The role of MRS in the differentiation of benign and malignant soft tissue and bone tumors

Objective

The aim of our study was to investigate the value of choline in the discrimination of benign and malignant soft tissue and bone tumors.

Materials and methods

The study group consisted of thirty subjects with bone or soft tissue tumors larger than 1.5 cm in diameter. The experiments were performed in a 1.5 T MR scanner. Coils were selected according to specific locations. A single-voxel MRS was performed for three different TE (time to echo) (31, 136, 272 ms). The volume of interest was positioned on the brightest enhancement. The presence of a cholin peak on at least 2 of these spectrums was considered as the marker of malignancy. The sensitivity, specificity and accuracy of the MRS in the detection and diagnosis of malignant lesions were calculated. The reproducibility of MRS and histopathological results were tested with kappa statistics.

Results

Histopathologically, 18 (60%) of the lesions were classed as malignant whereas 12 (40%) were classed as benign. With MRS, 15 (50%) of these lesions were classed as malignant and 15 (50%) as benign. Two patients who were found spectroscopically to have malignant tumors were shown histopathologically to have benign types. Five patients with an MRS showing a benign type were classed with malignant types in histopathological examinations. MRS had a sensitivity rate of 72.2%, specificity of 83.3%, and an accuracy rate of 76.6% in detecting malignant bone and soft tissue tumors. The interrater reliability of both techniques had a kappa value of 0.533.

Conclusions

MRS may help in the differentiation of benign and malignant soft tissue and bone tumors.     

Dynamic susceptibility contrast perfusion MR imaging in distinguishing malignant from benign head and neck tumors: A pilot study

Purpose

To preliminarily investigate the utility of dynamic susceptibility contrast perfusion MR imaging in distinguishing malignant from benign head and neck tumors.

Material and methods

Seventy eight patients with head and neck masses underwent single shot dynamic susceptibility contrast T2*-weighted perfusion weighted MR imaging after bolus infusion of gadolinium-DTPA was administrated. The signal intensity time curve of the lesion was created. Dynamic susceptibility contrast percentage (DSC%) was calculated and correlated with pathological findings.

Results

The mean DSC% of malignant tumor (n = 40) was 39.3 ± 9.6% and of benign lesions (n = 38) was 24.3 ± 10.3%. There was a statistically significant difference of the DSC% between benign and malignant tumors (P = 0.001) and within benign tumors (P = 0.001). When DSC% of 30.7% was used as a threshold for differentiating malignant from benign tumors, the best results were obtained: accuracy of 84.6%, sensitivity of 80% and specificity of 89.2%.

Conclusion

Dynamic susceptibility contrast perfusion weighted MR imaging is a non-invasive imaging technique that can play a role in differentiation between malignant and benign head and neck tumors.     

Computer-aided diagnosis with textural features for breast lesions in sonograms

Rationale and objectives

Computer-aided diagnosis (CAD) systems provided second beneficial support reference and enhance the diagnostic accuracy. This paper was aimed to develop and evaluate a CAD with texture analysis in the classification of breast tumors for ultrasound images.

Materials and methods

The ultrasound (US) dataset evaluated in this study composed of 1020 sonograms of region of interest (ROI) subimages from 255 patients. Two-view sonogram (longitudinal and transverse views) and four different rectangular regions were utilized to analyze each tumor. Six practical textural features from the US images were performed to classify breast tumors as benign or malignant. However, the textural features always perform as a high dimensional vector; high dimensional vector is unfavorable to differentiate breast tumors in practice. The principal component analysis (PCA) was used to reduce the dimension of textural feature vector and then the image retrieval technique was performed to differentiate between benign and malignant tumors. In the experiments, all the cases were sampled with k-fold cross-validation (k = 10) to evaluate the performance with receiver operating characteristic (ROC) curve.

Results

The area (A_Z) under the ROC curve for the proposed CAD system with the specific textural features was 0.925 ± 0.019. The classification ability for breast tumor with textural information is satisfactory.

