Machine learning and magnetic resonance imaging: Differentiating benign from malignant osseous tumors.

Radiomics and machine learning applied to the isolated cartilaginous bone lesion on magnetic resonance imaging (MRI) is increasingly useful to distinguish malignant versus benign bone lesions, to determine whether repetitive imaging over time, to determine dynamic expansion, or immediate excisional biopsy are indicated.

Outcomes and Complications of Corticosteroid Injection of Rheumatoid Nodules.

Objective: Rheumatoid nodules (RN), a classic cutaneous extra-articular manifestation of rheumatoid arthritis, can often cause discomfort or cosmetic embarrassment. This research determined the effectiveness and complications of corticosteroid injection of the RN. Methods: Using a repeated measure design, 66 consecutive symptomatic RN were measured, underwent corticosteroid injection with 1 to 2mL of a 50:50 mixture of 1% lidocaine and triamcinolone acetonide (20-40mg), and then reassessed at four months for softening, reduction in size, and complications, including infection. Results: The mean age of our patient group was 53.3±10.6 years; 45 percent were Hispanic, 55 percent were non-Hispanic White, 100 percent were seropositive (rheumatoid factor and/or anti-CCP antibody), and 87.5 percent were female. Baseline mean RN diameter was 0.50±0.51cm and four months after injection was reduced to 0.29±0.33cm (decreased 42% or 0.21±0.57cm reduction, 95% CI: 0.46 <0.21< 0.37, p=0.013), 100 percent (66/66) were less painful, and 77 percent (51/66) were palpably softened. However, 70 percent (46/66) demonstrated cutaneous atrophy and/or hypopigmentation at four months, 53 percent (35/66) nodules recurred within 12 months, and 47 percent (31/66) nodules were eventually surgically removed. Limitations: Two (3%) of the larger RN (2.5cm on the olecranon and 2cm on the 2nd toe) became infected and failed antibiotic therapy, necessitating surgical excision for complete resolution. Conclusion: For short-term symptomatic relief, smaller RN can be safely injected with triamcinolone. Large symptomatic RN (≥2cm) are at greater risk of infection; thus, in these cases, lower corticosteroid doses or surgical excision may be preferred. In the long-term, effective systemic antirheumatic therapy with treat-to-target is the best approach.

Systemic sclerosis in Native Americans of the American Southwest.

OBJECTIVE: Many indigenous non-Caucasian populations, including Native Americans, have been reported to have higher rates, distinct clinical phenotypes, increased complications, and greater severity of systemic sclerosis (SSc). However, little is known of SSc specifically in Native Americans of the American Southwest. This study compared the clinical and serologic manifestations and outcomes of SSc in Native Americans and non-Native Americans (non-Natives) of this region. METHODS: This cross-sectional retrospective study included 137 SSc patients (109 [80%] were non-Native and 28 [20%] were Native Americans) followed over a mean of 11.5 ± 7.6 years. Participants were repetitively evaluated with medical history, physical examination, echocardiography, chest imaging, and serologic testing. Disease characteristics and outcomes were statistically compared between Native Americans and non-Native patients. RESULTS: The estimated prevalence of SSc in Native Americans was 40.0 cases/100 000 vs 17.1 cases/100 000 for non-Natives (odds ratio 2.34, 95% confidence interval [CI] 1.55-3.55, P < .001). The cohorts were similar in terms age, age of onset, limited vs diffuse cutaneous SSc, telangiectasias, gastroesophageal reflux disease, Raynaud phenomenon, serologies, interstitial lung disease, pulmonary arterial hypertension, scleroderma renal crisis, cancer prevalence, and overall mortality (all P > .05). However, for Native Americans, mortality specifically from fatal infections was 3.94-fold that of non-Natives (hazard ratio 6.88, 95% CI 1.37-34.64; P < .001). CONCLUSION: In Native Americans of the American Southwest, SSc is increased in prevalence but is phenotypically similar to SSc in non-Natives. However, mortality due specifically to infection is increased in Native Americans with SSc.

Systemic sclerosis manifestations and clinical outcomes in Hispanics/Latinos of the American Southwest.

