The gouty tophus: a review

Urate and osteoarthritis: Evidence for a reciprocal relationship

Hyperuricemia is a common condition, and in a subset of patients leads to gout, the most common inflammatory arthritis. Osteoarthritis is the most common form of arthritis overall, and gout and osteoarthritis frequently coexist in the same patient. However, the relationship between the two remains poorly defined. More particularly, the impact of osteoarthritis on the development of gout, and the impact of gout on the development of osteoarthritis, remain to be determined. Additionally, whether hyperuricemia mediates osteoarthritis in the absence of gout is uncertain. Here, we review the evidence linking gout and osteoarthritis, with a special focus on the role of hyperuricemia in the presence or absence of gout. Since disease modifying agents are currently available for hyperuricemia and gout but not for osteoarthritis, a contributory role for urate in the pathogenesis of osteoarthritis could have important clinical implications.

Impact of Dual-Energy CT Postprocessing Protocol for the Detection of Gouty Arthritis and Quantification of Tophi in Patients Presenting With Podagra: Comparison With Ultrasound

OBJECTIVE. The objective of our study was to compare ultrasound (US) tophus and monosodium urate (MSU) deposit detection and US tophus size in the metatarsophalangeal (MTP) 1 joint with dual-energy CT (DECT) using two DECT postprocessing protocols in patients presenting with podagra. SUBJECTS AND METHODS. Seventy-five consecutive patients with podagra (66 men and nine women; mean age, 65.6 years; age range, 33-88 years) and 75 control subjects with MTP 1 joint osteoarthritis (49 men and 26 women; mean age, 63.0 years; age range, 35-87 years) prospectively underwent US and DECT between 2016 and 2018 to assess the MTP 1 joint. Two Syngovia postprocessing DECT protocols with different minimum attenuation thresholds of 150 HU (DECT 150 protocol) versus 120 HU (DECT 120 protocol) and the same maximum attenuation threshold (500 HU) and constant kilovoltage setting of tubes A and B at 80 and 140 kVp were evaluated. Interobserver variability of the two DECT protocols was calculated and compared with that of US. RESULTS. The postprocessing DECT 150 protocol was positive for tophus detection in 55 of 75 patients (73.3%) with podagra, whereas the postprocessing DECT 120 protocol detected MSU deposits in all 75 patients (100%). Tophus size assessed using the DECT 120 protocol showed an improved correlation with tophus size detected on US (p < 0.01). Interobserver variability of DECT was improved when using the DECT 120 protocol (p < 0.01). CONCLUSION. The postprocessing DECT 120 protocol enables improved visualization of MSU deposits and provides more accurate information about tophus size that better correlates with tophus size on US compared with the standard postprocessing DECT 150 protocol.

The role of neutrophil extracellular traps in rheumatic diseases

Rheumatic diseases are a collection of disorders defined by the presence of inflammation and destruction of joints and internal organs. A common feature of these diseases is the presence of autoantibodies targeting molecules commonly expressed in neutrophils. These preformed mediators are released by neutrophils but not by other immune cells such as macrophages. Neutrophils, major players in the host innate immune response, initiate a cell death mechanism termed neutrophil extracellular trap (NET) formation as a way to ensnare pathogens. NETs are also a source of released self-molecules found in rheumatic diseases. Subsequently, research on the role of NETs in the onset, progression and resolution of inflammation in rheumatic diseases has intensified. This Review has two aims. First, it aims to highlight the mechanisms required for the generation of NETs, the research landscape of which is rapidly changing. Second, it aims to discuss the role of neutrophils and NETs in systemic lupus erythematosus, vasculitis (specifically anti-neutrophil cytoplasmic autoantibody-associated vasculitis), rheumatoid arthritis and gout. Our goal is to clarify the field of NET research in rheumatic diseases in the hope of improving the therapeutic approaches utilized for these diseases.

