Developing a clinical scoring system to differentiate deep-seated atypical lipomatous tumor from lipoma of soft tissue (original) (raw)
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Magnetic Resonance Imaging Assessment of Lipomatous Soft-tissue Tumors
In Vivo, 2017
Aim: To establish the accuracy of magnetic resonance imaging (MRI) in distinguishing between benign and malignant lipomatous tumors; to evaluate the reproducibility of the MRI interpretation assessing the agreement between judgments of two radiologists with the same experience in soft-tissue sarcomas; to identify an association among MRI findings (size, depth, septa, nodules, signal homogeneity) and nature of the lesion. Materials and Methods: A total of 54 patients (28 men and 26 women), with a mean age of 56 (range=27-84) were included years. All subjects followed-up by the Multidisciplinary Sarcoma Group. The following MRI findings were judged in a blind study by two radiologists: size, localization, septa, nodules and signal homogeneity. A diagnostic indication was then given from among lipoma, atypical lipomatous tumour (ALT) and liposarcoma. Accuracy in distinguishing between benign and malignant lesions, and between lipoma and ALT (Fisher's exact test), inter-operator agreement (Cohen's kappa), association of MRI findings and malignancy of the lesion (Fisher's exact test and odds ratio) were evaluated. Results: The inter-operator agreement was complete (100%). The agreement between diagnostic hypothesis and histological diagnosis was statistically significant (p<0.05). Among the radiological findings taken into account, only septa and signal homogeneity were significantly associated with the malignancy of the lesion (p<0.05). Conclusion: MRI could be helpful in distinguishing lipomatous tumors, allowing biopsy to be avoided in some cases (negative predictive value=100%). Adipocytic tumors are tumors of mesenchymal origin, which can be either benign (lipoma, lipomatosis, etc.) or malignant (liposarcomas). Liposarcomas are rare tumors of mesenchymal origin and are the second most common subgroup of softtissue sarcomas in adults, with a peak age of incidence between the fifth and seventh decade (10-35%) (1, 2). In 2013, the World Health Organization (WHO) Committee for classification of soft-tissue tumors revised the classification, dividing the category of liposarcomas into five histological subtypes: well-differentiated (or atypical lipomatous tumor), dedifferentiated, myxoid, pleomorphic and mixed. This classification is a precise differentiation of morphological and biological activity of the disease, with a behavior that can range from non-metastatic atypical lipomatous tumors (ALT) or well-differentiated liposarcomas (WDLS) to high-grade tumors such as pleomorphic liposarcomas, which have a real risk of developing distant metastases (3-5). The most common subtype in the liposarcoma family is ALT, which accounts for about 40-45% (5, 6), and arises, without sex predilection, most frequently in the sixth decade of life, and can potentially be located in any region, with slight prevalence in the deep soft tissues of the limbs, especially in the thigh. The term 'atypical lipomatous tumor' is usually preferred to cases where the neoplasia is localized in the limbs, and the definition 'well-differentiated liposarcoma' is preferably used for tumors localized in the retroperitoneum or in the mediastinum. Biologically, this tumor is a locally aggressive subtype, without metastatic potential, unless areas of 387 This article is freely accessible online.
Non-Radiographic Risk Factors Differentiating Atypical Lipomatous Tumors from Lipomas
Frontiers in oncology, 2016
To determine non-radiographic risk factors differentiating atypical lipomatous tumors (ALTs) from lipomas. All patients with deep-seated lipomatous tumors of the extremities treated from January 2000 to October 2010 were retrospectively reviewed. Factors reviewed included age, gender, tumor location, size, histology, local recurrence, dedifferentiation, and metastasis. Multivariate logistic regression models were used to evaluate the effects of patient characteristics on ALT status. Ninety-four lipomas and 46 ALTs were included. Patients with an ALT were older (median: 60.5 vs. 55 years). Lipomas were evenly distributed between upper (48.9%) and lower extremities (51.1%), whereas ALTs predominately involved the lower extremities (91.3%). Median ALT size (22 cm) was greater than lipomas (10 cm), p < 0.0001. One lipoma (1.04%) recurred at 77 months and five ALTs (10.9%) recurred at an average of 39 months (19-64 months). Two ALTs originally treated with wide resection recurred with...