Objective: Certain Hispanic/Latino (Hispanic) populations have been reported to have higher rates and severity of systemic sclerosis; however, little is known of systemic sclerosis in the American Southwest. This study compared manifestations of systemic sclerosis in Hispanics with non-Hispanics of New Mexico. Methods: This cross-sectional longitudinal study included 109 systemic sclerosis patients followed over a mean of 12.6 ± 8.9 years. Subjects were repetitively evaluated including physical examination, echocardiography, chest imaging, and serologic testing and observed for complications. Disease characteristics and long-term outcomes were statistically compared between self-identified Hispanic and non-Hispanic subjects. Results: A total of 73 (67%) systemic sclerosis subjects were Hispanic and 36 (33%) were non-Hispanic. The cohorts were similar in mean age, age of systemic sclerosis onset, limited versus diffuse cutaneous systemic sclerosis, telangiectases, gastroesophageal reflux disease, Raynaud's phenomenon, autoantibody profile, interstitial lung disease, pulmonary hypertension, scleroderma renal crisis, mortality, and comorbid malignancy (all p > 0.05). However, the standardized mortality ratio was increased in both cohorts relative to age-adjusted mortality: Hispanic: 2.08, confidence interval (1.94-2.24); non-Hispanic: 1.56, confidence interval (1.46-1.68). Furthermore, the standardized incidence ratio for malignancy was increased in both cohorts: Hispanic: 1.45, confidence interval (1.35-1.56); non-Hispanic: 1.24, confidence interval (1.16-1.34). The mean age of cancer diagnosis occurred at a significantly younger age in Hispanics (Hispanics: 53.1 ± 9.7 years; non-Hispanics 63.7 ± 7.9 years; 95% confidence interval: -19 ⩽ 10.6 ⩽ 2.2; p = 0.016). Conclusion: Systemic sclerosis phenotype, autoantibodies, complications, outcomes, malignancy rates, and mortality are generally similar between Hispanics and non-Hispanics with systemic sclerosis in the American Southwest. However, age-adjusted comorbid malignancy and mortality rates are significantly increased in both groups.

Statin-associated immune-mediated necrotizing myositis in Native Americans.

OBJECTIVES: Statin-associated immune-mediated necrotizing myopathy (IMNM) and idiopathic inflammatory myositis (IIM) are myopathies with overlapping features. This study compared the manifestations of IMNM to IIM in Native Americans. METHOD: Twenty-one Native American patients with inflammatory myopathy (IM) were characterized as to diabetes mellitus, hyperlipidaemia, statin exposure, myopathy diagnosis, muscle histology, autoimmune and myositis-specific autoantibodies, therapy and outcome. RESULTS: IM consisted of 52.4% IMNM, 42.9% IIM and 4.8% metabolic myopathy. IMNM vs IIM patients were older [61.6 years (s.d. 9.8) vs 39.8 (14.3)], diabetes mellitus (100% vs 55.6%), hyperlipidaemia (100% vs 33.3%), statin-exposure (100% vs 22.2%), creatine kinase [CK; 11 780 IU (s.d. 7064) vs 1707 (1658)], anti-3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) antibodies (85.7% vs 11.1%) and necrotizing IM (81.8% vs 11.1%), but shorter disease duration [26.2 months (s.d. 395) vs 78.4 (47.9)], RP (9.1% vs 55.6%), cutaneous manifestations (0% vs 55.6%), ANA (18.2% vs 66.7%) or any autoantibody (18.2% vs 88.9%) (all P < 0.05). MRI abnormalities, histologic IM, myositis-specific autoantibodies, pulmonary hypertension, oesophageal dysfunction, interstitial lung disease, disability and persistently elevated CK were similar. IMNM vs IIM was treated more with IVIG (72.7% vs 11.1%; P = 0.009) and less with antimetabolites (45.5% vs 88.9%; P = 0.05) and rituximab (18.2% vs 55.6%; P = 0.09). CONCLUSIONS: IMNM may occur in Native Americans and is associated with diabetes mellitus, hyperlipidaemia, statin use and older age and is characterized by marked CK elevation, necrotizing myopathy and anti-HMGCR antibodies with few cutaneous or vascular manifestations.

Intraarticular injection of the interphalangeal joint for therapy of digital mucoid cysts.

