Clinical image. Tophaceous gout of the lumbar spine: MR findings

The anatomical pathology of gout: a systematic literature review

Background

The aim of this systematic literature review was to comprehensively describe the anatomical pathology of tissues affected by gout.

Methods

We searched PubMed, The Cochrane Library, Excerpta Medica Database (EMBASE), and Web of Science Core Collection for all English language articles published before March 2018. Articles were included if they described the microscopic or macroscopic appearances of gout in human tissue.

Results

Four hundred and seventeen articles met inclusion criteria and were included in the review. Articles describing the anatomical pathology of gout in musculoskeletal structures, including bone, tendon and ligaments, synovium and cartilage, were most common. Articles describing skin and kidney pathology in gout were also common, with pathology in other sites such as visceral organs less common. At all sites, monosodium urate crystal deposition was reported, and the tophus was also described within many different tissues. During a gout flare, diffuse acute neutrophilic synovial inflammation was evident. The tophus was described as an organised chronic giant cell granulomatous structure consisting of monosodium urate crystals, innate and adaptive immune cells, and fibrovascular tissue.

Conclusions

Consistent with the clinical presentation of gout, most studies describing the anatomical pathology of gout report involvement of musculoskeletal structures, with monosodium urate crystal deposition and tophus the most common lesions described. This review details the anatomical pathology features of gout at affected sites.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2519-y) contains supplementary material, which is available to authorized users.

Rogue one: a story of tophaceous gout in the spine

A 26-year-old man with history of extensive tophaceous gout presented to the referring facility with decreased bilateral lower extremity sensation and motor function that began acutely 1 week prior to admission and had progressed to urinary incontinence. The patient was admitted to the intensive care unit due to concern for sepsis secondary to epidural abscess. The patient was started on empiric vancomycin and cefepime. Neurosurgery did not recommend acute neurosurgical intervention given the lack of a compressive lesion. Aspiration of the paraspinal collection by interventional radiology subsequently showed crystals consistent with tophaceous gout. Given the high initial suspicion for gout and results of the paraspinal aspiration, the patient was started on prolonged steroid taper as well as allopurinol and colchicine. The patient eventually had partial neurological recovery with discharge to an inpatient rehabilitation facility for further physical therapy rehabilitation.

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.

Gout in the spine

Axial gout can affect all segments of the spine. It is manifested as back pain, as pain associated with neurological symptoms, and as neurological impairment without pain in 17.9%, 75.8% and 4.2% of cases, respectively. These manifestations were the first presentation of gout in many patients. Although x-rays as well as computed tomography and especially magnetic resonance scans can be very suggestive, histopathological, cytological and crystal analyses are the diagnostic gold standard. In most cases involving neurological manifestations, the patient underwent surgery, leading to satisfactory results. There are, however, some reports of full recovery following the usual clinical treatment for gout, suggesting that such treatment may be the initial option for those subjects with a history of gout and radiological findings of axial involvement.

First metatarsophalangeal joint arthrodesis for the treatment of tophaceous gouty arthritis

In tophaceous gouty arthritis, surgeons face the choice between preservation of the involved joint and arthrodesis after tophi excision. Magnetic resonance imaging (MRI) can allow evaluation of the distribution of tophaceous deposits, which can be difficult to visualize on radiography. The goal of this study was to evaluate the characteristic MRI features of tophaceous lesions and to compare the clinical outcomes of arthrodesis after tophi excision with those of simple tophi excision. The authors reviewed 16 feet in 15 consecutive patients diagnosed with tophaceous gouty arthritis of the first metatarsophalangeal (MTP) joint who underwent surgery. Nine feet (group A) were treated with simple tophi excision, whereas the other 7 (group B) underwent first MTP joint arthrodesis after tophi excision. For clinical evaluation, the visual analog scale (VAS) for pain, American Orthopaedic Foot and Ankle Society (AOFAS) score, Tegner activity scale, and patient satisfaction assessments were used. Magnetic resonance imaging was performed to evaluate the characteristics of tophaceous deposits in the first MTP joint. Mean VAS and AOFAS scores and patient satisfaction significantly differed between the 2 groups at final follow-up (P=.007, .005, and .002, respectively). In group A, progression of arthritis of the first MTP joint was observed in 6 of 9 cases at final follow-up. The tophaceous lesions of these 6 cases were found to be located intra-articularly on MRI. Arthrodesis after tophi excision should be considered for treating tophaceous gouty arthritis of the first MTP joint when tophi are located intra-articularly and loss of cartilage involved is greater than 50% of the entire joint.

