Diagnostic imaging in lipedema: A systematic review.

BACKGROUND: Diagnosing lipedema remains a challenge due to its heterogeneous presentation, co-existing diseases, and the lack of objective diagnostic imaging. OBJECTIVE: This systematic review aims to outline the currently available diagnostic imaging methods to characterize lipedema in the legs along with their diagnostic performance. METHODS: PubMed, Embase, Google Scholar, Scopus, and Web of Science were searched. The quality assessment of diagnostic accuracy studies (QUADAS) tool was used for quality assessment. RESULTS: Thirty-two studies describing a total of 1154 patients with lipedema were included for final analysis. Features for lipedema have been defined using ultrasound (increased subcutaneous adipose tissue), lymphoscintigraphy (slowing of the lymphatic flow and a frequent asymmetry between the lower extremities), computed tomography (symmetrical bilateral soft tissue enlargement without either skin thickening or subcutaneous edema), magnetic resonance imaging (increased subcutaneous adipose tissue), MR lymphangiography (enlarged lymphatic vessels up to a diameter of 2 mm), and dual-energy X-ray absorptiometry (fat mass in the legs adjusted for body mass index (BMI) ≥ 0.46 or fat mass in the legs adjusted for total fat mass ≥ 0.384). CONCLUSION: The diagnostic performance of currently available imaging modalities for assessing lipedema is limited. Prospective studies are needed to evaluate and compare the diagnostic performance of each imaging modality. Imaging techniques focusing on the pathogenesis of the disease are needed.

Differentiation of lipoedema from bilateral lower limb lymphoedema by imaging assessment of indocyanine green lymphography.

Lipoedema is characterized by disproportionate painful fat accumulation mostly in the lower limbs. The presence of lymphoedema in lipoedema remains controversial. This study aimed to assess the presence or absence of lymphoedema in the lower limbs of women with lipoedema using indocyanine green (ICG) lymphography. A cross-sectional retrospective study was undertaken in women with a clinical diagnosis of lipoedema whose lower limbs were examined with ICG lymphography. MD Anderson Cancer Center (MDACC) ICG staging was used to determine lymphoedema presence and severity. Patient characteristics, ICG lymphography findings, Stemmer sign, body mass index, waist-to-hip ratio, limb volume and bioimpedance spectroscopy measures were recorded. Forty women with lipoedema underwent ICG lymphography for the lower limbs from January 2018 to July 2022. Thirty-four women (85.0%) were determined by ICG lymphography as MDACC ICG Stage 0 representing normal lymphatics. Of the six women who demonstrated dermal backflow on ICG lymphography, all were determined as ICG Stage 1, four had localized traumatic dermal backflow area at their ankles, one had previously diagnosed with primary lymphoedema and one was classified as lipoedema stage 4. ICG lymphography findings suggested the absence of lymphoedema in a clear majority of women with lower limb lipoedema.

Subcutaneous Adipose Tissue Edema in Lipedema Revealed by Noninvasive 3T MR Lymphangiography.

BACKGROUND: Lipedema exhibits excessive lower-extremity subcutaneous adipose tissue (SAT) deposition, which is frequently misidentified as obesity until lymphedema presents. MR lymphangiography may have relevance to distinguish lipedema from obesity or lymphedema. HYPOTHESIS: Hyperintensity profiles on 3T MR lymphangiography can identify distinct features consistent with SAT edema in participants with lipedema. STUDY TYPE: Prospective cross-sectional study. SUBJECTS: Participants (48 females, matched for age [mean = 44.8 years]) with lipedema (n = 14), lipedema with lymphedema (LWL, n = 12), cancer treatment-related lymphedema (lymphedema, n = 8), and controls without these conditions (n = 14). FIELD STRENGTH/SEQUENCE: 3T MR lymphangiography (nontracer 3D turbo-spin-echo). ASSESSMENT: Review of lymphangiograms in lower extremities by three radiologists was performed independently. Spatial patterns of hyperintense signal within the SAT were scored for extravascular (focal, diffuse, or not apparent) and vascular (linear, dilated, or not apparent) image features. STATISTICAL TESTS: Interreader reliability was computed using Fleiss Kappa. Fisher's exact test was used to evaluate the proportion of image features between study groups. Multinomial logistic regression was used to assess the relationship between image features and study groups. The odds ratio (OR) and 95% confidence interval (CI) of SAT extravascular and vascular features was reported in groups compared to lipedema. The threshold of statistical significance was P < 0.05. RESULTS: Reliable agreement was demonstrated between three independent, blinded reviewers (P < 0.001). The frequency of SAT hyperintensities in participants with lipedema (36% focal, 36% diffuse), LWL (42% focal, 33% diffuse), lymphedema (62% focal, 38% diffuse), and controls (43% focal, 0% diffuse) was significantly distinct. Compared with lipedema, SAT hyperintensities were less frequent in controls (focal: OR = 0.63, CI = 0.11-3.41; diffuse: OR = 0.05, CI = 0.00-1.27), similar in LWL (focal: OR = 1.29, CI = 0.19-8.89; diffuse: OR = 1.05, CI = 0.15-7.61), and more frequent in lymphedema (focal: OR = 9.00, CI = 0.30-274.12; diffuse: OR = 5.73, CI = 0.18-186.84). DATA CONCLUSION: Noninvasive MR lymphangiography identifies distinct signal patterns indicating SAT edema and lymphatic load in participants with lipedema. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.

