Tophi Research Articles

From Patents to Progress: Unraveling Gout's Journey Through Clinical Trials and Advancements.

Gout, an inflammatory arthritis form, is renowned for its historical association with affluence. This review delves into its pathophysiology, exploring hyperuricemia, urate crystal formation, and the ensuing inflammatory response. The epidemiology of gout is examined, focusing on its rising prevalence and impact on public health. In this study, progress in gout management is discussed, involving pharmacological interventions, dietary changes, and emerging therapies. Genetic predisposition and triggers like alcohol, temperature, and diet are highlighted in this study. Prevention strategies, including serum urate-lowering therapy and lifestyle modifications, aim to reduce recurrent flares and complications. The inflammatory response in acute gout attacks is elucidated, involving immune cells, cytokines, and the NLRP3 inflammasome. Chronic gout manifestations, such as gouty tophus formation, are explored for their destructive impact on surrounding tissues. Recent advancements in gout treatment, including nanotherapies and novel compounds, are discussed, along with promising urate-lowering drugs. Cutting-edge research on zinc ferrite nanoparticles, dimethyl fumarate, and myricetin/nobiletin hybrids addresses oxidative stress and inflammation in gout. Additionally, the potential therapeutic role of methanolic leaf extract of Euphorbia milii and tip-loaded CLC-Soluplus® MAPs is explored as natural and transdermal alternatives for gout management. The review also covers the development status of new urate-lowering drugs, providing insights into promising candidates and their mechanisms. Patents on gout and recent diagnostic advancements using techniques like laser confocal micro Raman spectrometer, FTIR, and THz-TDS offer a more accurate approach for gout stone analysis, enabling early detection and targeted treatment.

Rare manifestation of gout: Gouty tophi in unusual locations

Rare manifestation of gout: Gouty tophi in unusual locations

Atypical gouty tophus masquerading as a foreign body granuloma

Subcutaneous nodular lesions in a patient with significantly elevated inflammatory markers always raise the possibility of infectious diagnoses such as atypical infection, pyogenic abscess, mycobacterial infection, and malignancy. Definitive diagnosis requires tissue biopsy and histopathologic examination. The atypical presentation of a foreign body granuloma with concurrent intraoperative findings supports the diagnosis of gouty arthritis.We report a case of a 67-year-old man who presented with an inflammatory nodular lesion on the left elbow that was initially suspected to have an infectious cause. Histopathologic examination of the nodular tissue later revealed that the patient had a foreign body granuloma due to urate crystal deposition. The atypical appearance of the gouty arthritis, the low serum urate level, the negative crystal identification in the synovial fluid, and the markedly elevated inflammatory markers, which did not respond to the previous antibiotic and steroid therapy, raised the suspicion of atypical infection in this case.

Correlations of characteristics with tissue involvement in knee gouty arthritis: Magnetic resonance imaging analysis

ObjectiveThis study investigates the MRI features of knee gouty arthritis (KGA), examines its relationship with the extent of tissue involvement, and assesses whether risk factors can predict KGA. Materials and methodsPatients diagnosed with KGA underwent MRI examinations, and two independent observers retrospectively analyzed data from 44 patients (49 knees). These patients were divided into mild and severe groups based on tissue involvement observed during arthroscopy. MRI features were summarized, and the intraclass correlation coefficient evaluated interobserver reproducibility. Single-factor analysis compared clinical indicators and MRI features between groups, while Cramer's V coefficient assessed correlations. Multivariate logistic regression identified predictors of tissue involvement extent, and a ROC curve evaluated diagnostic performance. ResultsAmong 49 knees, 18 had mild and 31 had severe tissue involvement. Key MRI features included ligament sketch-like changes, meniscal urate deposition, irregularly serrated cartilage changes, low-signal signs within joint effusion, synovial proliferation, Hoffa's fat pad synovitis, gouty tophi, bone erosion, and bone marrow edema. The interobserver reliability of the MRI features was good. Significant differences (P < 0.05) were observed between the groups for anterior cruciate ligament (ACL) sketch-like changes, Hoffa's fat pad synovitis, and gouty tophi. ACL sketch-like changes (r = 0.309), Hoffa's fat pad synovitis (r = 0.309), and gouty tophi (r = 0.408) were positively correlated with the extent of tissue involvement (P < 0.05). ACL sketch-like changes (OR = 9.019, 95 % CI: 1.364–61.880), Hoffa's fat pad synovitis (OR = 6.472, 95 % CI: 1.041–40.229), and gouty tophi (OR = 5.972, 95 % CI: 1.218–29.276) were identified as independent predictors of tissue involvement extent (P < 0.05). The area under the ROC curve was 0.862, with a sensitivity of 67.70 %, specificity of 94.40 %, and accuracy of 79.14 %. ConclusionThis comprehensive analysis of MRI features identifies ligament sketch-like changes, meniscal urate deposition, and low-signal signs within joint effusion as characteristic MRI manifestations of KGA. Irregular cartilage changes are valuable for differential diagnosis in young and middle-aged patients. ACL sketch-like changes, Hoffa's fat pad synovitis, and gouty tophi correlate with tissue involvement severity and are critical in predicting and assessing the extent of tissue involvement in KGA.