Clinical characteristics and risk factors of ulceration over tophi in patients with gout

OBJECTIVES

To describe clinical characteristics of ulceration over tophi in patients with gout and determine risk factors associated with ulceration.

METHODS

Patients presenting with tophi or ulceration(s) over tophi were prospectively recruited and their clinical characteristics were recorded. Comparison of clinical characteristics and risk factors for ulceration were analyzed between groups.

RESULTS

A total of 105 patients were enrolled. Thirty-three patients with ulcerations were older, with prolonged duration with gout and tophi, a higher rate of obesity, greater numbers of tophi, lower levels of glomerular filtration rate (GFR), and higher levels of serum creatinine, erythrocyte sedimentation rate and C-reactive protein. The mean duration of ulceration was 1.63 ± 2.32 months. The ulcerations were mainly located in the ankle (34.21%) and metatarsophalangeal joints (39.47%), with a mean size of 32.37 × 22.76 mm. The majority of ulcerations were categorized as stage I (42.4%) and stage II (51.5%). In univariate regression analysis, age, glucocorticoid overuse, gout duration, tophi duration, tophi number and GFR were associated with ulceration. In the multivariable model, significant differences were demonstrated in glucocorticoid overuse, tophi duration, tophi number.

CONCLUSIONS

Gout patients with ulceration(s) over tophi present several different aspects of clinical characteristics compared with those without ulceration. The ulcerations are most commonly seen in feet and they are mainly categorized as stages I and II. Glucocorticoid overuse, prolonged duration with tophi and greater numbers of tophi are risk factors for ulceration over tophi.

Painless gouty tophus in the nasal bridge: A case report and literature review

RATIONALE

A gouty tophus, arising from the deposition of monosodium urate crystals (MSU), rarely occurs in the nasal bridge. There have been only 7 documented cases of a gouty tophus in the nasal bridge from 1978 to 2018 in English-language literature.

PATIENT CONCERNS

A 65-year-old male had a chief complaint of a lump in the nasal bridge that was slowly growing for over 1 year.

DIAGNOSIS

MSU crystals were confirmed through ultrasonography (US) and pathological examinations.

INTERVENTIONS

A cosmetically less destructive method, ultrasound-guided fine needle aspiration cytology (FNAC) was used to approach the mass lesion of nasal bridge.

OUTCOMES

The diagnosis was confirmed as a gouty tophus without performing a nasal subdermal exploration.

LESSONS

This case report is the first use of US with FNAC to approach and diagnosed a gouty tophus in the nasal bridge.

Unusual presentation of gouty tophus in the liver with subsequent appearance in the same site of HCC: a correlate diagnosis? Case report

Background

Although gout is a common disease, the presence of gouty tophi outside joints is rare and in literature, there is to date only one report of hepatic tophaceous nodule. We would like to highlight here the difficult diagnostic workup in a patient with history of cancer and the presence of a tophus inside the liver. Moreover, we address the possible etiologic role of chronic inflammation related to tophi and liver cancer.

Case presentation

We present the case of a 72-year-old man with a localization of gouty tophus in the liver, who thereafter developed a hepatocellular carcinoma (HCC) in the same site. The patient was followed up after surgery for left renal cancer from 1992 to 2011, when a hepatic nodule was discovered for the first time. After a detailed evaluation, the nodule was classified as a urate tophus of the liver. However, further follow-up showed that the nodule increased in size and changed its characteristics, bringing to the diagnosis of HCC.

Conclusions

With the present case report, we would discuss the possible neoplastic degeneration of a gouty tophus and its etiologic role favouring cellular degeneration linked to chronic inflammation. We would also highlight the importance of histopathological evaluation of hepatic lesions in gouty patients at high risk of liver neoplasm, due to the difficulty in characterizing gouty tophi by imaging.