Lipomatous Tumors: A Comparison of MRI-Reported Diagnosis with Histological Diagnosis
Diagnostics
Lipomatous tumors are among the most common soft tissue tumors (STTs). Magnetic resonance imaging (MRI) is a state-of-the-art diagnostic tool used to differentiate and characterize STTs. Radiological misjudgment can lead to incorrect treatment. This was a single-center retrospective study. Two hundred and forty lipomatous tumors were included. MRI diagnoses were categorized as benign, intermediate, or malignant and were compared with histological diagnoses. Tumor volumes were measured by MRI and from surgical specimens. The tumor was correctly categorized 73.3% of the time. A total of 21.7% of tumors were categorized as more malignant in MRI reports than they were by histology, and vice versa for 5.0% of tumors. Volume measured by MRI was not different from actual tumor size in pathology. Atypical lipomatous tumors (ALTs) and liposarcomas (LPSs) were larger when compared with lipomata and occurred in older patients. Based on the MRI-suspected tumor entity, surgical treatment can be ...
Beyond the depths: deep-seated lipoma of the upper limb
European Journal of Plastic Surgery, 2013
Background Deep-seated lipomas are mature fat tissues which may occur in intermuscular, intramuscular, or submuscular locations. Unlike benign subcutaneous lipoma, which usually only grow on skin surface, deep-seated lipoma generally grow slowly and may sometimes infiltrate deeply and wrap around nerves. Methods A retrospective review of all patients with deepseated lipomas of the upper limb, operated on between 2002 and 2009 at our center, was carried out. Clinical and radiological characteristics, treatment, and evolution profile of these patients were also evaluated. Results Five patients were identified. The mean age of patients was 71 years (range 60 to 77 years). The mean follow-up period was 2 years and there was no recurrence after the surgery. Conclusions The complicated growing patterns of deepseated lipoma have brought about difficulties during diagnostic and surgical procedures. A marked similarity of physical characteristics between a deep-seated lipoma and other softtissue masses can cause several confusions, while a careless dissection can cause severe damage to nearby nerves. Level of Evidence: Level V, therapeutic study
Skeletal Radiology, 2012
Purpose To review the reliability of MR imaging features for the purpose of distinguishing lipoma and atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL). Materials and methods A retrospective review of 87 patients with histologically proven lipomatous tumors was performed. All underwent MR imaging, assessing lipomatous content, septation, and nodules. The associations between these features and tumor diagnosis based on morphology and the presence or absence of MDM2 amplification were explored. The age of the patient and the size and location of the lesion were also recorded for statistical analysis. Results Of the 87 patients, 54 were classified as lipomas and 33 as ALT/WDL. MR identified ALT/WDL with a sensitivity of 90.9 % (CI 74.5-97.6) and a specificity of 37.0 % (CI 24.6-51.3). The positive and negative predictive values were 46.9 % (CI 34.5-59.7) and 86.9 % (CI 65.3-96.6), respectively. The mean age of patients with ALT/WDL was greater (60 years [range 40-83 years]) than those with lipoma (52 years [range 10-79 years]) (p00.025). The mean size of ALT/WDL (18.7 cm [range 5-36 cm]) was significantly greater than lipoma (13.9 cm [range 3-32 cm]) (p0 0.003). Features that increased the likelihood of ALT/WDL included: patient age over 60 years, maximal lesion dimension over 10 cm, location in lower limb, and presence of non-fatty areas, by a factor of 2.61-6.25 times. Conclusions ALT/WDL and lipoma have overlapping MR imaging characteristics. The most reliable imaging discriminators of ALT/WDL were size of lesion and lipomatous content, but due to the overlap in the MRI appearances of lipoma and ALT/WDL, discrimination should be based on molecular pathology rather than imaging.
American Journal of Surgical Pathology, 2010
Ancillary molecular testing has been advocated for diagnostic accuracy in the differentiation of lipomas from atypical lipomatous tumors/well-differentiated liposarcomas (ALT/WDL); however, the implications and specific indications for use are not well-established in the current literature. Herein, we extend previous findings by quantitatively evaluating the impact of molecular testing of lipomatous neoplasms in our routine clinical practice, how it modifies the historical perspective of their clinical course, and the effect of distinct surgical procedures in modulating the risk of local recurrence for these tumors after molecular classification. On the basis of these analyses, we suggest a specific set of basic recommendations for complementary molecular assessment in the diagnosis of lipomatous tumors. Four hundred and five lipomatous neoplasms located in the trunk and extremities were analyzed histologically and for the presence of 12q13-15 amplification on paraffin-embedded tissues by assessing MDM2/CPM amplification. Survival analyses were calculated with Kaplan-Meier and compared with the log-rank. Multivariate analysis was evaluated by the Cox regression method. The 405 tumors were histologically classified as ordinary lipoma (n = 324), intramuscular lipoma (n = 29), and ALT/WDL (n = 52). The level of agreement between the histologic diagnosis and the molecular diagnosis was high (96%) but pathologists showed a tendency to overestimate cytologic atypia and the diagnosis of ALT/WDL (precision, 79%; accuracy, 88%). Molecular assessment led to a major diagnostic reclassification in 18 tumors (4%). Eleven of the tumors histologically classified as ALT/WDL were reclassified as ordinary lipoma (n = 5) and intramuscular lipoma (n = 6); none of which recurred. Seven ordinary lipomas were reclassified as ALT/WDL, 6 of which were larger than 15 cm and deeply located; 2 recurred locally. After molecular data, the 5-year local recurrence rates for ordinary lipoma, intramuscular lipoma, and ALT/WDL were 1%, 12%, and 44%, respectively. Multivariate analyses after molecular assessment showed tumor type and type of resection to be associated with the risk of local recurrence. Complementary molecular testing refines the histologic classification of lipomatous tumors and better estimates the impact of surgical procedures on the risk of local recurrence. Pathologists tend to overestimate the degree of cytologic atypia and the indiscriminate use of molecular testing should be avoided, especially for extremity-based tumors. Molecular testing should be considered for ''relapsing lipomas,'' tumors with questionable cytologic atypia (even if widely excised), or for large lipomatous tumors (>15 cm) without diagnostic cytologic atypia.
