Isolated or dominant lesions of the patella in gout: a report of seven patients

A rare case of tophaceous gout manifesting as an osteolytic lesion of the acromioclavicular joint

An osteolytic lesion on imaging can be considered malignancy until proven otherwise. However, advanced stages of gout have presented with sclerotic rims and lytic lesions thought to be due to overexpression of osteoclasts. Patients have been found to demonstrate osteolytic lesions in patellar regions, which are common locations for gout to manifest; however, to our knowledge, no other cases of osteolytic gout in the acromioclavicular joint have been reported at this time. We report a rare case of a 56-year-old male who presented with acute-on-chronic left upper extremity pain and was found to have an osteolytic lesion of the shoulder on imaging. This lesion was later biopsied and found to be histologically consistent with gout. This case report aims to elucidate further understanding of the various ways that gout can present, to diagnose and treat these patients more effectively.

Pathologic Fracture of The Patella Secondary to a Gouty Tophus

Gout is a rare cause of patellar fracture, with few documented cases. We report a case of gout tophi in the patella, the severe transverse fracture resulting from minor trauma. The patient was managed by the same treatment principles used for patients with nonpathologic patella fractures. We preformed excising the mass, fixing the bone fragment and filling in bone defect with allograft bone. Union of the fracture was seen at three months follow-up. The patient has recovered completely and returned to his former work after 3 months postoperatively.

Recent developments in advanced imaging in gout

The plain radiographic features of gout are well known; however, the sensitivity of plain radiographs alone for the detection of signs of gout is poor in acute disease. Radiographic abnormalities do not manifest until late in the disease process, after significant joint and soft tissue damage has already occurred. The advent of dual-energy computed tomography (DECT) has enabled the non-invasive diagnosis and quantification of gout by accurately confirming the presence and extent of urate crystals in joints and soft tissues, without the need for painful and often unreliable soft tissue biopsy or joint aspiration. Specific ultrasound findings have been identified and may also be used to aid diagnosis. Both ultrasound and magnetic resonance imaging (MRI) may be used for the measurement of disease extent, monitoring of disease activity or treatment response, although MRI findings are nonspecific. In this article we summarize the imaging findings and diagnostic utility of plain radiographs, ultrasound, DECT, MRI and nuclear medicine studies in the assessment as well as the implications and utility these tools have for measuring disease burden and therapeutic response.

MR imaging assessment of arthritis of the knee

The magnetic resonance (MR) imaging presentations of arthritis of the knee are important for radiologists to recognize because these disorders are often clinically unsuspected. When they are known or clinically suspected, knowledge of imaging features allows for the confirmation and characterization of the extent of disease. This article reviews the fundamental MR imaging manifestations of rheumatologic disorders of the knee and their presentation in specific arthropathies.

Intraosseous talar pseudotumour: an unusual presentation of gout

We report a rare case of an intraosseous talar pseudotumour associated with hyperuricaemia in a previously asymptomatic patient, treated with curettage and bone autograft. Satisfactory function and pain relief was obtained at 6 months follow up with no evidence of recurrent disease.

Arthritis mimicking sports-related injuries

Arthritis, including inflammatory, crystal deposition, and synovial proliferative disorders, may mimic sports injury. The purpose of this article is to review the clinical and radiologic findings of arthropathies that can present in athletes and be confused with internal derangement.

Tophaceous gout of the patella: a report of two cases

Introduction. Tophaceous gout of the patella is rare and may masquerade as a tumour or tumour-like condition. Cases. We report two patients with gout involving the patella, one complicated by a pathological fracture and the other occurring in a bipartite patella in a young adult. Discussion. Typical imaging appearances and measurement of serum urate will usually confirm the diagnosis but, occasionally, the serum urate level may be normal in active gout and in such cases, a biopsy will be required. Conclusion. Gout of the patella may masquerade as a tumour or tumour-like condition and it is important to consider gout in the differential diagnosis.