Conclusions

This system differentiates benign from malignant breast tumors with a good result and is therefore clinically useful to provide a second opinion.     

Evaluation of suspicious nipple discharge with MRI: review of 50 cases

Purpose

To determine the role of MRI in the evaluation and management of patients with suspicious nipple discharge and normal mammographic and US evaluation.

Patients and methods

A total of 50 patients with suspicious nipple discharge and normal mammographic and US evaluation prospectively underwent MRI. The first 16 patients underwent routine breast MRI, while MR-ductography with image fusion at the console was added for the last 34 patients.

Results

In 22 of 25 high-risk and malignant lesions, MRI showed enhancement whereas it was normal in three cases. In 25 benign cases (resolution of discharge/benign non-proliferative breast disease), MRI was negative in 22 cases and falsely positive in three cases.

Conclusion

In this clinical setting, MRI shows excellent sensitivity, PPV and NPV. A negative result on MRI would support clinical follow-up as opposed to surgery.     

Diffusion-weighted imaging of breast tumors: Differentiation of benign and malignant tumors

Objective

The aim of this study was to evaluate the role of diffusion-weighted images (DWI) in the differentiation between benign and malignant breast tumors.

Patients and methods

This study included 62 females with focal breast lesions according to mammography or sonomamography. All patients underwent dynamic contrast enhanced MRI (DCE-MRI), and DWI of the breast. The mean apparent diffusion coefficient (ADC) values were calculated for all lesions and were correlated with the final histopathological results. The sensitivity and specificity of DWI in the differentiation between benign and malignant breast tumors were calculated.

Results

Seventy-eight lesions were detected in the examined 62 patients included in this study. Fifty one lesions were benign and 27 lesions were malignant according to the final histopathological results. (25/27) lesions were correctly diagnosed by ADC as malignant lesions with mean ADC value (0.92 ± 0.23 × 10⁻³ mm²/s) which was significantly lower than the mean ADC value for benign tumors (1.46 ± 0.48 × 10⁻³ mm²/s) and was correctly diagnosed in (50/51) lesions. The sensitivity and specificity of DWI in the differentiation between benign and malignant breast tumors were 92.6% and 98%, respectively.

Conclusion

DWI offers a useful method for differentiation of benign and malignant breast lesions with high sensitivity and specificity. Being a short unenhanced scan DWI can be safely added to the standard breast MRI protocol.     

Comparative Analysis of Logistic Regression, Support Vector Machine and Artificial Neural Network for the Differential Diagnosis of Benign and Malignant Solid Breast Tumors by the Use of Three-Dimensional Power Doppler Imaging

Objective

Logistic regression analysis (LRA), Support Vector Machine (SVM) and a neural network (NN) are commonly used statistical models in computer-aided diagnostic (CAD) systems for breast ultrasonography (US). The aim of this study was to clarify the diagnostic ability of the use of these statistical models for future applications of CAD systems, such as three-dimensional (3D) power Doppler imaging, vascularity evaluation and the differentiation of a solid mass.

Materials and Methods

A database that contained 3D power Doppler imaging pairs of non-harmonic and tissue harmonic images for 97 benign and 86 malignant solid tumors was utilized. The virtual organ computer-aided analysis-imaging program was used to analyze the stored volumes of the 183 solid breast tumors. LRA, an SVM and NN were employed in comparative analyses for the characterization of benign and malignant solid breast masses from the database.

Results

The values of area under receiver operating characteristic (ROC) curve, referred to as Az values for the use of non-harmonic 3D power Doppler US with LRA, SVM and NN were 0.9341, 0.9185 and 0.9086, respectively. The Az values for the use of harmonic 3D power Doppler US with LRA, SVM and NN were 0.9286, 0.8979 and 0.9009, respectively. The Az values of six ROC curves for the use of LRA, SVM and NN for non-harmonic or harmonic 3D power Doppler imaging were similar.