Giant Cell Tumor within the Tibialis Anterior Tendon: A Case Report

Giant cell tumors of tendon sheath (GCT-TS) also characterized as giant cell tumors of low malignant potential (GCT-TSLMP) are extremely rare entities found most frequently in the extremities. It appears as an enlarging painless mass and has a synovial origin. GCT-TS is approximately 1.6% of all soft tissue tumors.1 The GCT-TS of the tibialis anterior tendon is very rare, and recurrence has not been reported in the literature. The authors present a rare case of a 71-year-old male with a GCT-TS within the Anterior Tibialis tendon. The soft tissue mass is characterized by a mix of giant cell reaction &amp; gouty tophus occurring within the Tibialis Anterior Tendon

Primary Gouty Tophi Involving the Eyelid.

A 51-year-old male with no known history of gout was referred by his optometrist for bilateral lower eyelid cysts near the puncta. The lesions were not painful but were cosmetically concerning and excision was desired. Utilizing local anesthesia, the lesions were excised and sent to pathology for review. Pathology noted lesions to be "gouty tophus." Given that our patient had no history of gout, this is the first case report of gouty tophus on the eyelid being the initial manifestation of gout.

No Wound Healing Complications or Recurrences Were Seen and a High Level of Satisfaction Was Reported in Patients Who Underwent Endoscopic Olecranon Bursectomy for Recalcitrant Olecranon Bursitis

To determine the outcomes of endoscopic olecranon bursectomy for the treatment of recalcitrant olecranon bursitis in one surgeon's practice. A retrospective analysis was conducted on all patients who underwent an endoscopic olecranon bursectomy for the treatment of recalcitrant olecranon bursitis between January 2018 and May 2021 at one surgeon's practice. Demographic variables as well as causes for olecranon bursitis such as aseptic, septic, and gouty tophi were recorded. In addition, any complications such as infection, recurrence, wound failure, or hospitalizations were documented, with wound dehiscence, recurrence of bursitis, and return to the operating room being the primary outcome measures. During the final phone encounter before finalizing this project, patients were queried to obtain the patient-reported form of the American Shoulder and Elbow Surgeons Elbow Questionnaire, quick Disabilities of the Arm Shoulder and Hand score, and the Single Assessment Numeric Evaluation score. Our study included 28 patients (23 male and 5 female) with an average age of 68 years (ranging from 33-86 years), all of whom had follow-up. The average follow-up was 24.7 months (range 3-42 months). There were 15 cases (54%) of aseptic bursitis, 13 cases (46%) of septic bursitis, and 7 cases (25%) that contained gouty tophi (5 aseptic and 2 septic). Of the 28 patients, 4 experienced complications. These all occurred within 3 months of surgery. One necessitated hospitalization and intravenous antibiotics, 2 were minor infections treated with oral antibiotics, and one was swelling treated successfully with in-office aspiration. Overall, 24 (86%) patients reported no issues at all related to the surgery. There were no instances of recurrence, wound failure, or secondary operations. Of the 20 (71.4%) patients who were reached for patient-reported form of the American Shoulder and Elbow Surgeons Elbow Questionnaire, quick Disabilities of the Arm Shoulder and Hand score, and Single Assessment Numeric Evaluation scores, all 20 patients reported no residual pain or difficulties with daily tasks. Average satisfaction with the procedure was 9.9 of 10 and, on average, patients reported that their elbow functionality was 96% with 100% representing completely normal. In this population, patients who underwent endoscopic olecranon bursectomy experienced no recurrences or wound-healing complications necessitating return to the operating room. In addition, patients reported high function and satisfaction after the procedure. Level IV, therapeutic case series.