Mucoid cysts are associated with osteoarthritis (OA) of the digital joints and frequently recur after needle drainage, injection, or surgical ablation. This study determined whether intraarticular injection of the adjacent interphalangeal joint rather than the cyst itself might be effective in resolving digital mucoid cysts. Using paired case series design and sterile technique, 25 consecutive OA digital joints with an adjacent mucoid cyst underwent dorsal non-transtendinous intraarticular injection with a 25-gauge needle and 20-mg triamcinolone acetonide, followed by puncture and manual expression of cyst fluid. Patient pain was measured with the 10-cm Visual Analogue Pain Scale prior to the procedure and at 6 months. Cyst resolution was determined at 6 months and 3 years. The subjects were 61.0 ± 7.7 years old and 60% (15/25) female. Mucoid cysts were adjacent to 19 distal interphalangeal, 3 metacarpophalangeal, and 3 interphalangeal joints. Pre-procedural pain was 4.7 ± 1.0; procedural pain was 6.2 ± 0.6 cm, and post-procedural pain at 6 months was 1.2 ± 0.8 cm (74.5% reduction, 95% CI of difference: 3.0 < 3.5 < 4.0 (p < 0.0001)). 84% (21/25) of the cysts resolved at 6 months; however, 60% (15/25) of the mucoid cysts recurred within 3 years and required retreatment (14 adjacent joints re-injected and 1 ablative cyst surgery). No complications were noted. Intraarticular corticosteroid injection using a dorsal non-transtendinous approach of the joint adjacent to a mucoid cyst is effective resolving cysts and reducing pain at 6 months; however, 60% of mucoid cysts reoccur within 3 years and may require reinjection or surgery.Trial registration: This was not a clinical trial.

Development of Lupus Erythematosus Tumidus During the Course of Systemic Sclerosis.

A man with systemic sclerosis (SS), manifested by characteristic skin lesions, gastro-esophageal reflux disease, and pulmonary fibrosis producing progressive respiratory failure, and a positive antinuclear antibody consistent with reactivity to fibrillarin, developed skin lesions with the clinical and histological characteristics of lupus erythematosus tumidus (LET) 10 years after the diagnosis of SS. His respiratory failure progressed and he expired from sepsis after tracheal intubation and mechanical ventilation two years after developing LET. The association of SS and LET, not described until now, raises questions about its pathogenesis and its prognostic significance.

Atypical Chronic Inflammatory ANCA-Positive Deforming Arthritis After Cocaine-Levamisole Exposure.

BACKGROUND/OBJECTIVE: Immunostimulatory drugs including immune checkpoint inhibitors and levamisole can induce inflammatory disease including vasculitis, rashes, tissue necrosis, and arthritis. METHODS: This prospective cohort study determined the 5-year outcomes of cocaine-levamisole-induced inflammatory disease as to outcomes and survival. Thirty-one consecutive cocaine-levamisole autoimmune patients and 45 primary vasculitis patients were characterized as to clinical differentiating features, antineutrophil cytoplasmic antibody (ANCA) status, treatment, the presence of acute and chronic arthritis, and 5-year outcome. RESULTS: Seventy-one percent (22/31) of cocaine-levamisole vasculopathy cases were ANCA positive (86% p-ANCA and 14% c-ANCA), whereas 53% (23/45) of the primary vasculitis were ANCA positive (p = 0.04). The ANCA-positive cocaine-levamisole cohort at onset were characterized by younger age (45 ± 12 vs 53 ± 14 years, p = 0.04), superficial skin necrosis (82% vs 54%, p = 0.036), depressed complement C3 (27% vs 4%, p = 0.33), antiphospholipid antibodies (50% vs 4%, p < 0.001), neutropenia (18% vs 0%, p = 0.044), and elevated antimyeloperoxidase (MPO) antibody levels (100% vs 67%, p < 0.001). Chronic cocaine-levamisole disease was characterized by severe cicatrical deformities of the face and extremities (45.5% vs 8.3%, p = 0.005). Arthralgias (71% vs 82%, p = 0.19) and acute arthritis (33% vs 32%, p = 0.25) were similar between the 2 groups. However, a substantial proportion cocaine-levamisole-induced autoimmune patients (18% vs 0%, p = 0.045) developed a chronic deforming inflammatory arthritis that was rheumatoid factor, anti-cyclic-citrillinated antibody antibody, and HLA-B27 negative, but p-ANCA-and MPO antibody positive. CONCLUSIONS: Patients exposed to cocaine-levamisole may develop serious chronic sequelae including cicatrical cutaneous and facial deformities and an atypical seronegative, p-ANCA and MPO antibody-positive, HLA-B27-negative chronic deforming inflammatory arthritis.

HLA-B27 spondyloarthritis and spotted fever rickettsiosis: case-based review.