Lumbar spinal stenosis induced by rare chronic tophaceous gout in a 29-year-old man

Spinal gout is rare in patients younger than 45 years, occurring most commonly between ages 45 and 80 years. This article describes a 29-year-old man with a history of gout initially observed more than 20 years previously who presented with lower back pain and left lower limb weakness. Computed tomography and magnetic resonance imaging revealed severely damaged facet joints and laminae surrounding L4-S1, and materials with a granular, yellow, cheese-like appearance were observed under direct vision. Postoperative histological examination confirmed spinal gout. Complete posterior decompression was performed concurrently with interbody fusion at L4-L5 and L5-S1. Seventeen-month follow-up revealed good recovery.The mechanism by which urate crystals form preferentially in the spine as opposed to more common soft tissue sites is not well understood. Most reported spinal gout cases were located at L4-S1, which were believed to be the segments with high stresses. These cases occurred in older patients with degenerative spinal diseases and had trauma as indicators. The current authors presume that gout is more likely to exist in the mobile regions with high pressure, such as L4-S1, even in individuals with an initially healthy spine, especially with a long period of abnormal renal dysfunction. Although it is often overlooked in young patients, this condition may be more common than the literature suggests due to the high potential for misdiagnosis in relatively young patients.

Spinal gout: case report and review of the literature

Spinal involvement is considered to be a rare complication of gout. We report a case of a 48-year-old woman with chronic tophaceous gout, recently desensitized to allopurinol, who presented with an L4 radiculopathy. A magnetic resonance image (MRI) of the lumbosacral spine revealed an extradural process at L4 level. Three months before this episode, for unrelated reasons, the patient had an MRI of her entire spine, which was normal. Laminectomy was performed revealing a large gouty tophus. The fact that a large gouty tophus formed over this short a period of time causing neurologic symptoms highlights the importance of aggressive medical management of patients with longstanding tophaceous gout with urate-lowering agents. Spinal extradural gout could lead to neurologic deficits necessitating emergent surgery for decompression, exposing the patient to further risk. Every effort should be made to lower the serum uric acid level by maximizing the pharmacologic regimen and, if necessary, desensitizing the patient, like in our case, if there is a history of allergy to allopurinol.

Gout in the Axial Skeleton

Objective.

Gout typically affects the peripheral joints of the appendicular skeleton and rarely involves the axial joints. The literature on axial gout is limited to case reports and case series. This preliminary study was conducted to identify the frequency and characteristics of axial gout.

Methods.

Six hundred thirty medical records with ICD codes 274.0, 274.82, and 274.9 for peripheral gout were reviewed. Ninety-two patients had clinical or crystal-proven gout, of which 64 had prior computed tomography (CT) images of the spine performed for various medical reasons. These CT images were reviewed for features of axial gout, which include vertebral erosions mainly at the discovertebral junction and the facet joints, deposits of tophi, and erosions in the vertebral body, epidural space, ligamentum flavum and pars interarticularis.

Results.

Nine of the 64 patients had radiographic changes suggestive of axial gout. Lumbar vertebrae were most commonly involved, with facet joint erosions being the most common finding. Isolated involvement of the sacroiliac joints was seen in 2 patients. Axial gout had been diagnosed clinically in only one patient.

Conclusion.

Radiologic changes of axial gout were more common than recognized clinically, with a frequency of 14%. Since not all patients had CT images, it is possible that the frequency of axial involvement was even greater. A prospective study is needed to further define this process.

MR imaging of the spinal bone marrow

Adequate interpretation of a cervical, thoracic, or lumbar spine MR imaging examination includes a careful evaluation of the bone marrow. Detecting an abnormality in bone marrow may cause a diagnostic dilemma because the marrow in the spine can vary in appearance according to the patient's age, and can be affected by infectious, inflammatory, metabolic, and neoplastic processes. Its appearance can be affected as well by underlying degenerative disc disease, trauma, and numerous iatrogenic therapies, including vertebroplasty, radiation therapy, and medications. In addition to conventional MR imaging sequences, newer imaging techniques, such as diffusion weighting and opposedphase sequences, are being studied to help increase the diagnostic accuracy of spine and bone marrow evaluation and to help differentiate benign from malignant and infectious processes.

Crystal arthropathy of the lumbar spine: a report of 4 cases

Gout or pseudogout, caused by deposition of crystals, rarely affects the spine. We report 4 cases with gout or pseudogout in the lumbar spine. Two had cauda equina syndrome and another 2 had spinal stenosis. To avoid unnecessary surgery, this should be considered in the differential diagnosis when treating patients with histories of gout or pseudogout for spinal problems.