Gout-Induced Cervical Deformity and Progressive Myelopathy Mimicking Infection Requiring Cervical Reconstruction

IntroductionThis study describes a rare case where gout, a condition primarily associated with joint inflammation, initially manifested as a progressive cervical kyphotic deformity, mimicking infection and causing myelopathy. The patient, a previously healthy 56-year-old female, presented with severe jaw pain and a temporomandibular joint (TMJ) abscess, alongside two months of worsening balance and arm/hand tingling. Extensive clinical and radiographic assessments revealed a severe cervical kyphotic deformity with bony erosion at multiple vertebral levels, raising suspicion of an infectious cause of compressive myelopathy. MethodsThe patient underwent an urgent staged surgical intervention involving multilevel cervical decompression and fusion, coupled with cervical deformity correction. Post-surgery, she received antibiotics for seven days, during which pathological analysis unveiled collections of macrophages reacting to urate crystal deposition in a pattern consistent with gouty tophus. This unexpected diagnosis marked a novel case of undiagnosed gout-induced severe cervical deformity presenting with myelopathic symptoms and successfully managed through cervical spine deformity correction. ConclusionThis report underscores the significance of considering gout as a potential cause when encountering unusual spinal pathologies, especially in cases where gout-related symptoms are atypical. The presented 540-degree surgical approach effectively addressed both the cervical deformity and gout-induced myelopathic symptoms. To the best of our knowledge, this study represents the first documented instance of a patient with undiagnosed gout-induced severe cervical deformity successfully treated through cervical spine deformity correction, emphasizing the importance of vigilance and innovative management approaches in such rare clinical scenarios. As of the two-year follow-up, the patient exhibited significant symptom improvement and overall well-being.

Lumbosacral Paravertebral Tophaceous Gout on an Adolescent Mimicking Malignant Neoplasm in 18 F-FDG PET/CT.

Contrast-enhanced MRI was performed on a 17-year-old adolescent boy with chronic lumbar and lower-limb pain, which had worsened over the past 3 days. It revealed a suspicious malignant mass adjacent to right appendage of L5-S1 vertebrae, with mixed signals and heterogeneous and obvious enhancement. 18 F-FDG PET/CT was subsequently performed for staging. It showed an FDG-avid mass with mixed density in right psoas major muscle, involving adjacent appendage of L5-S1 vertebrae. Histopathological examination confirmed the mass to be gouty tophus, characterized by nodular homogeneous pink amorphous deposits around the cartilage tissue, surrounded by histiocytes and multinucleated giant cells.

Nasal Gouty Tophus

A 48-year-old, non-hypertensive, non diabetic man with uncontrolled gouty arthritis presented with a four-day swollen nasal mass. He was assessed to have a nasal abscess at the emergency room and was admitted for urgent management. Paranasal computed tomography (CT) scans showed a heterogeneously enhancing focus with areas of hypodensities in the nasal apex and dorsum extending into the right ala measuring 1.5 x 2.8 x 3.4 cm. with associated erosion of the cartilaginous part of the anterior nasal septum, soft tissue swelling and skin thickening in the nasal dorsum, nasal tip and right zygomatic region that was suspected to relate to an aggressive etiology. Tissue correlation was therefore recommended, and he underwent endoscopic-guided incision and drainage with biopsy and debridement of the nasal mass. The specimen submitted consisted of red to white, irregular, soft tissue fragments with an aggregate measurement of 1.5 x 1.5 x 0.5 cm. Microsections showed deposits of amorphous white to pink material with surrounding fibrosis and acute and chronic inflammatory cell infiltrates and foreign body giant cells. (Figures 1 and 2) Also seen in the background were fragments of sclerotic bone and bacterial colonies. These findings were consistent with gouty tophus with acute and chronic inflammation and bacterial colonization. The culture and sensitivity test of the nasal discharge showed growth of Enterobacter aerogenes (currently named Klebsiella aerogenes) which was identified by an automated mass spectrometry microbial identification system (VITEK® MS). Work-up also included uric acid levels which were within the reference interval at that time (6.57 mg/dL).