Conclusion

The diagnostic performances of these three models (LRA, SVM and NN) are not different as demonstrated by ROC curve analysis. Depending on user emphasis for the use of ROC curve findings, the use of LRA appears to provide better sensitivity as compared to the other statistical models.     

Magnetic resonance imaging of breast vascularity in medial versus lateral breast cancer

Objective

Breasts with malignant tumors can demonstrate a general increased vascularity compared to the contralateral breast and a prominent blood vessel adjacent to the tumor on magnetic resonance imaging (MRI). The aim of the study was to further characterize these alterations in blood supply by location of the tumor within the breast using MRI.

Materials and methods

The study group included 105 patients who underwent breast MRI for suspicion of a malignancy over a 2-year period. Fifty-one had pathologically verified malignant tumors (study group), 11 had pathologically verified benign lesions (control), and 43 had negative scans (control). The malignant lesions were distinguished by location, medial or lateral, within the breast. Origin of the vascular supply and vessel diameter was recorded in a blinded manner. When available, MRI scans performed 2 years after treatment were reviewed as well.

Results

Of the 24 medial malignant tumors, 21 (87%) had a predominantly medial vascular supply and 3 (13%), a predominantly lateral supply; of the 23 lateral tumors, 11 (48%) had a predominantly medial vascular supply and 8 (35%), a predominantly lateral supply (p = 0.03). In 4 cases, no dominant vessel was noted. Maximum vessel diameter was 3.6 ± 1.1 mm in the patients with malignancy and 2.6 ± 0.8 mm in the controls (p < 0.0005). General increased vascularity was demonstrated in 91% of the medial tumor subgroup and 83% of the lateral tumor subgroup, as opposed to 36-37% in the control groups (p < 0.0005). Follow-up MRI, performed in 8 patients in the malignant-tumor group after treatment, revealed a considerable decrease in the prominent vessels, to a size close to that of the controls.

Conclusion

Breasts with malignant tumors are characterized by an altered general vascular supply, a prominent feeding vessel, and increased regional vascularity. Both the presence and location of the tumor affect the vascular supply. The vascular change apparently diminishes after treatment, although this finding requires further investigation in a larger sample.     

Contrast-enhanced ultrasound is helpful in the differentiation of malignant and benign breast lesions

Objective

To evaluate the significance of contrast-enhanced ultrasound (CEUS) examination in differential diagnosis of malignant and benign breast lesions.

Methods

Seventy-one patients with seventy-six breast tumors are selected randomly. CEUS examinations were performed before and after bolus injection of the contrast agent SonoVue (Bracco, Milan, Italy). Specific sonographic quantification software, Qontrast, was adopted to determine the morphology of vessels. Wash-in and wash-out parameters of each lesion were assessed for both procedures.

Results

The final histopathological findings distinguished 45 malignant and 31 benign from all of the lesions. Following SonoVue administration different perfusion phases could be identified: early (0-1 min), mid (1-4 min) and late (4-6 min) phases. In the early phase, CEUS identified 91.1% of malignant tumors characterized by a claw-shaped enhancement, while 83.9% of benign tumors had a homogeneous enhancement, with a statistically significant difference between the two enhancement patterns (χ² = 43.16, P < 0.01). Moreover, contrast medium persistence in the late phase was helpful in the identification of benign and malignant tumors (χ² = 46.88, P < 0.01): contrast medium was present in 88.9% of malignant tumors, while in only 9.7% of the benign tumors. The study showed that various parametric imaging color maps for peak intensity and time to peak were mostly suggestive of malignancy, while quite uniform peak intensity and time to peak of color maps were the characteristic of benign tumors. The study also found that malignant lesions presented with a higher maximum intensity signal than benign ones (P < 0.05) on the time-intensity curves.

Conclusions

CEUS cooperating with conventional US shows improved accuracy in differentiating between malignant and benign breast tumors. It could be a reliable diagnostic method of breast lesions.     