Lymphatic function and anatomy in early stages of lipedema.

OBJECTIVE: Lipedema is an inflammatory subcutaneous adipose tissue disease that develops in women and may progress to lipolymphedema, a condition similar to lymphedema, in which lymphatic dysfunction results in irresolvable edema. Because it has been shown that dilated lymphatic vessels, impaired pumping, and dermal backflow are associated with presymptomatic, cancer-acquired lymphedema, this study sought to understand whether these abnormal lymphatic characteristics also characterize early stages of lipedema prior to lipolymphedema development. METHODS: In a pilot study of 20 individuals with Stage I or II lipedema who had not progressed to lipolymphedema, lymphatic vessel anatomy and function in upper and lower extremities were assessed by near-infrared fluorescence lymphatic imaging and compared with that of a control population of similar age and BMI. RESULTS: These studies showed that, although lower extremity lymphatic vessels were dilated and showed intravascular pooling, the propulsion rates significantly exceeded those of control individuals. Upper extremity lymphatics of individuals with lipedema were unremarkable. In contrast to individuals with lymphedema, individuals with Stage I and II lipedema did not exhibit dermal backflow. CONCLUSIONS: These results suggest that, despite the confusion in the diagnoses between lymphedema and lipedema, their etiologies differ, with lipedema associated with lymphatic vessel dilation but not lymphatic dysfunction.

Lower extremity lymphatic function predicted by body mass index: a lymphoscintigraphic study of obesity and lipedema.

BACKGROUND/OBJECTIVES: Patients with obesity and lipedema commonly are misdiagnosed as having lymphedema. The conditions share phenotypic overlap and can influence each other. The purpose of this study was to delineate obesity-induced lymphedema, obesity without lymphedema, and lipedema in order to improve their diagnosis and treatment. SUBJECTS/METHODS: Our Lymphedema Center database of 700 patients was searched for patients with obesity-induced lymphedema (OIL), obesity without lymphedema (OWL), and lipedema. Patient age, sex, diagnosis, cellulitis history, body mass index (BMI), and treatment were recorded. Only subjects with lymphoscintigraphic documentation of their lymphatic function were included. RESULTS: Ninety-eight patients met inclusion criteria. Subjects with abnormal lymphatic function (n = 46) had a greater BMI (65 ± 12) and cellulitis history (n = 30, 65%) compared to individuals with normal lymphatic function [(BMI 42 ± 10); (cellulitis n = 8, 15%)] (p < 0.001). Seventeen patients had a history of lipedema and two exhibited abnormal lymphatic function (BMI 45, 54). The risk of having lower extremity lymphedema was predicted by BMI: BMI < 40 (0%), 40-49 (17%), 50-59 (63%), 60-69 (86%), 70-79 (91%), ≥80 (100%). Five patients with OIL (11%) underwent resection of massive localized lymphedema (MLL) or suction-assisted lipectomy. Three individuals (18%) with lipedema were treated with suction-assisted lipectomy. CONCLUSIONS: The risk of lymphedema in patients with obesity and lipedema can be predicted by BMI; confirmation requires lymphoscintigraphy. Individuals with OIL are at risk for cellulitis and MLL. Patients with a BMI > 40 are first managed with weight loss. Excisional procedures can further reduce extremity size once BMI has been lowered.

Uncovering Lymphatic Transport Abnormalities in Patients with Primary Lipedema.

