significantly lower incidence of malignancy. In this cohort, there were 703 carcinomas including 155 DCIS with 78 cases (50.3%) being low-grade. FEA with ADH (and/or ALH) was present in 22 (28.2%) of these 78 cases of low-grade DCISs at surgical excisions. Pure FEA was not detected in any of the subsequently excised surgical materials of the atypical intraductal lesions nor the low-grade DCISs. Thus, pure FEA was very unusual in surgical specimens. When pure FEA is detected at needle biopsy, a wait and see approach can be adopted. However, when the FEA is associated with other concomitant atypical intraductal lesions, especially ADH, further excision should be contemplated.

"High-grade" central acellular carcinoma and matrix-producing carcinoma of the breast: correlation between ultrasonographic findings and pathological features.

High-grade carcinoma with a large central acellular zone (central acellular carcinoma, CAC) and matrixproducing carcinoma (MPC) are aggressive tumors that both have a central myxomatous acellular zone. Their characteristic morphology may be useful in diagnostic imaging. Ultrasonographic findings based on the Breast Imaging Recording and Data System (BI-RADS) and detailed histological features were evaluated in 11 cases of CAC and 2 cases of MPC to characterize their features. Safranin-O staining was undertaken for the evaluation of central acellular zones in these tumors. Overall, ultrasonography demonstrated heterogeneous hyperechoic lesions in the center of the hypoechoic mass. Posterior echo enhancement was observed in all but 1 case. One case was classified as malignant and the others as "borderline." Histologically, cancer tissue was located in the periphery of the tumor with a ring-like structure and fewer cellular central areas comprising hyaline cartilage myxoid material such as those stained by safranin-O. The present study showed that the pathological findings of CACs and MPCs accurately reflect the ultrasonographic findings. Tumors that showed hyperechoic areas in the center of the hypoechoic mass, with posterior echo enhancement indicating acellular zones composed by myxochondroid material, and that were also relatively round on ultrasonography may be benign, but evaluation is required to exclude CAC and MPC.

Myxomatous fibroadenoma of the breast: correlation with clinicopathologic and radiologic features.

Fibroadenoma is a frequently encountered benign tumor that must be differentiated from carcinoma. Fibroadenomas often exhibit myxedematous changes (myxomatous fibroadenoma). We focused on myxomatous fibroadenomas and evaluated their diagnostic imaging and clinicopathologic findings. We examined the (1) clinicopathologic findings of myxomatous fibroadenomas out of 113 fibroadenomas among 592 needle biopsy cases and (2) clinical findings of 27 patients with fibroadenoma who underwent surgical resection. One hundred thirteen (19%) of 592 cases were fibroadenoma, of which 45 cases (40%) were myxomatous fibroadenoma. Based on ultrasonography findings, the depth to width ratio was significantly higher in the myxomatous fibroadenoma group (0.79 ± 0.26) compared with the non-myxomatous fibroadenoma group (0.64 ± 0.26) (P < .01). Forty-two patients were subjected to needle biopsy to differentiate fibroadenoma from carcinomas based on ultrasonography and clinical findings, of which 13 cases (31%) were myxomatous fibroadenoma. These lesions showed a relatively round shape and increased posterior echo enhancement with internal hyperechogenicity on ultrasonography. Among 17 resected cases suspected of malignancy that showed rapid growth and/or size greater than 3 cm, 16 cases were myxomatous fibroadenoma. Tumors showing rapid growth and a relatively large size, a high depth to width ratio, a relatively round shape, and posterior echo enhancement with internal hyperechogenicity on ultrasonography require differentiation from (mucinous) carcinoma but are histologically more likely to be myxomatous fibroadenoma. Understanding the histologic features and combining the ultrasonography findings of myxomatous fibroadenomas may permit reduction in the number of unnecessary needle biopsies for tumor-forming lesions.

Lung adenocarcinoma, mixed subtype: histopathologic basis for high-resolution computed tomography findings.

"Adenocarcinoma, mixed subtype" is the most common histologic subtype of lung adenocarcinomas in the World Health Organization classification of 2004. For small peripheral adenocarcinomas, for example, those measuring 2 cm or less in greatest diameter, invasive areas can present various histologic patterns. The purpose of this study is to present the radiologic features of small peripheral lung adenocarcinomas with or without a bronchioloalveolar component and with or without invasive areas, in comparison with histopathologic findings. For this purpose, a detailed evaluation of the characteristics of solid regions in ground-glass opacity on high-resolution computerized tomographic images of lung adenocarcinoma is useful.