Rickettsia rickettsii, a tick borne disease, is the pathogen responsible for inducing Rocky Mountain Spotted Fever (RMSF), an illness that can progress to fulminant multiorgan failure and death. We present a case where R. rickettsii, acquired on a camping trip, precipitated a flare of peripheral arthritis and episcleritis in an HLA-B27 positive patient. Although Yersinia, Salmonella, Mycobacteria, Chlamydia, Shigella, Campylobacter, and Brucella have been previously associated with HLA-B27 spondyloarthritis, this unusual case demonstrates that obligate intracellular rickettsial organisms, and specifically, R. rickettsii, can also induce flares of HLA-B27 spondyloarthritis. Rickettsial infections in general can rapidly become fatal in both healthy and immunosuppressed patients, and thus, prompt diagnosis and therapy are required.

Characteristics of Behcet's Disease in the American Southwest.

OBJECTIVE: The goal of this study was to determine the characteristics of Behçet's disease (BD) in the American Southwest. MATERIAL AND METHODS: This was a cross-sectional study of BD patients clinically encountered during a 2-year period. All subjects fulfilled the International Study Group criteria (ISG) or International Criteria for Behcet's Disease (ICBD). Age, gender, clinical characteristics, substance use, and HLA-B51 status were determined. RESULTS: 63 patients (female: male ratio: 4.7:1) fulfilled ISG criteria and 76 the ICBD criteria (estimated prevalence of 8.9-10.6 per 100,000). 84.1% (53/63) were initially diagnosed with non-BD primary diagnoses including inflammatory arthritis (15.9%), fibromyalgia (7.9%), vasculitis (7.9%), or systemic lupus erythematosus (7.9%). Common BD manifestations were oral aphthous ulcers (100%), acneiform lesions (69.8%), genital aphthous ulcers (61.9%), papulopustular lesions (52.4%), pseudofolliculitis (42.9%), inflammatory arthritis (41.3%), anterior uveitis (23.8%), posterior uveitis (15.9%), pathergy (15.9%), deep vein thrombosis (14.3%), non-ocular vasculitis (11.1%), erythema nodosum (7.9%), arterial thrombosis (6.3%), and retinal vasculitis (1.6%). BD ethnic proportions were 49.2% Hispanic American (HA), 31.7% European-American (EA), 14.3% Native American (NA), and 1.7% Silk Road. HLA-B51 was present more in NA (89.0%, p = 0.02) and HA (74.2%, p = 0.02) compared to EA (42.1%). Therapy of BD was conventional, except for the frequent use of hydroxychloroquine. CONCLUSIONS: BD is common in the American Southwest with a prevalence of 8.9-10.6 cases per 100,000. BD patients are commonly initially diagnosed with alternative primary conditions. Hydroxychloroquine may be an effective alternative therapy for BD. This is one of the first reports of BD in HA and NA populations.

Extractable synovial fluid in inflammatory and non-inflammatory arthritis of the knee.

INTRODUCTION/OBJECTIVES: We hypothesized that mechanical compression of the knee in rheumatoid arthritis (RA) would mobilize occult extractable fluid and improve arthrocentesis success. METHODS: Sixty-seven consecutive knees with RA and 186 knees with OA and were included. Conventional arthrocentesis was performed and success and volume (milliliters) determined; the needle was left intraarticularly, and mechanical compression was applied with an elastomeric knee brace. Arthrocentesis was then resumed until fluid return ceased. Fluid was characterized as to volume and cell counts. RESULTS: In the RA, knee mechanical compression decreased failed diagnostic arthrocentesis from 56.7% (38/67) to 26.9% (18/67) (- 47.4%, p = 0.003) and increased absolute arthrocentesis yield from 4.7 ± 10.3 ml to 9.8 ± 9.8 ml (108% increase, 95% CI - 8.5 < - 5.1 < - 1.7 p = 0.0038). Total extractable fluid yield was 96% greater in RA (9.8 ± 9.8 ml) than OA (5.0 ± 9.4 ml, p = 0.0008), and occult extractable fluid was 77% greater in RA than OA (RA 5.3 ± 8.7 ml, OA 3.0 ± 5.5 ml, p = 0.046). Large effusions versus small effusions in RA demonstrated increased neutrophils in synovial fluid (p = 0.04) but no difference in radiologic arthritis grade (p = 0.87). In contrast, large effusions versus small effusions in OA demonstrated no difference in neutrophils in synovial fluid (p = 0.87) but significant different radiologic arthritis grade (p = 0.04). CONCLUSION: Mechanical compression improves the success of diagnostic and therapeutic knee arthrocentesis in both RA and OA. Large effusions in RA are associated with increased neutrophil counts but not arthritis grade; in contrast, large effusions in OA are associated with more severe arthritis grades but not increased neutrophil counts. Key points• Mechanical compression of the painful knee improves arthrocentesis success and fluid yield in both rheumatoid arthritis and osteoarthritis.• The painful rheumatoid knee contains approximately 100% more fluid than the osteoarthritic knee.• Large effusions in the osteoarthritic knee are characterized by higher grades of mechanical destruction but not increased neutrophil counts.• In contrast, large effusions in the rheumatoid knee are characterized by higher synovial fluid neutrophil counts but not the grade of mechanical destruction, indicating different mechanisms of effusion formation in rheumatoid arthritis versus osteoarthritis.