BACKGROUND: Although lipedema is often clinically distinguished from lymphedema, there is considerable overlap between the two entities. The purpose of this study was to evaluate lymphoscintigraphic findings in patients with lipedema to better characterize lymphatic flow in this patient population. METHODS: Patients with lipedema receiving lymphoscintigraphy between January 2015 and October 2017 were included. Patient demographics, clinical characteristics, and lymphoscintigraphic findings were extracted. Klienhan's transport index (TI) was utilized to assess lymphatic flow in patient's lower extremities (LEs).Scores ranged from 0 to 45, with values > 10 denoting pathologic lymphatic transport. RESULTS: A total of 19 total patients with lipedema underwent lymphoscintigraphic evaluation. Mean age was 54.8 years and mean body mass index was 35.9 kg/m2. Severity of lipedema was classified as stage 1 in five patients (26.3%), stage 2 in four patients (21.1%), stage 3 in four patients (21.1%), and stage 4 in six patients (31.6%). The mean TI for all extremities was 12.5; 24 (63.2%) LEs had a pathologic TI, including 7 LEs with stage 1 (29.2%), 3 LEs with stage 2 (12.5%), 6 LEs with stage 3 (25.0%), and 8 LEs with stage 4 lipedema (33.3%). The mean TI was significantly greater for extremities with severe (stage 3/4) lipedema than those with mild or moderate (stage 1/2) lipedema (15.1 vs. 9.7, p = 0.049). Mean difference in TI scores between each LE for individual patients was 6.43 (standard deviation +7.96). CONCLUSION: Our results suggest that patients with lipedema have impaired lymphatic transport, and more severe lipedema may be associated with greater lymphatic transport abnormalities.

Lymphoscintigraphic findings in patients with lipedema. / Hallazgos linfogammagráficos en pacientes con lipedema.

INTRODUCTION: Lipedema is a syndrome that is characterised by edema, an accumulation of fat, pain and haematomas in the lower limbs that principally affects women. Diagnosis is currently based on clinical criteria, since there is no accurate diagnostic imaging for the condition. The aim of our study was to describe the lymphoscintigraphic findings in patients with lipedema. MATERIAL AND METHOD: A prospective cohort study of women with clinical criteria of lipedema who underwent lymphoscintigraphy. Two independent nuclear physicians described and classified the lymphoscintigraphy findings in different grades of severity, according to the migration and distribution of the radiopharmaceutical. Eighty three patients were included with a median age of 49.7years (range: 18-80) and a mean body mass index (BMI) of 29.9kg/m2 (95%CI: 28.4-31.3) RESULTS: Lymphoscintigraphy showed alterations in 47% of the patients, most were low (35.9%) or low-moderate grade (48.7%). None of the patients were severely affected (no migration of the radiopharmaceutical). The degree of lymphoscintigraphic involvement bore no relation to age (P=.674), Stemmer's sign (P=.506), or BMI (P=.832). We found lymphoscintigraphy findings in all the clinical stages of lipedema, with no significant differences between the grade of lymphoscintigraphic involvement and the clinical stage of lipedema (P=.142). CONCLUSION: Although lymphoscintigraphy has been used to differentiate lipedema from lymphedema, we found frequent alterations in the patients with lipedema, therefore the presence of findings dues not discount a diagnosis of lip1aedema.

Subcutaneous adipose tissue therapy reduces fat by dual X-ray absorptiometry scan and improves tissue structure by ultrasound in women with lipoedema and Dercum disease.

Lipoedema is painful nodular subcutaneous adipose tissue (SAT) on legs and arms of women sparing the trunk. People with Dercum disease (DD) have painful SAT masses. Lipoedema and DD fat resists loss by diet and exercise. Treatments other than surgery are needed. Six women with lipoedema and one with DD underwent twelve 90-min sessions over 4 weeks. Body composition by dual X-ray absorptiometry scan, leg volume, weight, pain, bioimpedance, tissue size by caliper and ultrasound were analysed before and after SAT therapy by paired t-tests. There was a significant decrease from baseline to end of treatment in weight, 87.6 ± 21 to 86.1 ± 20.5 kg (P = 0.03), leg fat mass 17.8 ± 7.7 to 17.4 ± 7.6 kg (P = 0.008), total leg volume 12.9 ± 4 to 12 ± 3.5 L (P = 0.007), six of 20 calliper sites and tissue oedema. Pain scores did not change significantly. By ultrasound, six women had 22 hyperechoic masses in leg fat that resolved after treatment; five women developed seven new masses. Fascia improved by ultrasound after treatment. SAT therapy reduced amount and structure of fat in women with lipoedema and Dercum disease; studies are needed to compare SAT therapy to other therapies.