Quality control and monitoring for the isolation process of mesenchymal stem cells and their differentiation into osteoblasts.

We developed a method of quality control and monitoring for the isolation of mesenchymal stem cells (MSCs) from bone marrow and their differentiation into osteoblasts. After dividing the cell culture process into five groups based on cell types such as MSCs and osteoblasts, we used microarray analysis to select genes with expression profiles characteristic of each group and quantitative polymerase chain reaction for confirming the expression profiles of these genes. Comparing multiple gene expression profiles per cell from quantitative polymerase chain reaction permitted us to distinguish (1) different groups of cell culture including MSCs and osteoblasts; (2) MSCs that had differentiated cells other than osteoblasts such as chondroblasts, adipocytes, or skin-derived fibroblasts; and (3) desirable MSCs from undesirable MSCs occurring under different culture conditions. These findings suggest that it is possible to standardize MSCs and osteoblasts on the basis of multiple gene expression profiles and to check the quality of these cells. We believe that our methods can be applied to cells cultured for transplants.

Pleomorphic carcinoma of the breast in a 17-year-old woman.

We report a 17-year-old woman with refractory high-grade breast cancer who died early after surgery, with reference to the histogenesis of the cancer. Macroscopically, the tumor was cystic, composed of a mixture of solid and myxomatous areas. Histologically, the tumor exhibited ductal structures and areas with squamoid features. Cancer cells were markedly atypical and polymorphic, and included a mixture of bizarre and eosinophilic cells with rhabdoid feature-like free cells. Immunohistochemically, cytokeratin (CK) 8, CK 18, 34 beta E12, CD10, involucrin, CK14, and vimentin were partially positive, whereas estrogen and progesterone receptors and HER-2 were negative. These findings suggest an undifferentiated cancer whose cells have multilineage potential to differentiate into mesenchymal, basal, and squamoid cells, and it was diagnosed as pleomorphic carcinoma, which is a histological type hitherto unreported in young girls. The cancer was refractory to treatment, and the patient died 1 year and 5 months after surgery despite chemotherapy and radiotherapy.

Clinicocytopathology of breast cancers with a ring-like appearance on ultrasonography and/or magnetic resonance imaging.

On breast cancer imaging some cancers have an anechoic or high-echoic zone in the tumor on ultrasonography and ring-shaped enhancement on contrast-enhanced magnetic resonance imaging (MRI) with high intensity in the central area of the tumor on T2-weighted imaging, necessitating their differentiation from benign disease. Thus, nine breast cancers with a ring-like appearance on imaging were analyzed on cytopathology. Histologically the cancer cells of these lesions showing a ring-like appearance were located in the periphery of the tumor, with a central hypocellular zone. Five such lesions with a thick, doughnut-like appearance were identified as cancers with acellular zones (CAC), and four lesions with a thinner, rim-like appearance as matrix-producing carcinomas (MPC). The percentage ratio of the cancer-zone width to the tumor diameter was 26.4 +/- 7.8 and 8.0 +/- 3.2 (mean +/- SD), respectively (P= 0.003). Cytologically, highly atypical, naked-nucleus cells were observed in eight of the nine cancers. In two MPC and three CAC, cartilage matrix and amorphous material, respectively, were observed in the background. In summary, the present series of breast cancers having a ring appearance on imaging did not have uniform cytopathological features. They were classified as MPC or CAC, and cytology was useful in their diagnosis and differentiation in some cases.

Neuroendocrine small cell carcinoma of the breast: report of a case.