Differentiating the acute phase of gout from the intercritical phase with ultrasound and quantitative shear wave elastography

OBJECTIVES

To evaluate the value of ultrasound (US) in differentiating the acute phase of gout from the intercritical phase, particularly using shear wave elastography (SWE).

METHODS

57 gout patients were prospectively enrolled and divided into acute phase and intercritical phase groups. The patients underwent US and SWE examinations for the first metatarsophalangeal joints with the same protocol. Maximum synovial thickness was measured. US features were reviewed by two radiologists independently. The maximum (E_max) and mean (E_mean) elastic moduli of synovium were calculated. Diagnostic performances of US, SWE and combined US and SWE were evaluated.

RESULTS

US findings demonstrated that the colour Doppler flow signal grade in the acute phase was higher than that in the intercritical phase (p = 0.001), whereas no differences were found for B-mode US features between the two groups (all p > 0.05). For SWE, E_max and E_mean were significantly higher in the intercritical phase than in the acute phase (both p < 0.001). The areas under the receiver operating characteristic curve (AUROCs) were 0.494-0.553 for B-mode US, 0.735 for colour Doppler US (CDUS), 0.887 for E_max and 0.882 for E_mean. The combination of CDUS and SWE increased the AUROC, sensitivity and accuracy significantly in comparison with CDUS alone (all p < 0.001). However, the combined set did not show stronger diagnostic performance in comparison with SWE alone.

CONCLUSION

SWE increases the diagnostic performance in differentiating the acute phase of gout from the intercritical phase in comparison with conventional US.

KEY POINTS

• Colour Doppler flow signal grade is higher in acute phase of gout than in intercritical phase. • SWE demonstrates that synovium stiffness is higher in intercritical phase of gout than in acute phase. • SWE increases diagnostic performance in differentiating acute phase of gout from intercritical phase in comparison with conventional US.

Gout: An old disease in new perspective - A review

Gout is a picturesque presentation of uric acid disturbance. It is the most well understood and described type of arthritis. Its epidemiology is studied. New insights into the pathophysiology of hyperuricemia and gouty arthritis; acute and chronic allow for an even better understanding of the disease. The role of genetic predisposition is becoming more evident. The clinical picture of gout is divided into asymptomatic hyperuricemia, acute gouty arthritis, intercritical period, and chronic tophaceous gout. Diagnosis is based on laboratory and radiological features. The gold standard of diagnosis is identification of characteristic MSU crystals in the synovial fluid using polarized light microscopy. Imaging modalities include conventional radiography, ultrasonography, conventional CT, Dual-Energy CT, Magnetic Resonance Imaging, nuclear scintigraphy, and positron emission tomography. There is remarkable progress in the application of ultrasonography and Dual-Energy CT which is bound to influence the diagnosis, staging, follow-up, and clinical research in the field. Management of gout includes management of flares, chronic gout and prevention of flares, as well as management of comorbidities. Newer drugs in the pharmacological armamentarium are proving successful and supplement older ones. Other important points in its management include patient education, diet and life style changes, as well as cessation of hyperuricemic drugs.

Asymptomatic Papules and Subcutaneous Nodules as First Sign of Gout

The authors describe a case report characterised by asymptomatic papules and non-tender subcutaneous nodules as the isolated manifestations of gout.

Ultrasonography and dual-energy computed tomography provide different quantification of urate burden in gout: results from a cross-sectional study

Background

Ultrasonography (US) and dual-energy computed tomography (DECT) can assess urate burden in gout. The objective of this study was to compare the quantification of urate deposition provided by US to the one provided by DECT.

Methods

Patients with a diagnosis of gout were prospectively recruited to undergo quantification of urate deposition using US and DECT. US examination for tophi and the double contour (DC) sign was performed on the knees and feet and corresponding DECT scans provided volumes of tophi and of overall urate deposition. The primary endpoint was the intra-class correlation coefficient (ICC) of the volume of the index tophus measured by US and DECT and its 95% confidence interval (CI 95%).