Differentiation between benign and malignant colon tumors using fast dynamic gadolinium-enhanced MR colonography; a feasibility study

Background

Colorectal cancer will present itself as a bowel obstruction in 16-23% of all cases. However, not all obstructing tumors are malignant and the differentiation between a benign and a malignant tumor can be difficult. The purpose of our study was to determine whether fast dynamic gadolinium-enhanced MR imaging combined with MR colonography could be used to differentiate a benign from a malignant obstructing colon tumor.

Methods

Patients with benign colon tumor stenosis, based on diverticulitis, were asked to participate in the study. The same number of patients with verified colorectal cancer was included. Both groups had to be scheduled for surgery to be included. Two blinded observers analyzed the tumors on MR by placing a region of interest in the tumor and a series of parameters were evaluated, e.g. wash-in, wash-out and time-to-peak.

Results

14 patients were included. The wash-in and wash-out rates were significantly different between the benign and malignant tumors, and a clear distinction between benign and malignant disease was therefore possible by looking only at the MR data. Furthermore, MR colography evaluating the rest of the colon past the stenosis was possible with all patients.

Conclusion

The results showed the feasibility of using fast dynamic gadolinium-enhanced MR imaging to differentiate between benign and malignant colonic tumors. With a high intra-class correlation and significant differences found on independent segments of the tumor, the method appears to be reproducible. Furthermore, the potential is big in performing a full preoperative colon evaluation even in patients with obstructing cancer. Trial number: NCT00114829.     

Value of contrast-enhanced ultrasound in the evaluation of indeterminate renal cysts on CT

Purpose

To demonstrate the value of contrast-enhanced ultrasound (CEUS) in the management of Bosniak type 2F and 3 renal cysts on CT.

Patients and methods

Retrospective study of 14 patients with 15 Bosniak type 2F and 3 renal cysts on contrast enhanced CT. All patients underwent CEUS of the kidneys after injection of SonoVue^®. Using predetermined criteria, the lesions were classified as benign, malignant or indeterminate. Patients either underwent surgery or follow-up CT at one to three years.

Results

From the 15 indeterminate cysts on CT, 12 were either benign (n = 8) or malignant (n = 4) on CEUS. From the eight cysts considered benign on CEUS, seven remained stable on follow-up CT after a minimum of one year interval and one was surgically resected and confirmed to be benign. All four cysts considered malignant on CEUS were surgically resected and three were confirmed to be malignant and one was confirmed to be benign. Three cysts were indeterminate: two lesions were surgically resected and one was benign while the other was malignant and one lesion was stable at one year follow-up CT.

Conclusion

CEUS was able to characterize indeterminate lesions as benign or malignant in 80% of cases with 92% reliability. Twenty percent of cysts remained indeterminate on CEUS. CEUS is reliable as a complement to CT in the evaluation of Bosniak type 2F and 3 renal cysts.     

Diagnosis of portal vein thrombosis discontinued with liver tumors in patients with liver cirrhosis and tumors by contrast-enhanced US: A pilot study

Aims

We assessed the role of contrast-enhanced ultrasound (CEUS) in the differential diagnosis between benign and malignant portal vein thrombosis (PVT) in patients who had liver tumors.

Methods

Seventeen consecutive patients who had cirrhosis, liver tumors, and PVT were prospectively studied with CEUS. CEUS was performed at low mechanical index after intravenous administration of a second-generation contrast agent (SonoVue, Bracco, Milan, Italy). Presence or absence of thrombus enhancement on CEUS were considered diagnostic for malignant or benign PVT. Five patients also underwent percutaneous portal vein fine-needle biopsy under US guidance. All patients were followed-up. Shrinkage of the thrombus and/or recanalization of the vessels on CDUS during follow-up were considered definitive evidence of the benign nature of the thrombosis, whereas the enlargement of the thrombus, disruption of the vessel wall, and parenchymal infiltration over follow-up were considered consistent with malignancy.