A rare case of neuroendocrine small cell carcinoma (SmCC) of the breast is reported. A 51-year-old postmenopausal woman noticed a nodule approximately 3 cm in diameter in her right upper breast. Histologically, the tumor consisted of small ovoid to pleomorphic cells with hyperchromatic nuclei, and a large central area was occupied by acellular amorphous tissue. Extensive lymphatic permeation was seen around the tumor. Invasive and in situ ductal carcinoma foci were not observed in and surrounding the tumor. Immunohistochemically, estrogen and progesterone receptors and HER2/neu were all negative in the tumor cells. Synaptophysin and chromogranin A were diffusely positive in the tumor cells. Cytokeratin 8 was only positive in a few tumor cells. The labeling indices of Ki-67 and p53 were high in the tumor. Postoperatively, systemic studies including positron emission tomography were performed but failed to reveal any other possible primary sites, including lung. Based on these findings, the tumor was diagnosed as neuroendocrine primary SmCC of the breast. Postoperatively, the patient received a course of weekly paclitaxel. However, pelvic bone metastasis was identified on a bone scintigram 1 year after surgery. Mammary SmCC showing high Ki-67 and p53 index should be treated carefully because of their aggressive clinical behavior.

Frequent and variable abnormalities in p14 tumor suppressor gene in glioma cell lines.

Ten glioma cell lines were examined for abnormalities of exon 1beta of the p14 gene and then for abnormalities of the entire p14 gene with the use of previous findings of other exons. Abnormalities of exon 1beta and the entire p14 gene were detected in eight of ten cases: homozygous deletion of the entire gene in six cases, hemizygous deletion of exon 1beta with homozygous deletion of downstream exons in one case, and hemizygous deletion of the entire coding region with a missense mutation (A97V) at the C-terminal nucleolar localization domain in one case. The remaining two cases revealed no such abnormalities. p14 gene expression was observed in the latter two cases and one case with A97V mutation in the hemizygously deleted coding region, but not in the others, including one case with only exon 1beta. In the three cases with p14 gene expression, immunocytochemistry revealed p14 nucleolar staining, suggesting the retention of the functional activity of p14 protein and, in the case with the A97V mutation, an insufficient mutational effect as well. The present findings of the frequent and variable p14 gene abnormalities, including rare-type ones with or without sufficient mutational effect in glioma cell lines, might be of value for better understanding of the p14 gene and its related pathways in glioma carcinogenesis.

Dynamic MRI of solitary pulmonary nodules: comparison of enhancement patterns of malignant and benign small peripheral lung lesions.

OBJECTIVE: The purpose of this study was to compare the dynamic contrast-enhanced MRI enhancement characteristics of malignant and benign solitary pulmonary nodules. MATERIALS AND METHODS: The characteristics of 202 solitary pulmonary nodules (diameter, 1-3 cm; 144 cases of primary lung cancer, 31 cases of focal organizing pneumonia, 15 tuberculomas, 12 hamartomas) were reviewed retrospectively. In all cases dynamic MR images were obtained before and 1, 2, 3, 4, 5, 6, and 8 minutes after bolus injection of gadopentetate dimeglumine. Maximum enhancement ratio, time at maximum enhancement ratio, slope of time-enhancement ratio curves, and washout ratio were assessed. Statistical analyses were performed with the Kruskal-Wallis test with Bonferroni correction, chi-square test, and receiver operating characteristic curves. RESULTS: For 122 (85%) of 144 primary lung cancers, time at maximum enhancement ratio was 4 minutes or less. For all tuberculomas and hamartomas, time at maximum enhancement ratio was greater than 4 minutes or gradual enhancement occurred without a peak time (p < 0.0001). Lung cancers had different maximum enhancement ratios and slopes than benign lesions (all p < 0.005). With 110% or lower maximum enhancement ratio as a cutoff value, the positive predictive value for malignancy was 92%; sensitivity, 63%; and specificity, 74%. With 13.5%/min or greater slope as a cutoff value, sensitivity, specificity, positive predictive value, and negative predictive value for malignancy were 94%, 96%, 99%, and 74%, respectively. CONCLUSION: Dynamic contrast-enhanced MRI is helpful in differentiating benign from malignant solitary pulmonary nodules. Absence of significant enhancement is a strong predictor that a lesion is benign.

Venous hemangioma arising from the diaphragm: a case report of computed tomography and magnetic resonance imaging findings.

We report a rare case of diaphragmatic hemangioma with computed tomography and magnetic resonance imaging findings. A routine chest radiograph in a 75-year-old woman revealed a nodular opacity in the right lower lung field. Multidetector-row computed tomography revealed a well-circumscribed nodule arising from the diaphragm or pleura. Dynamic magnetic resonance imaging of the nodule showed a pattern of gradually increasing signal intensity. On the basis of the intraoperative and histopathologic findings, venous hemangioma arising from the diaphragm was diagnosed.