Results

Of the 64 patients included, 34 presented with at least one tophus on US. DECT inter-reader agreement for urate deposition was perfect with an ICC of 1 (1–1) and good for the measurement of the index tophus with an ICC of 0.69 (0.47–0.83). The ICC for the measurement of the index tophus between the two techniques was poor with a value of 0.45 (0.1–0.71). The average ratio between the index tophi volume as assessed by DECT and US was 0.65. The number of DC-positive joints did not correlate with DECT volume of overall deposits (Spearman correlation coefficient of 0.23).

Conclusions

DECT measurements of tophi give smaller volumes to the same tophi measured with US, and US signs of urate deposition in joints do not correlate with overall DECT volumes of extra-articular deposition.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1381-2) contains supplementary material, which is available to authorized users.

Molecular Pathophysiology of Gout

Three contradictory clinical presentations of gout have puzzled clinicians and basic scientists for some time: first, the crescendo of sterile inflammation in acute gouty arthritis; second, its spontaneous resolution, despite monosodium urate (MSU) crystal persistence in the synovium; and third, immune anergy to MSU crystal masses observed in tophaceous or visceral gout. Here, we provide an update on the molecular pathophysiology of these gout manifestations, namely, how MSU crystals can trigger the auto-amplification loop of necroinflammation underlying the crescendo of acute gouty arthritis. We also discuss new findings, such as how aggregating neutrophil extracellular traps (NETs) might drive the resolution of arthritis and how these structures, together with granuloma formation, might support immune anergy, but yet promote tissue damage and remodeling during tophaceous gout.

Comparison of dual-energy CT, ultrasound and surface measurement for assessing tophus dissolution during rapid urate debulking

Tophaceous gout is painful and impairs quality of life. The optimal modality for assessing tophus resolution in response to urate-lowering treatment remains poorly defined. Using pegloticase as a model system for resolving tophi, we compared multiple imaging and physical diagnostic strategies for assessing tophus resolution. A 32-year-old subject with chronic refractory tophaceous gout was enrolled and received 6 months of pegloticase treatment. Measurements of tophi using vernier calipers (monthly), photographs and musculoskeletal ultrasound (MSK-US; every 3 months), and dual-energy CT (DECT) were compared. Pegloticase persistently lowered the patient's sUA to <0.5 mg/dl. After 6 months, caliper measurements revealed 73, 60, and 61% reductions of three index tophi, while MSK-US revealed 47, 65, and 48% reductions. In contrast, DECT revealed 100% resolution of monosodium urate deposition in all three index tophi, and resolution or improvement of all other tophi identified. On caliper and MSK-US measurement, index tophus size fluctuated, with some lesions enlarging before ultimately contracting. Correlation between assessment modalities during tophus resolution may be poor. DECT identifies urate deposits invisible to physical exam and reveals that some urate deposits completely resolve even as their physically/sonographically measurable lesions persist. Recognition of urate resorption during the urate-lowering process may be confounded by fluctuating lesion volumes during initial tophus breakdown. While DECT was superior for identifying total (including occult) urate deposition, and assessing volume of deposits, other modalities may permit better assessment of non-urate tophus components.

Images in clinical medicine: Tophi

Tophi (plural of tophus, Latin for “stone”) are stone-like deposits of monosodium urate in the soft tissues, synovial tissues, or in bones near the joints. They are pathognomonic for gout, the most common inflammatory arthritis in the United States, with an estimated lifetime prevalence of 4%. It is usually the end result of loss of the balance between uric acid production and excretion. It can be found anywhere in the body especially in areas of friction or trauma. It is usually painless and rarely to present as the initial manifestation of gout. It is diagnosed mainly clinically. Imaging is mainly used to assess the complication like bony erosions. The American College of Rheumatology (ACR) guidelines currently indicate that urate-lowering therapy should be initiated in patients with the presence of tophi visible on examination or imaging (ACR Evidence A). First-line therapy for urate lowering remains the xanthine oxidase inhibitor allopurinol. The ACR currently recommends colchicine, 0.6 mg (or 0.5 mg) once or twice daily, or low dose NSAIDs should be continued to reduce gout flare incidence for six months after resolution of the tophus. Daily prednisone ≤10 mg has been endorsed as an acceptable second-line prophylactic agent.