Results

Follow-up showed signs of malignant thrombosis in 14 of 17 patients. CEUS showed early arterial enhancement of the PVT in 14 patients of 14 malignant PVT, 1 patient of 3 benign PVT and the absence of thrombus enhancement in 2 patients of 3 benign PVT. FNB confirmed the results for malignant PVT in four of five patients, for benign granulomatous inflammation PVT in one of five patients in which CEUS showed early arterial enhancement of the PVT. The sensitivity, specificity and accuracy is 100%, 66.7% and 93.3% at diagnosis of malignant PVT using CEUS. In one patient with intrahepatic bile duct stone, CEUS were positive for malignant PVT, whereas FNB was negative (benign granulomatous inflammation PVT); follow-up examination confirmed benign PVT.

Conclusion

CEUS seems to be the pretty sensitive and specific test for diagnosing malignant portal vein thrombosis in patients with cirrhosis and tumors.     

Siliconomas mimicking cancer

Introduction

Silicone breast implants are widely used for breast augmentation and breast reconstruction following mastectomy. Implant rupture has specific radiological signs. With the advent use of new imaging technique such as positron emission tomography (PET) computed tomography (CT) and magnetic resonance imaging (MRI) of the breast, these signs may simulate malignancy.

Patients and methods

We retrospectively reviewed four cases of patients with silicon breast implants who arrive to the mammography clinic for further evaluation of a suspected malignant process demonstrated on either PET CT or breast MRI.

Results

Two cases were of PET CT performed for routine oncology follow-up of breast cancer. On both, the PET CT demonstrated multiple-spread benign silicone granulomas manifesting as multiple masses having an increase fluorodeoxyglucose (FDG) uptake. One case of a new mass was demonstrated as a suspicious mass on the dynamic sequences on MRI of the breast. Ultrasound-guided biopsy demonstrated benign tissue response to silicone. One case demonstrated bilateral ruptured breast implants on breast MRI, as well as bilateral axillary and mediastinal lymphadenopathy. Eventually, the patient underwent bronchoscopy for pulmonary workup of dry cough, revealing sarcoidosis.

Conclusion

Silicone granulomas can manifest as masses with suspicious morphology and enhancement dynamics on breast MRI or with increased FDG uptake on PET CT. The presence of silicone implants and awareness of the possibility of a rupture and formation of silicone granulomas may help in facilitating a correct diagnosis.     

Speckle reduction approach for breast ultrasound image and its application to breast cancer diagnosis

Objectives

To retrospectively evaluate the effects of a speckle reduction algorithm on radiologists’ diagnosis of malignant and benign breast lesions on ultrasound (US) images.

Methods

Using a database of 603 breast (US) images of 211 cases (109 benign lesions and 102 malignant ones), the original and speckle-reduced images were assessed by five radiologists and final assessment categories were assigned to indicate the probability of malignancy according to BI-RADS-US. The diagnostic sensitivity and specificity were investigated by the areas (Az) under the receiver operating characteristic (ROC) curves.

Results

The sensitivity and specificity of breast lesions on Ultrasound images improved from 88.7% to 94.3%, from 68.6% to 75.2%, respectively, and the area (Az) under ROC curve of diagnosis also increased from 0.843 to 0.939, Z = 4.969, there were significant differences in the Az between the original breast lesions and speckle-reduced ones on Ultrasound images (P < 0.001). The diagnostic accuracy of breast lesions had been highly improved from 78.67% to 92.73% after employing this algorithm.

Conclusions

The results demonstrate the promising performance of the proposed speckle reduction algorithm in distinguishing malignant from benign breast lesions which will be useful for breast cancer diagnosis.     

Solid non-invasive ovarian masses on MR: Histopathology and a diagnostic approach

Purpose

The purpose is to clarify the histopathology of the solid, non-invasive ovarian masses and to investigate the MR characteristics that distinguish benign from malignant.

Materials and methods

From 1996 to 2008, we identified 38 cases with predominantly solid non-invasive ovarian masses examined by contrast MR. We evaluated the signal intensity on T2WI and degree of contrast enhancement. In 31 of these cases with dynamic contrast study, we classified the enhancing patterns of the masses into gradually increasing and plateau after rapid increase patterns.