Insights into Imaging, 2011
Objective To retrospectively analyse the magnetic resonance (MR) findings of subcutaneous lipomatous soft-tissue tumours (SLSTT) in order to define a diagnostic and therapeutic strategy. Methods The MR findings of 46 SLSTT were registered for the following data: area, location within the subcutaneous compartment, dimensions, shape and delineation, signal intensity (SI) on different pulse sequences, signal homogeneity, degree and pattern of contrast enhancement. The MR findings, together with patients' age and gender, were compared with histopathological findings. Results Sixty-eight percent of the lipomas had a homogeneous T1-SI identical to the SI of subcutaneous fat. Heterogeneity in other lipomas was due to fat necrosis and small septa. Other lesions with homogeneous T1-SI identical to the SI of subcutaneous fat included lipoblastoma, lipomatosis and lipoma-like hibernoma. None of the liposarcomas were homogeneous and isointense to SI of subcutaneous fat on T1-weighted imagin...
Scientific Reports
Suspicion of malignant change within a lipoma is a common and increasing workload within the UK Sarcoma multidisciplinary team (MDT) network, and a source of considerable patient anxiety. Currently, there is no lipoma-specific data, with regard to which clinical or radiographic features predict non-benign histology, or calculate an odds-ratio specific to a lipomatous lesion being non-benign. We performed a 9-year, double-blind, unmatched cohort study, comparing post-operative histology outcomes (benign versus non-benign) versus 15 signs across three domains: Clinical (size of tumour, depth, growth noticed by patient, previous lipoma, patient felt pain), Ultrasonographic (size, depth, vascularity, heterogenous features, septae) and MRI (size, depth, vascularity, heterogenous features, septae, complete fat signal suppression). Receiver operating characteristic (ROC) analysis, odds ratios and binary logistic regression analysis was performed double-blind. When each sign is considered i...
Lipomatous tumors of soft tissue: MR appearance with histological correlation
European Journal of Radiology, 2004
There is a broad spectrum of lipomatous tumors that involve soft tissues including ordinary lipomas, variants of lipomas, heterotopic lipomas, lipomatosis, hibernomas and liposarcomas. The recognition of these tumors is important to avoid diagnostic pitfalls. The MR imaging appearance of the lesion, including location, shape and internal architecture, suggests the diagnosis of lipomatous tumors. The signal intensity on T1-, T2-, fat-suppressed T2-weighted (FS-T2) images or short tau inversion recovery (STIR), T1-and fat-suppressed T1-weighted images after Gd-DTPA administration can be a useful aid in distinguishing between biologically different types of lipomatous tumors. The imaging features are often characteristic and reflect the histological pattern of the tumors.
Sarcoma, 2018
Extremity lipomas and well-differentiated liposarcomas (WDLs) are difficult to distinguish on MR imaging. We sought to evaluate the accuracy of MRI interpretation using MDM2 amplification, via fluorescence in-situ hybridization (FISH), as the gold standard for pathologic diagnosis. Furthermore, we aimed to investigate the utility of a diagnostic formula proposed in the literature. We retrospectively collected 49 patients with lipomas or WDLs utilizing MDM2 for pathologic diagnosis. Four expert readers interpreted each patient's MRI independently and provided a diagnosis. Additionally, a formula based on imaging characteristics (i.e. tumor depth, diameter, presence of septa, and internal cystic change) was used to predict the pathologic diagnosis. The accuracy and reliability of imaging-based diagnoses were then analyzed in comparison to the MDM2 pathologic diagnoses. The accuracy of MRI readers was 73.5% (95% CI 61-86%) with substantial interobserver agreement (=0.7022). The for...