Abbreviations: ACR: American College of Rheumatology; NSAID: non-steroidal anti-inflammatory drug

An unusual location of gouty panniculitis: A case report

RATIONALE

Gouty panniculitis, characterised by the deposition of monosodium urate crystals in subcutaneous tissue, is a rare clinical manifestation of gout.

PATIENT CONCERNS

The case of a 67-year-old man is reported, who presented an erythematous nodule on the upper part of the right buttock suspicious for an abscess. This was in the context of chemotherapy for non-Hodgkin's lymphoma.

DIAGNOSES

Histopathologic examination demonstrated gouty panniculitis.

INTERVENTIONS

Because infection was suspected, an incision was performed. The lesion was found to be densely calcified and friable, without purulent discharge. Therefore, a surgical en-bloc resection was performed.

OUTCOMES

The wound healed slowly initially due to a combination of malnutrition, chemotherapy and infection. A wound infection with Enterococcus faecium was treated with antibiotic therapy (carbapenem for seven days) and local therapy. At 6-week follow up the wound showed good granulation tissue and was healing well by secondary intention. The patient was instructed to continue anti-hyperuricaemic treatment.

LESSONS SUBSECTIONS

In patients known to have long-standing hyperuricaemia and gout with nonspecific subcutaneous erythematous nodules, gouty panniculitis should be considered.

Neutrophil Extracellular Traps and Microcrystals

Neutrophil extracellular traps represent a fascinating mechanism by which PMNs entrap extracellular microbes. The primary purpose of this innate immune mechanism is thought to localize the infection at an early stage. Interestingly, the ability of different microcrystals to induce NET formation has been recently described. Microcrystals are insoluble crystals with a size of 1-100 micrometers that have different composition and shape. Microcrystals have it in common that they irritate phagocytes including PMNs and typically trigger an inflammatory response. This review is the first to summarize observations with regard to PMN activation and NET release induced by microcrystals. Gout-causing monosodium urate crystals, pseudogout-causing calcium pyrophosphate dehydrate crystals, cholesterol crystals associated with atherosclerosis, silicosis-causing silica crystals, and adjuvant alum crystals are discussed.

Population-specific association between ABCG2 variants and tophaceous disease in people with gout

Background

Tophi contribute to musculoskeletal disability, joint damage and poor health-related quality of life in people with gout. The aim of this study was to examine the role of SLC2A9 and ABCG2 variants in tophaceous disease in people with gout.

Methods

Participants (n = 1778) with gout fulfilling the 1977 American Rheumatism Association (ARA) classification criteria, who were recruited from primary and secondary care, attended a detailed study visit. The presence of palpable tophi was recorded. SLC2A9 rs11942223, ABCG2 rs2231142 and ABCG2 rs10011796 were genotyped. Data were analysed according to tophus status.

Results

Compared to participants without tophi, those with tophi were older, had longer disease duration and higher serum creatinine, and were more likely to be of Māori or Pacific (Polynesian) ancestry. SLC2A9 rs11942223 was not associated with tophi. However, the risk alleles for both ABCG2 single nucleotide polymorphisms (SNPs) were present more frequently in those with tophi (OR (95% CI) 1.24 (1.02–1.51) for rs2231142 and 1.33 (1.01–1.74) for rs10011796, p < 0.05 for both). The effect of rs2231142 was limited to participants of Māori or Pacific ancestry (OR 1.50 (1.14–1.99), p = 0.004), with a significant effect observed in those of Western Polynesian ancestry only (OR 1.71 (1.07–2.72), p = 0.017). The rs10011796 risk allele was strongly associated with tophi in the Western Polynesian group (OR 3.76 (1.61–8.77), p = 0.002), but not in the Eastern Polynesian group (OR 0.87 (0.52–1.46), p = 0.60) nor in the non-Polynesian group (OR 1.16 (0.81–1.66), p = 0.32). The ABCG2 associations persisted in the Western Polynesian group after adjusting for serum urate, creatinine, and disease duration, and when including both ABCG2 variants in the regression models.