Result

Sixteen cases were benign sex-cord stromal tumors, three were other types of benign tumors, nine cases were diagnosed with primary malignant ovarian tumors, and 10 showed metastatic tumors. Low intensity on T2WI was observed in 15 benign and 2 malignant tumors. The gradually increasing pattern was observed in all 17 benignancies and 5 of the 14 malignancies. In the equilibrium phase, the masses were weakly enhanced in all 19 benignancies and only 4 of 19 malignancies. The diagnostic criteria, that low signal intensity masses with gradual weak enhancement are benign showed 93.3% accuracy and 100% positive predictive value.

Conclusion

Benign solid ovarian masses tended to show low signal intensity on T2WI and gradual weak enhancement.     

Breast ultrasound elastography—Results of 193 breast lesions in a prospective study with histopathologic correlation

Purpose

To evaluate the diagnostic performance of ultrasound elastography in breast masses.

Material and methods

193 lesions (129 benign, 64 malignant) were analyzed with the EUB 8500 Logos-ultrasonic-unit (Hitachi Medical, Japan) and a linear-array-transducer of 7.5-13-MHz. Standard of reference was cytology (FNAfine needle aspiration) or histology (core biopsy). The elastic-score was classified according to a 6-point colour-scale (Ueno classification; 1-3 = benign, 4-5 = malignant). Conventional B-mode ultrasound (US) findings were classified according to the BI-RADS classification. Statistical analysis included sensitivity, specificity, ROC-analysis and kappa-values for intra-/interobserver reliability.

Results

The mean score for elasticity was 4.1 ± 0.9 for malignant lesions, and 2.1 ± 1.0 for benign lesions (p < 0.001). With a best cut-off point between elasticity scores 3 and 4, sensitivity was 96.9%, and specificity 76%. Setting a best cut-off point for conventional US between BI-RADS 4 and 5, sensitivity was 57.8%, and specificity 96.1%. Elastography provided higher sensitivity and lower specificity than conventional US, but two lesions with elasticity score 1 were false negative, whereas no lesion scored BI-RADS 1-3 were false negative. ROC-curve was 0.884 for elastography, and 0.820 for conventional US (p < 0.001). Weighted kappa-values for intra-/interobserver reliability were 0.784/0.634 for BI-RADS classification, and 0.720/0.561 for elasticity scores.

Conclusion

In our study setting, elastography does not have the potential to replace conventional B-mode US for the detection of breast cancer, but may complement conventional US to improve the diagnostic performance.     

Analysis of perfusion weighted image of CNS lymphoma

Purpose

It is difficult to differentiate CNS lymphoma from other tumors such as malignant gliomas, metastases, or meningiomas with conventional MR imaging, because the imaging findings are overlapped between these tumors. The purpose of this study is to investigate the perfusion weighted MR imaging findings of CNS lymphomas and to compare the relative cerebral blood volume ratios between CNS lymphomas and other tumors such as high grade gliomas, metastases, or meningiomas.

Materials and methods

We retrospectively reviewed MRI findings and clinical records in 13 patients with pathologically proven CNS lymphoma between January 2006 and November 2008. We evaluated the relative cerebral blood volume ratios of tumor, which were obtained by dividing the values obtained from the normal white matter on MRI.

Results

Total 13 patients (M:F = 8:5; age range 46-67 years, mean age 52.3 years) were included. The CNS lymphomas showed relatively low values of maximum relative CBV ratio in most patients regardless of primary or secondary CNS lymphoma.

Conclusion

Perfusion weighted image may be helpful in the diagnosis of CNS lymphoma in spite of primary or secondary or B cell or T cell.     

Muscle fibers inside a fat tumor: A non-specific imaging finding of benignancy

Introduction

The differential diagnosis between benign and low-grade well-differentiated malignant lipomatous tumors might be very difficult for both the radiologist and the pathologist, although it has practical consequences. Among the criteria, muscular fibers detected inside the lesion are considered radiologically and histologically as a reliable sign of a benign intramuscular lipoma. New genetic criteria are now available. We report two cases of fat tumors containing muscular fibers both radiologically and histologically, but which are definitely malignant, considering genetic criteria.