Kaposi Sarcoma as a Cutaneous Vasculitis Mimic: Diagnosis and Treatment.

Painful, palpable purpura usually indicate underlying vasculitis. We report a case of systemic vasculitis treated with immunosuppression that developed painful, vasculitis-like purpuric lesions that progressed rapidly to fulminant Kaposi sarcoma (KS). These purpuric, tumorous lesions resolved completely following the suspension of immunosuppression; however, without immunosuppression, the underlying autoimmunity recurred. This case highlights the potential for early KS to present as a vasculitis mimic or pseudovasculitis that clinicians should keep in mind when purpuric, vasculitis-like lesions develop in an immunosuppressed patient with vasculitis. It is important to recognize these pseudovasculitis lesions as KS rather than recurrent vasculitis so that immunosuppression can be withdrawn.

Can Diagnostic and Therapeutic Arthrocentesis Be Successfully Performed in the Flexed Knee?

BACKGROUND/OBJECTIVE: The objective of this study was to determine whether the extended or flexed knee positioning was superior for arthrocentesis and whether the flexed knee positioning could be improved by mechanical compression. METHODS: Fifty-five clinically effusive knees underwent arthrocentesis in a quality improvement intervention: 20 consecutive knees in the extended knee position using the superolateral approach, followed by 35 consecutive knees in the flexed knee position with and without an external compression brace placed on the suprapatellar bursa. Arthrocentesis success and fluid yield in milliliters were measured. RESULTS: Fluid yield for the extended knee was greater (191% greater) than the flexed knee (extended knee, 16.9 ± 15.7 mL; flexed knee, 5.8 ± 6.3 mL; P < 0.007). Successful diagnostic arthrocentesis (≥2 mL) was 95% (19/20) in the extended knee and 77% (27/35) in the flexed knee (P = 0.08). After mechanical compression was applied to the suprapatellar bursa and patellofemoral joint of the flexed knee, fluid yields were essentially identical (extended knee, 16.9 ± 15.7 mL; flexed knee, 16.7 ± 11.3 mL; P = 0.73), as were successful diagnostic arthrocentesis (≥2 mL) (extended knee 95% vs. flexed knee 100%, P = 0.12). CONCLUSIONS: The extended knee superolateral approach is superior to the flexed knee for conventional arthrocentesis; however, the extended knee positioning and flexed knee positioning have identical arthrocentesis success when mechanical compression is applied to the superior knee. This new flexed knee technique for arthrocentesis is a useful alternative for patients who are in wheelchairs, have flexion contractures, cannot be supine, or cannot otherwise extend their knee.

Outcomes and cost-effectiveness of ultrasound-guided injection of the trochanteric bursa.

We hypothesized that ultrasound (US) guidance improves outcomes of corticosteroid injection of trochanteric bursitis. 40 patients with greater trochanteric pain syndrome defined by pain to palpation over the trochanteric bursa were randomized to injection with 5 ml of 1% lidocaine and 80 mg of methylprednisolone using (1) conventional anatomic landmark palpation guidance or (2) US guidance. Procedural pain (Visual Analogue Pain Scale), pain at outcome (2 weeks and 6 months), therapeutic duration, time-to-next intervention, and costs were determined. There were no complications in either group. Ultrasonography demonstrated that at least a 2-in (50.8 mm) needle was required to consistently reach the trochanteric bursa. Pain scores were similar at 2 weeks: US: 1.3 ± 1.9 cm; landmark: 2.2 ± 2.5 cm, 95% CI of difference: - 0.7 < 0.9 < 2.5, p = 0.14. At 6 months, US was superior: US: 3.9 ± 2.0 cm; landmark: 5.5 ± 2.6 cm, 95% CI of difference: 0.8 < 1.6 < 2.4, p = 0.036. However, therapeutic duration (US 4.7 ± 1.4 months; landmark 4.1 ± 2.9 months, 95% CI of difference - 2.2 < - 0.6 < 1.0, p = 0.48), and time-to-next intervention (US 8.7 ± 2.9 months; landmark 8.3 ± 3.8 months, 95% CI of difference - 2.8 < - 0.4 < 2.0, p = 0.62) were similar. Costs/patient/year was 43% greater with US (US $297 ± 99, landmark $207 ± 95; p = 0.017). US-guided and anatomic landmark injection of the trochanteric bursa have similar 2-week and 6-month outcomes; however, US guidance is considerably more expensive and less cost-effective. Anatomic landmark-guided injection remains the method of choice, but should be routinely performed using a sufficiently long needle [at least a 2 in (50.8 mm)]. US guidance should be reserved for extreme obesity or injection failure.