Conclusions

Variation in ABCG2 function may play a role in the development of tophaceous disease in some populations with high prevalence of severe gout.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1254-8) contains supplementary material, which is available to authorized users.

Multiple Gouty Tophi with Bone Erosion and Destruction: A Report of an Early-onset Case in an Obese Patient

A 27 year-old severely obese man (BMI, 35.1) had hyperuricemia and multiple gouty tophi with bone erosion and destruction, resulting in gait disturbance for 6 years after the early onset of gout at 21 years of age. His hyperuricemia was associated with hyperinsulinemia in obesity and a genetic variant of the ABCG2 gene. In addition, multiple gouty tophi with bone erosion and destruction might have been caused by hypoadiponectinemia and the elevation of the patient' s pro-inflammatory cytokine (IL-1β) level with the accumulation of visceral fat. In this case, bone and Ga-67 scintigraphy were useful for detecting the location and magnitude of gouty tophi.

P2Y6 Receptor Antagonist MRS2578 Inhibits Neutrophil Activation and Aggregated Neutrophil Extracellular Trap Formation Induced by Gout-Associated Monosodium Urate Crystals

Human neutrophils (polymorphonuclear leukocytes [PMNs]) generate inflammatory responses within the joints of gout patients upon encountering monosodium urate (MSU) crystals. Neutrophil extracellular traps (NETs) are found abundantly in the synovial fluid of gout patients. The detailed mechanism of MSU crystal-induced NET formation remains unknown. Our goal was to shed light on possible roles of purinergic signaling and neutrophil migration in mediating NET formation induced by MSU crystals. Interaction of human neutrophils with MSU crystals was evaluated by high-throughput live imaging using confocal microscopy. We quantitated NET levels in gout synovial fluid supernatants and detected enzymatically active neutrophil primary granule enzymes, myeloperoxidase, and human neutrophil elastase. Suramin and PPADS, general P2Y receptor blockers, and MRS2578, an inhibitor of the purinergic P2Y6 receptor, blocked NET formation triggered by MSU crystals. AR-C25118925XX (P2Y2 antagonist) did not inhibit MSU crystal-stimulated NET release. Live imaging of PMNs showed that MRS2578 represses neutrophil migration and blocked characteristic formation of MSU crystal-NET aggregates called aggregated NETs. Interestingly, the store-operated calcium entry channel inhibitor (SK&F96365) also reduced MSU crystal-induced NET release. Our results indicate that the P2Y6/store-operated calcium entry/IL-8 axis is involved in MSU crystal-induced aggregated NET formation, but MRS2578 could have additional effects affecting PMN migration. The work presented in the present study could lead to a better understanding of gouty joint inflammation and help improve the treatment and care of gout patients.

Macrophage-derived IL-1β enhances monosodium urate crystal-triggered NET formation

OBJECTIVE AND DESIGN

Arthritic gout is caused by joint inflammation triggered by the damaging effects of monosodium uric acid (MSU) crystal accumulation in the synovial space. Neutrophils play a major role in mediating joint inflammation in gout. Along with neutrophils, other immune cells, such as macrophages, are present in inflamed joints and contribute to gout pathogenesis. Neutrophils form neutrophil extracellular traps (NETs) in response to MSU crystals. In the presence of MSU crystals, macrophages release IL-1β, a cytokine crucial to initiate gout pathogenesis and neutrophil recruitment. Our research investigated interactions between human macrophages and neutrophils in an in vitro model system and asked how macrophages affect NET formation stimulated by MSU crystals.