Spinal gout in a renal transplant patient: a case report and literature review

BACKGROUND

Gout in the axial spine is rare. We present a case report on a renal transplant patient who developed fever and acute back pain at the L5 through S1 level secondary to sodium urate deposits. We review the literature on this rare disease and propose a management algorithm based on a resulting analysis.

CASE DESCRIPTION

A 37-year-old man with a history of gout and a renal transplant for IgA nephropathy presented with acute back pain and fever without evidence of neurological deficits. Magnetic resonance imaging revealed a uniformly contrast-enhancing infiltrative process involving the right pedicle, lamina, and inferior facet of the L5 vertebra. Computed tomography-guided needle biopsy revealed a friable white tissue consistent with sodium urate crystals. Conservative treatment with steroids and narcotics was used with good symptomatic relief.

CONCLUSION

Although few cases of gout involving the spine have been reported, its prevalence is likely grossly underestimated. Most patients have a history of gout and have elevated levels of serum urate level on presentation. The disease most commonly involves the lumbar spine. Patients usually have neurological deficits on presentation, and surgical decompression produces favorable outcomes. However, conservative medical management is appropriate for those with back pain only. Aggressive control of hyperuricemia is essential regardless of the method of treatment.

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.

MR Imaging: Arthropathies and Infectious Conditions of the Elbow, Wrist, and Hand

The superior soft tissue contrast and multiplanar capability of MR imaging has contributed to earlier diagnosis and implementation of effective treatment for a variety of arthropathies and infectious conditions of the elbow, wrist, and hand. Because of overlapping clinical signs and symptoms, MR imaging plays an important role in delineating the features and staging of each of these conditions. This article discusses the seropositive and seronegative inflammatory arthropathies, with emphasis on early detection and surveillance, as well as gout, synovial osteochondromatosis, pigmented villonodular synovitis, tenosynovitis, and de Quervain's tenosynovitis. Certain noninflammatory arthritides and infectious conditions are also reviewed.

Crystal arthropathy of the lumbar spine: a series of six cases and a review of the literature

There have been very few reports in the literature of gout and pseudogout of the spine. We describe six patients who presented with acute sciatica attributable to spinal stenosis with cyst formation in the facet joints. Cytopathological studies confirmed the diagnosis of crystal arthropathy in each case. Specific formation of a synovial cyst was identified pre-operatively by MRI in five patients. In the sixth, the diagnosis was made incidentally during decompressive surgery. Surgical decompression alone was undertaken in four patients. In one with an associated degenerative spondylolisthesis, an additional intertransverse fusion was performed. Another patient had previously undergone a spinal fusion adjacent to the involved spinal segment, and spinal stabilisation was undertaken as well as a decompression. In addition to standard histological examination material was sent for examination under polarised light which revealed deposition of urate or calcium pyrophosphate dihydrate crystals in all cases. It is not possible to diagnose gout and pseudogout of the spine by standard examination of a fixed specimen. However, examining dry specimens under polarised light suggests that crystal arthropathy is a significant aetiological factor in the development of symptomatic spinal stenosis associated with cyst formation in a facet joint.

Surgical versus pharmacologic treatment of intraspinal gout

A controversy between pharmacologic and surgical treatment of intraspinal gout exists in the literature. If gout is diagnosed timely, pharmacologic therapy may avert the need of surgery. The lack of readily available synovial fluid makes the diagnosis particularly difficult. The purpose of this study was to evaluate the clinical pictures and magnetic resonance imaging features in rapid differentiations of intraspinal gout. I retrospectively evaluated lumbar intraspinal tophaceous gout without the classic radiographic punched-out lesions. Four patients (average age, 65 years) had a history of hyperuricemia with multiple tophaceous deposits in the joints or visceral organs or both. The common presentations were low back pain with or without inflammatory reaction (fever, elevated C-reactive protein level, and mild leukocytosis). The patients also presented with intermittent claudication or radiculopathy of variable duration or both. The gouty tophi yielded homogeneous and hypointense masses on T1- and T2-weighted images, with multiple hypointense speckles. The masses were located in bilateral lumbar facet joints in all patients, with additional midline extension along the ligamentum flavum in three. All patients had uneventful outcomes after surgical decompression and pharmacologic treatment. Rapid deposition of tophi may aggravate nerve compression. If neurologic deficits are found, surgical decompression can provide a satisfactory outcome.

LEVEL OF EVIDENCE

Therapeutic study, Level IV. See the Guidelines for Authors for a complete description of levels of evidence.