Tumoral Calcinosis of the Neck in a Patient with Systemic Sclerosis.

Tumoral calcinosis (TC) is rare in patients with systemic sclerosis but is associated with morbidity. Paraspinal TC may cause severe pain and potentially devastating neurological deficits. Surgical decompression by removing the TC masses and applying surgical techniques to support the spine have provided substantial relief of the symptoms in the majority of cases. However, death has occurred in the immediate postoperative period and can even occur after several months. Current indications for surgery include intractable neck pain and, most importantly, the development of neurological deficits. We present a patient with systemic sclerosis and symptomatic paraspinal TC in the neck treated conservatively for two years. This case report illustrates conditions permitting the sustained conservative treatment of paraspinal TC in systemic sclerosis patients.

Outcomes and cost-effectiveness of carpal tunnel injections using sonographic needle guidance.

This randomized controlled study addressed whether sonographic needle guidance affected the outcomes of corticosteroid injection for symptomatic carpal tunnel syndrome. Seventy-seven symptomatic carpal tunnels were randomized to injection by either (1) conventional anatomic landmark palpation-guided injection or (2) sonographic image-guided injection, each using a two-step technique where 3 ml of 1% lidocaine was first injected to hydrodissect and hydrodisplace critical intra-carpal tunnel structures followed by injection with 80 mg of triamcinolone acetonide (2 ml). Baseline pain, procedural pain, pain at outcome (2 weeks and 6 months), responders, therapeutic duration, total cost, and cost per responder were determined. There were no complications in either treatment group. Relative to conventional anatomic landmark palpation-guided methods, sonographic guidance for injection of the carpal tunnel resulted in 77.1% reduction in injection pain (p<0.01), a 63.3% reduction in pain scores at outcome (p<0.014), 93.5% increase in the responder rate (p<0.001), 84.6% reduction in the non-responder rate (p<0.001), a 71.0% increase in therapeutic duration (p<0.001), and a 59.3% ($150) reduction in cost/responder/year for a hospital outpatient (p<0.001). However, despite improved outcomes, cost per patient per year was significantly increased for an outpatient in a physician's office and was neutral for a hospital outpatient. Sonographic needle guidance significantly improves the performance and clinical outcomes of injection of the carpal tunnel and is cost-effective for a hospital-based practice, but based on current reimbursements, it significantly increases overall costs for medical care delivered in a non-hospital-based physician practice.

New device technologies for subcutaneous fat biopsy.

PURPOSE: Subcutaneous fat biopsy is useful for the evaluation of amyloidosis, environmental contaminants, lipid metabolism, genetic studies and diabetes research. The present study examined new technologies for fat biopsy. METHODS: Subcutaneous fat biopsy in 10 high-risk individuals was randomized to (i) a 10 ml reciprocating procedure device (RPD) mechanical syringe or (ii) a 60 ml vacuum syringe. Outcome measures included pain by the 10 cm Visual Analogue Pain Scale (VAS), adequacy of biopsied tissue, complications and diagnosis. The operator's ability to control syringes was quantitatively measured by the linear displacement method. RESULTS: Both syringes permitted facile aspiration of subcutaneous fat with adequate sample without complications. The mechanical and the vacuum syringes enhanced control of the needle compared to conventional syringes, reducing unintended forward penetration by 75% (3.6 ± 0.5 mm) and 87% (12.0 ± 1.4 mm), respectively (p < 0.0001). Free adipose cells were obtained in abundance as well as columnar biopsies containing intact blood vessels and connective tissue septa permitting precise microhistological examination. One case of primary AL amyloidosis (κ light chain disease) was diagnosed in each group. CONCLUSIONS: Subcutaneous fat biopsy by needle aspiration can be facilely achieved with new aspiration syringe technologies with improved needle control and enhanced patient safety.