The broad spectrum of urate crystal deposition: unusual presentations of gouty tophi

OBJECTIVES

Gout is typically described as an inflammatory arthropathy that affects the peripheral joints. Our aim was to describe atypical and rare clinical presentations of gouty tophi to help increase physician awareness and aid in patient care.

METHODS

The relevant English literature of unusual gout manifestations was searched using the keywords gout, toph*, monosodium urate, uric acid, unusual, and rare. Well-described case reports, case series, and review articles were evaluated and included, if relevant, in the literature review.

RESULTS

Review of the literature revealed many unusual manifestations of gouty tophi involving the head and neck, skin, viscera, bones, tendons, ligaments, nerves, and axial skeleton. Transplant recipients, women, and elderly people are particularly susceptible to developing tophi. Furthermore, gout can cause diagnostic dilemmas, as it can be a great mimicker of and can coexist with infection, malignancy, and other connective tissue diseases. Imaging modalities can help detect tophi in atypical locations.

CONCLUSIONS

Tophi can present in unexpected locations, even as the first sign of gout, and vigilance is required when unusual symptoms or signs occur in a patient with gout.

Tophaceous gout of the knee: revisiting MRI patterns in 30 patients

OBJECTIVE

To evaluate the locations and associated erosions of tophaceous gout in the knee and to reevaluate its characteristic magnetic resonance imaging features.

MATERIALS AND METHODS

We performed a retrospective review of the magnetic resonance (MR) images of the knees of 30 patients with histopathologically confirmed gouty tophi. Each tophaceous lesion was evaluated for location, morphology, signal intensity, and associated bone erosion or intraosseous involvement.

RESULTS

The tophaceous masses were commonly located on the medial aspect of the infrapatellar fat pad and anterior joint recess (n = 28, 87%), the space adjacent to the lateral rim of the lateral femoral condyle (n = 25, 78%), and the intercondylar fossae (n = 22, 69%). All tophaceous lesions showed similar signal characteristics (low-intermediate signal intensities on T1-weighted images, with heterogeneous signal intensities on T2-weighted images), and 3 morphologic patterns were observed: amorphous masses (n = 27), linear crystalline-like deposits (n = 6), and cystic lesions of the bursae around the knee (n = 3). Associated bone erosions occurred in the lateral rim of the lateral femoral condyle (n = 8), the roof of the intercondylar notch (n = 7), the tibial eminence (n = 5), and the medial and lateral rim of the tibial plateau (n = 3). Intraosseous tophi were seen in the tibial plateau (n = 3) and patella (n = 1).

CONCLUSION

Knowledge of the common locations and associated erosions of tophaceous gout and its characteristic MR appearance may facilitate its correct diagnosis with magnetic resonance imaging, particularly in patients with no clinical symptom or only an isolated lesion on MR images.

Cystic pseudotumours in both upper ankle joints in gouty arthritis

This case demonstrates a yet unreported clinical entity of bilateral tophaceous cystic lesions of the tibiotalar joints of an 37-year-old white male who presents with moderate painful swelling in both upper ankle joints for 2 years. Radiodiagnostic studies show cystic lesions in both upper ankle joints and the right talus considering neoplastic processes in the differential diagnosis. The incisional biopsy reveals chalk-like material of the intraosseous lesions which was pathognomonic for tophaceous gout. Antihyperuricemic medication led to a stagnation of growth of the lesions without a sign of osseous remodeling. However, due to limitation of discomfort, personal preferences and a lack of surgical options conservative treatment was maintained.

Tumour and tumour-like lesions of the patella--a multicentre experience

Fifty-nine cases of lesions presenting in the patella were identified after review of the databases of four European bone tumour registries. Of the 59 cases, 46% were non neoplastic, 39% were benign and 15% were malignant. The commonest benign neoplasm was giant cell tumour (GCT) (11 cases). Younger patients were more likely to have a benign neoplasm. Lesions in patients less than 40 years of age included giant cell tumour, chondroblastoma, aneurysmal bone cyst (ABC), osteomyelitis, osteoid osteoma and solitary bone cyst. In patients older than 40 years, the following were common lesions: intra-osseous gout, metastasis and intra-osseous ganglion. Expansion of the patella with thinning of cortex was seen more commonly in GCT and brown tumour in hyperparathyroidism. There was associated soft tissue extension in gout and malignant lesions.