High-resolution ultrasound and MRI in the evaluation of the forefoot and midfoot.

Radiography is the appropriate initial imaging modality to assess for midfoot and forefoot pathology before turning to advanced imaging techniques. While most lesions of the mid- and forefoot can be diagnosed clinically, the exact nature and severity of the pathology is often unclear. This review addresses the use of the ultrasound, as well as the added value of magnetic resonance imaging, in diagnosing conditions of the midfoot and forefoot. Ultrasound allows a dynamic assessment as well as enabling imaging-guided interventions for diagnostic and therapeutic purposes. Practical tips for optimal examination of this area with ultrasound and magnetic resonance imaging are provided. Metatarsal stress fracture, Chopart's injury, Lisfranc injury, as well as the 1st metatarsophalangeal joint injury and lesser metatarsophalangeal plantar plate injury are injuries unique to the mid- and forefoot. The imaging anatomy of the 1st and lesser metatarsophalangeal joints is reviewed, as such knowledge is key to correctly assessing injury of these joints. Characteristic imaging features of masses commonly encountered in the mid- and forefoot, such as ganglion cyst, Morton neuroma, gouty tophus, plantar fibroma, foreign body granuloma, and leiomyoma are reviewed. The use of ultrasound and magnetic resonance imaging in assessing degenerative and inflammatory joint disorders, and in particular rheumatoid arthritis, of the mid- and forefoot region is also reviewed. In summary, when necessary, most lesions of the mid-and forefoot can be adequately assessed with ultrasound, supplemented on occasion with radiographs, computed tomography, or magnetic resonance imaging.

Surgical Management of Tophaceous Gout in the Upper Limb

Gouty tophi are a clinical manifestation of hyperuricemia in advanced stages. They can produce pain, functional limitation, and severe deformities. Patients with severe symptoms require short-term symptomatic solutions that standard medical management is not able to provide. The objective of this study was to present the results obtained with the surgical management of tophaceous gout in the upper limb, as well as present a detailed characterization of the disease in the upper limb. Databases of the hand surgery service of a quaternary care hospital were reviewed to identify patients aged >18 years old undergoing tophi resection in the upper limbs between 2014 and 2020. Medical history records were reviewed retrospectively, and the relevant data were extracted to establish demographic profile, clinical presentation, anatomic distribution, postoperative outcomes, and additional procedures required. The most frequent symptom was pain (83%), followed by limited range of motion (56%), deformity (50%), and daily living/occupational activity limitation (28%). The main indications for surgical management were the presence of deformity, pain, and/or limited range of motion. The most frequently affected anatomic sites were the metacarpophalangeal joints, followed by the elbows, proximal interphalangeal joints, and proximal phalanges. The postoperative complication rate was 28%. The most common complications were operative site infections and wound dehiscence. Decreased pain was associated with surgical resection. Additional procedures, such as extensor tenorrhaphy and local flaps, were required in 47.2% of patients. Surgical resection of tophi can decrease pain. Although surgery is associated with ahigh rate of complications, most are minor. Therapeutic IV.

GOUTY TOPHUS MASQUERADING AS DIABETIC FOOT DIAGNOSED ON FNAC : A CASE REPORT

Nodular swelling around joints can be a dilemma in diagnosis for clinicians as well as pathologists. Any periarticular swelling has a wide range of differential diagnosis. We here present a case of 52 yr old male with uncontrolled diabetes presenting with nodular swelling at right lateral malleolus misdiagnosed as diabetic foot .FNAC revealed presence of Mono Sodium Urate crystals. In further investigation high serum uric levels were detected and diagnosis of gouty tophus was made. We here highlight the role of FNAC as a diagnostic tool for Gouty Tophus.

Changes in Tophus Composition During Urate-Lowering Therapy: A Dual-Energy Computed Tomography Study.