Material and methods

Two cases of soft tissue fat tumors, containing muscular fibers on imaging examinations as well as histologically, had an aggressive behaviour, suggesting malignancy. Genetic criteria were therefore used to confirm the clinical impression.

Results

MDM2 and CDK4 confirmed the malignancy in the two cases.

Conclusion

Intra lesional muscular fibers detected on imaging or histological examinations should not be considered as a completely reliable sign of a benign intramuscular lipoma. In case of atypical clinical behaviour, genetic criteria should be used to prove the aggressiveness of the tumor.     

Radiologists' performance in the detection of benign and malignant masses with 3D automated breast ultrasound (ABUS)

Objectives

To retrospectively evaluate the detection performance of benign and malignant breast masses using 3D volume data obtained by ABUS and to determine lesion variables which affect detectability.

Methods

Between November and December of 2007, bilateral whole breast US images were obtained using ABUS in 67 consecutive women who were scheduled to undergo US-guided needle biopsy due to suspicious breast masses. Twenty-four invasive ductal cancers in 23 breasts, 46 benign breast lesions in 44 breasts and 38 normal breasts were included. Three breast radiologists (experience range, 8-16 years) who did not perform the examinations and were blinded to the histology independently reviewed the ABUS data of the 105 breasts to detect suspicious solid masses with pathology as the standard of reference. Sensitivity and specificity in detecting benign and malignant masses were calculated, and lesion characteristics affecting detectability were analyzed.

Results

Sensitivities for benign and malignant mass detections were 65.2% (30/46), 95.8% (23/24) for reader 1 (p = 0.007), 66.7% (31/46), 87.5% (21/24) for reader 2 (p = 0.087), and 56.3% (24/46), 91.7% (22/24), for reader 3 (p = 0.001), respectively. Logistic analysis showed that mass size (odds ratio, 95% CI; 1.12, 1.02-1.24), surrounding tissue changes (odds ratio, 95% CI; 0.11, 0.02-0.47), and shape of the mass (odds ratio, 95% CI; 3.12, 1.02-9.55) were the variables associated with detectability at ABUS.

Conclusion

In reader studies using ABUS data, significantly higher sensitivity was noted for malignant breast masses than for benign masses.     

Late sarcoma development after curettage and bone grafting of benign bone tumors

Background and aim

Rarely sarcomas develop in previous benign lesions, after a long term disease free interval. We report the experience on these rare cases observed at a single Institution.

Patients and methods

12 cases curetted and grafted, without radiotherapy developed sarcomas, between 1970 and 2005, 6.5-28 years from curettage (median 18, average 19).Age ranged from 13 to 55 years (median 30, average 32) at first diagnosis; tumors were located in the extremities (9 GCT, benign fibrous histiocytoma, ABC, and solitary bone cyst). Radiographic and clinic documentation, for the benign and malignant lesions, were available. Histology was available for 7 benign and all malignant lesions.

Results

To fill cavities, autogenous bone was used in 4 cases, allograft in 2, allograft and tricalcium-phosphate/hydroxyapatite in 1, autogenous/allograft in 1, heterogenous in 1. For 3 cases the origin was not reported. Secondary sarcomas, all high grade, were 8 osteosarcoma, 3 malignant fibrous histiocytoma, and 1 fibrosarcoma.

Conclusions

Recurrences with progression from benign tumors are possible, but the very long intervals here reported suggest a different cancerogenesis for these sarcomas. This condition is extremely rare accounting for only 0.26% of all malignant bone sarcomas treated in the years 1970-2005 and represents only 8.76% of all secondary bone sarcomas treated in the same years. This incidence is the same as that of sarcomas arising on fibrous dysplasia, and is lower than those arising on bone infarcts or on Paget's disease. This possible event must be considered during follow-up of benign lesions.