Pseudotumor of gout in the patella of a kidney transplant recipient

BACKGROUND

A 33-year-old renal transplant recipient presented with painless swelling of the right knee. Physical examination revealed an impressive knee joint effusion with no signs of inflammation. The patient did not remember a recent trauma, but he mentioned a strain 3 years earlier; radiographic findings had been normal at that time. The patient had suffered from end-stage renal disease due to chronic glomerulonephritis and had previously undergone two transplantations. At presentation, his kidney function was stable under treatment with ciclosporin, azathioprine and steroids.

INVESTIGATIONS

Conventional radiography revealed a tumor at the superolateral pole of the right patella. Extensive soft tissue invasion and bone destruction was seen on MRI. A knee arthroscopy with biopsy, performed to aid diagnosis, showed extensive chondrocalcinosis macroscopically; histologically, gouty tophi were found.

DIAGNOSIS

Pseudotumor of gout in the patella.

MANAGEMENT

Uric-acid-lowering therapy with benzbromarone was started immediately after diagnosis. A local arthroscopic debridement of the right knee joint was performed 4 months later, and the patient remained asymptomatic for the next 3 years.

Characteristic appearance of large subcutaneous gouty tophi in magnetic resonance imaging

The development of multiple large tophi in patients with gout is rare. We report magnetic resonance (MR) and histological features of large subcutaneous tophi in a 32-year-old male patient with no known arthritis. His subcutaneous lesions were confused with a neoplastic process, evaluated by MR imaging, and surgically excised after biopsy. The honeycomb-like appearance on the gadolinium-enhanced images may reflect the characteristic multilobular structure of the tophi composed of avascular urate deposits and surrounding vascularized granulation tissue.

Superficial soft-tissue masses of the extremities

Superficial soft-tissue masses are among the most common indications for imaging of the extremities. A broad array of benign and malignant processes may be manifested in palpable cutaneous or subcutaneous masses or nodules. Most such lesions are treated with surgical excision, but some may be conservatively managed. The lesions can be differentiated according to their location in one or more skin layers (epidermis, dermis, and subcutis), their histologic composition, and the associated anatomic abnormality or disease process. Because the imaging characteristics of many benign soft-tissue lesions overlap with those of malignant ones, knowledge of the patient's clinical history (including any laboratory test results) and direct visual examination of the lesion often are important for differentiation. Histologic analysis may be necessary to achieve a definitive diagnosis.

The advanced imaging of gouty tophi

Gout is a metabolic disorder in which there is hyperuricemia caused by an increase in production or a decrease in excretion of uric acid. Long-lasting hyperuricemia causes the deposition of monosodium urate crystals in the joints and soft tissues, triggering gouty arthritis and, if not properly treated, the formation of gouty tophi. The diagnosis of gout is usually based on clinical presentation and laboratory examinations, long before any abnormality can be demonstrated with imaging. Radiography is the primary imaging modality used in the initial evaluation of gouty arthritis. Ultrasonography, CT, MRI, and nuclear medicine are seldom necessary. Occasionally a tophus has an unusual presentation and simulates neoplasm or infection prompting the utilization of cross-sectional imaging for further evaluation and surgical planning. Cross-sectional imaging is also used in areas that are difficult to visualize on radiographs such as spine, sacroiliac joints, and soft tissues.

Tophaceous gout in the bipartite patella with intra-osseous and intra-articular lesions: a case report

We report a case of a 34-year-old man who had an acute gouty attack with tophi around the accessory bone of the bipartite patella with intra-osseous lesions. As the symptoms did not respond to conservative treatments, the patient was treated surgically. Arthroscopy revealed urate crystals surrounded by inflammatory synovitis on the surface of the bipartite patella. Arthrotomy exposed the abundant crystals around the accessory bone and in the intra-osseous lesion. These findings made us speculate that some pre-existing inflammatory conditions around the accessory bone induced deposition of urate crystals, and the destruction of the barrier between the deposits and the joint led to an acute arthritis. Curettage of the tophi resulted in immediate improvement of knee function. There had been no recurrence of symptoms at the 2-year follow-up.