The gouty tophus is an organized structure composed of monosodium urate (MSU) crystals and chronic inflammatory soft tissue. This dual-energy computed tomography (DECT) study aimed to determine whether the composition of the tophus changes during urate-lowering therapy. Serial DECT scans from 32 people with gout were obtained over 2 years of allopurinol therapy, dose-escalated to serum urate of <0.36 mmoles/liter. Up to 5 index tophi were selected for each patient, with 103 separate tophi included in the analysis. Using manual outlining methods of conventional CT and DECT scans, the same index tophi were serially measured for total tophus volume and urate volume. For each tophus, the soft tissue volume was then calculated by subtracting the urate volume from the total tophus volume. The mean ± SD serum urate reduced from 0.43 ± 0.03 mmoles/liter at baseline to 0.31 ± 0.02 mmoles/liter at year 2. The mean ± SD total tophus volume reduced over the 2-year period from 5.17 ± 5.55 cm3 to 2.61 ± 2.73 cm3 (P < 0.0001). Greater reductions in tophus urate volumes than tophus soft tissue volumes were observed; the tophus urate volume decreased by 70.6%, and tophus soft tissue volume decreased by 37.8% (P < 0.0001). The mean tophus urate:soft tissue ratio reduced from 0.15 at baseline to 0.05 at year 2 (P < 0.001). The composition of the tophus is dynamic and changes during urate-lowering therapy for gout management. The soft tissue component of the tophus is slower to respond and may persist without measurable MSU crystal deposition.

Gouty Tophus at Unusual Site Presenting As Soft Tissue Mass Diagnosed By Fine Needle Aspiration Cytology with Review of Literature

Fine needle aspiration cytology (FNAC) is becoming a popular clinical practice in diagnosis of soft tissue nodules. We present a case of 58 years old male with bilateral, painless sub cutaneous nodules near the elbow without any clinical and radiological features of arthritis. Serum uric acid levels were found to be marginally high. Fine needle aspiration revealed negatively birefringent needle shaped crystals consistent with monosodium urate crystals in amorphous granular debris. Diagnosis of gouty tophi was given. FNAC is a valuable diagnostic tool for the diagnosis of periarticular nodules and pathologists should be aware of cytological features of gouty tophi, particularly in cases of unusual presentation.

Hyperuricaemia, gout and related adverse events associated with antihypertensive drugs: A real-world analysis using the FDA adverse event reporting system.

Background: The role of antihypertensive drugs in inducing hyperuricaemia and gout has been a long-term concern in clinical practice. However, clinical studies regarding this issue are limited in number and have yielded inconsistent results. We comprehensively evaluated the association between various antihypertensive drugs and the occurrences of hyperuricaemia, gout and related adverse events (AEs) using the FDA Adverse Event Reporting System (FAERS), aiming to guide the selection of antihypertensive drugs with a goal of minimizing the risk of hyperuricaemia, gout and related AEs. Methods: We used OpenVigil 2.1 to query the FAERS database. Hyperuricaemia, gout and related AEs were defined by 5 Preferred Terms: hyperuricaemia, gout, gouty arthritis, gouty tophus and urate nephropathy. Disproportionality analysis was performed, and a positive signal indicated an association between AEs and antihypertensive drugs. Results: The numbers of antihypertensive drugs with positive signals for hyperuricaemia, gout, gouty arthritis, gouty tophus and urate nephropathy were 46, 66, 27, 8 and 6, respectively. These drugs included diuretics, antihypertensive drugs with central action, α blockers, β blockers, α and β blockers, calcium channel blockers, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, renin inhibitors, vasodilators, and compound preparations. Furthermore, 42 antihypertensive drugs had positive signal for more than one AEs. Conclusion: Our study suggests that some potassium-sparing diuretics, calcium channel blockers and losartan may be associated with increased risk of hyperuricaemia, gout or related AEs, which is inconsistent with most previous studies. Moreover, Our study also suggests that some antihypertensive drugs with central action, α and β blockers, renin inhibitors and vasodilators may be associated with increased risk of hyperuricaemia, gout or related AEs, which has not been reported in previous studies. These findings complement real-world evidence on the potential risks of hyperuricaemia, gout and related AEs associated with antihypertensive drugs.

Cloacally Located Kidney Prolapsing in a Kingsnake Species (Lampropeltis spp.)

An 8 1/2 year old, female, Kingsnake (Lampropeltis spp.) presented for apparent constipation of 1 month duration. The physical exam revealed moderate constipation based on coelomic palpation. Radiographs confirmed probable follicular tissue in the mid-coelomic region and more radiodense fecal material within the distal colon. The snake was given an enema and, in the process, prolapsed a firm mass on a pedunculated stalk. The stalk was immediately ligated and transected due to mild hemorrhaging. Histopathology confirmed that the mass consisted of kidney tissue affected with a bacterial nephritis and contained granulomas and gouty tophi. Necropsy of the animal confirmed that the left kidney was missing within the coelomic cavity and had migrated to within the cloacal lumen. Additionally, the animal had severe folliculostasis and a bacterial cloacitis with foreign material (hair shafts) imbedded within the colonic body wall.