MATERIALS OR SUBJECTS

Human neutrophils and PBMCs were isolated from peripheral blood of healthy volunteers. PBMCs were differentiated into macrophages in vitro using human M-CSF.

TREATMENT

Human neutrophils were pretreated with macrophage-conditioned media, neutrophil-conditioned media, recombinant human IL-1β or anakinra prior to stimulation by MSU crystals.

METHOD

Interaction of neutrophils with MSU crystals was evaluated by live imaging using confocal microscopy. The presence of myeloperoxidase (MPO) and neutrophil elastase (NE) was measured by ELISA. NET formation was quantitated by Sytox Orange-based extracellular DNA release assay and NE-DNA ELISA. AggNET formation was assessed by macroscopic evaluation.

RESULTS

We found that crystal- and cell-free supernatants of macrophages stimulated with MSU crystals promote MSU crystal-stimulated NET formation in human neutrophils. This observation was confirmed by additional assays measuring the release of MPO, NE, and the enzymatic activity of NE. MSU crystal-induced NET formation remained unchanged when neutrophil supernatants were tested. IL-1β is a crucial cytokine orchestrating the onset of inflammation in gout and is known to be released in large amounts from macrophages following MSU crystal stimulation. We found that recombinant IL-1β strongly promoted MSU crystal-induced NET formation in human neutrophils. Interestingly, IL-1β alone did not induce any NET release. We also found that clinical grade anakinra, an IL-1 receptor blocker, strongly reduced the NETosis-enhancing effect of macrophage supernatants indicating that IL-1β is mainly responsible for this effect.

CONCLUSIONS

Macrophage-derived IL-1β enhances MSU crystal-induced NET release in neutrophils. We identified a new mechanism by which macrophages and IL-1β affect neutrophil functions, and could contribute to the inflammatory conditions present in gout. Our results also revealed a new anti-inflammatory mechanism of anakinra.

Nasal gouty tophus: Report a rare case presenting as a nasal hump with nasal obstruction

Dorsal nasal gouty tophus are rare occurrences with limited documentation. Here we report a male patient who has a history of poorly controlled gouty arthritis. He had nasal obstruction with an enlarging mass over his left nasal ridge for the past three years. Image studies revealed a nasal bone defect underneath the nasal lesion. The firm mass was excised and confirmed to be of gouty origin. The nasal bone defect was repaired with a titanium mesh plate to prevent nasal depression. He has fully recovered with no more nasal obstruction or recurrence of nasal tophus. The case report illustrates a common illness, gout, with a rare clinical manifestation leading to a common symptom, nasal obstruction. It demonstrates the importance of a detailed history, a thorough physical examination and most important of all, an extensive differential diagnosis in our clinical practice.

Gout in the Spine: Imaging, Diagnosis, and Outcomes

Gout is characterized by the deposition of monosodium urate crystals and by acute and chronic inflammation in response to crystals so deposited. Multiple case reports and series describe the deposition of monosodium urate in the spine as a rare manifestation of gout, but the actual prevalence of spinal involvement is unknown and likely to be higher than generally anticipated. Here we review the characteristics of 131 previously reported cases of spinal involvement in gout. We focus in particular on the use of imaging modalities and the extent to which they correlate with presenting symptoms and tissue diagnoses. The recent innovation of using dual-energy computerized tomography to identify urate crystal deposition holds promise for reducing the need for surgical intervention and for establishing a true prevalence rate for spinal gout.

Tophaceous Gout in an Anorectic Patient Visualized by Dual Energy Computed Tomography (DECT)

Patient: Female, 40

Final Diagnosis: Gout

Symptoms: Joint pain

Medication: —

Clinical Procedure: Dual energy Computed tomography

Specialty: Rheumatology