Nonseptic monoarthritis: imaging features with clinical and histopathologic correlation

Diagnosis of septic arthritis requires aspiration and analysis of joint fluid. However, nonseptic articular disorders are fairly common and represent a significant diagnostic and therapeutic challenge. Such disorders include gout, Milwaukee shoulder, rapidly destructive articular disease, amyloid arthropathy, hemophilic arthropathy, primary synovial osteochondromatosis, pigmented villonodular synovitis, neuropathic arthropathy, and foreign-body synovitis. The clinical signs of articular disease, which include pain, swelling, and limitation of motion, are often nonspecific and can overlap with those of osseous or extraarticular disorders. Many articular processes have characteristic radiologic appearances that allow definitive diagnosis. Radiography is an important part of the evaluation of patients with articular disease. However, magnetic resonance (MR) imaging is the method of choice for characterizing the various disorders and assessing the full extent of osseous, chondral, and soft-tissue involvement. MR imaging can exquisitely demonstrate joint effusions, synovial proliferation, articular cartilage abnormalities, subchondral bone, ligaments, muscles, and juxtaarticular soft tissues. Although a wide spectrum of noninfectious processes may involve the joints, careful analysis of the imaging findings and correlation of these findings with the patient's clinical history can suggest a more specific diagnosis in most cases. Awareness and understanding of the underlying histopathologic findings aids in interpretation of MR images.

Carpal tunnel syndrome caused by tophaceous gout: CT and MR imaging features in 20 patients

OBJECTIVE

The objective of this study is to describe the CT and MR imaging findings of gouty tophi in the wrist and present this entity as a cause of carpal tunnel syndrome.

MATERIALS AND METHODS

Retrospective review of the CT (n = 18) and MR imaging (n = 20) studies of the wrist in patients with a documented diagnosis of gout who presented with gout-related carpal tunnel syndrome was performed; images of 24 wrists were collected over a 5-year period. Patient population included 20 men, who ranged in age from 35 to 76 years. All images were reviewed by two musculoskeletal radiologists who reached a consensus opinion. Surgical correlation was available in 12 patients.

RESULTS

Tophi were found in the floor of the carpal tunnel (n = 18), carpal bones (n = 17), radiocarpal joint (n = 17), and extensor tendons or tendon sheaths (n = 16) of the wrist. All tophi showed similar signal characteristics (from low to intermediate signal intensity on T1-weighted images with heterogeneous signal intensity on T2-weighted images) with the exception of tophi in the floor of the carpal tunnel (low signal intensity on T2-weighted images). Varying degrees of calcification were noted on CT and MR imaging studies. Gadolinium-enhanced MR studies showed heterogeneous enhancement.

CONCLUSION

Gouty tophi should be entertained as a cause of carpal tunnel syndrome in the appropriate patient population. Familiarity with this entity and its imaging characteristics may prove helpful in diagnosis and preoperative planning.

Intraosseous gouty invasion of the talus

A 34-year-old man presents with a cystic lesion of the talus that has developed over the last 3 years and a history of a single first metatarsophalangeal attack of gout. Radiodiagnostic studies confirmed the cyst and an associated osteochondritic lesion but showed no evidence of avascular necrosis. At arthroscopy, chalk-like material was removed from the cyst, which was histologically compatible with tophaceous gout. The lesion was debrided, and the patient was then treated with antihyperuricemic medication; radiographic evidence of cyst resorption was seen after 9 months of treatment.

Gout as a source of sesamoid pain

Isolated gout of a great toe sesamoid has not been described previously. We present a case of gout of the medial sesamoid in a young athlete. Because a diagnosis is often elusive in patients with sesamoid pain, it is possible that other cases of gout of a hallucal sesamoid have gone unrecognized. Consideration of this diagnosis might lead to curative medical therapy precluding the need for surgical intervention.