Clinical features of gout in adult patients with type Ia glycogen storage disease: a single-centre retrospective study and a review of literature

BackgroundThis study aimed to explore the clinical features of gout in adult patients with glycogen storage disease type Ia (GSD Ia).MethodsNinety-five adult patients with GSD Ia admitted to Peking Union Medical College Hospital were retrospectively analysed. A clinical diagnosis of GSD Ia was confirmed in all patients through gene sequencing. All patients had hyperuricaemia; 31 patients complicated with gout were enrolled, and 64 adult GSD Ia patients with asymptomatic hyperuricaemia were selected as a control group during the same period. Clinical characteristics were analysed and compared between the two groups.ResultsThirty-one of the 95 patients had complications of gout (median age, 25 years; 11 (35.5%) females). All 31 patients had hepatomegaly, abnormal liver function, fasting hypoglycaemia, hyperuricaemia, hyperlipaemia, and hyperlacticaemia. A protuberant abdomen, growth retardation, recurrent epistaxis, and diarrhoea were the most common clinical manifestations. Among these 31 patients, 10 patients (32.3%) had gout as the presenting manifestation and were diagnosed with GSD Ia at a median time of 5 years (range, 1–14) after the first gout flare. The median age of gout onset was 18 years (range, 10–29). Fifteen of the 31 GSD Ia-related gout patients were complicated with gouty tophi, which has an average incidence time of 2 years after the first gouty flare. The mean value of the maximum serum uric acid (SUA) was 800.5 μmol/L (range, 468–1068). The incidence of gout in adult GSD Ia patients was significantly associated with the initial age of regular treatment with raw corn starch, the proportion of urate-lowering therapy initiated during the asymptomatic hyperuricaemic stage, maximum SUA level, and mean cholesterol level.ConclusionsDetermination of GSD Ia should be performed for young-onset gout patients with an early occurrence of gouty tophi, especially in patients with hepatomegaly, recurrent hypoglycaemia, or growth retardation. Early detection and long-term regulatory management of hyperuricaemia, in addition to early raw corn starch and lifestyle intervention, should be emphasized for GSD Ia patients in order to maintain good metabolic control.Trial registrationRetrospectively registered.

Unusual Finding of Gouty Tophus in Adult Male with Acute Locked Knee: A Rare Case Report

Gout is an inflammatory disease commonly characterized by tophus deposits containing uric acid crystals in the intraarticular joints. An acute locked joint due to gouty tophus formation is a rare finding. This case describes a 36-year-old man with sudden pain and locking in the knee joint. Physical examination, plain radiography, and serum uric acid examination showed unremarkable results. Further investigation with diagnostic arthroscopy confirmed tophaceous gout as the sole cause of an acutely locked knee. The patient exhibited satisfactory clinical results following surgical intervention under arthroscopy and the administration of urate-lowering agents. This case highlights the probability of tophus deposition as the cause of an acute locked knee, despite unremarkable initial presentation. The awareness regarding this case should be raised, especially on emphasizing arthroscopy as a cost-effective diagnostic and therapeutic modality in patient management.

Gouty Tophus of a Flexor Tendon at the Level of the Wrist.

Gout (lat. diathesis uraemica) is a metabolic and inflammatory disease associated with increased synthesis or reduced excretion of the uric acid. The aetiology and pathogenesis involve genetic predispositions (SLC2A9 gene polymorphism), environmental factors (effect of alcohol, an excess of purines, fructose, use of diuretics) and coexisting diseases (metabolic syndrome, diabetes, renal failure). The disease is six times fold more frequent in men than in women [1], [2]. Crystallisation of monosodium urate crystals in the synovial fluid and their deposition in joints and periarticular tissues results in damage of the cartilage, joint capsule, ligaments and tendons. In approximately 50–60 % of patients, formation of gouty nodules usually occurs around the joints. Deposition of monosodium urate in the tendons is not uncommon, but it usually has a form of infiltration (incrustation) of the tendon by urate crystals rather than a regular nodule with well-defined capsule.