MR imaging: arthropathies and infectious conditions of the elbow, wrist, and hand

The superior soft tissue contrast and multiplanar capability of MR imaging has contributed to earlier diagnosis and implementation of effective treatment for a variety of arthropathies and infectious conditions of the elbow, wrist, and hand. Because of overlapping clinical signs and symptoms, MR imaging plays an important role in delineating the features and staging of each of these conditions. This article discusses the seropositive and seronegative inflammatory arthropathies, with emphasis on early detection and surveillance, as well as gout, synovial osteochondromatosis, pigmented villonodular synovitis, tenosynovitis, and de Quervain's tenosynovitis. Certain noninflammatory arthritides and infectious conditions are also reviewed.

Tophaceous gout of the spine: MR imaging features

AIM

To define the magnetic resonance (MR) imaging features of tophaceous gout of the spine.

MATERIALS AND METHODS

We present the MR imaging examinations of 4 patients with spinal tophaceous gout. Spin-echo T1-weighted and fast spin-echo T2-weighted images were obtained for all patients, and 2 patients had gadolinium-enhanced MR imaging studies. Corresponding computed tomography (CT) was performed in one patient. All images were evaluated for the characteristics of the gouty tophi.

RESULTS

The gouty tophi were located at the lower thoracic (n=1) and lumbar (n=3) levels. All tophi yielded homogeneous intermediate to low signal on T1-weighted images and variable signal intensity on T2-weighted images, comprising small foci of very low signal intensity on all sequences. Gadolinium-enhanced MR imaging studies revealed homogeneous enhancement or heterogeneous peripheral enhancement. Diffuse stippled calcifications were found in the tophi on CT images. Periarticular tophi with juxtaarticular bony erosions around facet joints occurred in 3 patients.

CONCLUSION

Spinal tophaceous gout should be considered in the differential diagnosis when periarticular deposits contain very low signal foci on all MR imaging sequences.

Tophaceous gout of the spine mimicking epidural infection: case report and review of the literature

OBJECTIVE AND IMPORTANCE

Tophaceous gout uncommonly affects the axial skeleton. The clinical presentations of gout of the spine range from back pain to quadriplegia. Gout that presents as back pain and fever may be difficult to distinguish from spinal infection. We present a case of a patient with tophaceous gout of the lumbar spine who was initially diagnosed with and treated for an epidural infection. The clinical and diagnostic features of tophaceous gout of the spine are reviewed.

CLINICAL PRESENTATION

A 70-year-old man presented with a 2-day history of fever and back pain. A physical examination revealed that he had flank tenderness and evidence of polyarthritis affecting the elbows, knees, and right first metatarsophalangeal joint. A magnetic resonance imaging scan of the patient's lumbar spine showed an extensive area of abnormal gadolinium enhancement of the paramedian posterior soft tissues from L3 to S1 with an area of focal enhancement extending into the right L4-L5 facet joint.

INTERVENTION

A laminectomy was performed at L4-L5, and a chalky white material in the facet joint was found eroding into the adjacent pars intra-articularis. Light and polarizing microscopy confirmed the presence of gouty tophus. No evidence of infection was found.

CONCLUSION

Gouty arthritis of the spine is rare. Thirty-seven previous cases have been reported. When the clinical presentation includes acute back pain and fever, differentiation of spinal gout from spinal infection may be difficult. The clinical suspicion of spinal gout may lead to the correct diagnosis by a less invasive approach than exploration and laminectomy.

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.

Destructive tophaceous calcium hydroxyapatite tumor of the infratemporal fossa. Case report and review of the literature

Tophaceous pseudogout is one of the rarest forms of crystal deposition disease, typically presenting as a destructive and invasive mass involving the temporomandibular joint or the infratemporal fossa region in the absence of any other articular manifestations. Previous cases have been assumed to be caused by calcium pyrophosphate dihydrate (CPPD) crystal deposition, based on finding weakly birefringent crystals in the involved tissues. The authors present the unique case of a 65-year-old woman with a destructive and invasive facial mass extending to the middle cranial fossa with microscopic and clinical features consistent with tophaceous pseudogout. High-resolution x-ray crystallographic powder diffraction and Fourier transformed infrared spectroscopy subsequently revealed that the crystals were composed of calcium hydroxyapatite without CPPD. The patient was later found to have primary hyperparathyroidism and mild hypercalcemia. This case demonstrates that tissue deposits of calcium hydroxyapatite can cause a destructive and invasive mass containing weakly birefringent crystals and raises the question of whether previous cases attributed to tophaceous pseudogout resulting from CPPD actually were composed of birefringent calcium hydroxyapatite.