Gout Affecting the Nail Unit: Report of Two Cases and Literature Review

Background

Gout is a depositional, inflammatory disorder that is rarely reported to affect the nail unit. Cases of gout involving the nail unit are likely under-recognized and therefore underreported. We present two cases of tophaceous gout affecting the nail unit and a literature review of the various presentations.

Summary

Five cases of gout were identified to affect the nail unit. In all cases, these presented as white hyperkeratotic papulonodules with associated nail dystrophy. Chalky discharge was seen in three of the five cases. Nine cases were identified to have demonstrated pseudocarcinomatous changes that histopathologically mimic squamous cell carcinoma (SCC). Literature review highlights a range of findings including subclinical deposits of uric acid in the nail, onychoschizia, onychorrhexis, and Beau's line.

Key Messages

Physicians should be aware of the subtle and nonspecific clinical findings of gout, which may be easily misconstrued for other pathological entities.

A unique presentation of acute tophaceous gout in the lumbar spine causing cauda equina syndrome

Gout is a common metabolic disease characterized by the deposition of monosodium urate (MSU) crystals and typically affects the peripheral joint, rarely involving the axial skeleton. We present a rare case of acute tophaceous gout in the lumbar spine causing cauda equina syndrome. A 60-year-old man with a history of gout and prior admissions for polyarticular gout flare presented with acute onset of bilateral lower limb numbness and weakness. He underwent surgical decompression with drainage of the epidural collection, with histology consistent with tophaceous gout. The patient made a full recovery postoperatively and was discharged uneventfully. Due to the high initial suspicion for gout, early spinal decompression surgery was performed, and the patient was started on medical therapy. Spinal tophaceous should be considered in the list of different diagnoses of spinal epidural masses especially in the context of a history of gouty arthritis.

Bilateral carpal tunnel syndrome and motor dysfunction caused by gout and type 2 diabetes: A case report

BACKGROUND

Carpal tunnel syndrome (CTS) has been associated with gout and type 2 diabetes mellitus (T2DM). However, due to insufficient clinical understanding of gout-related CTS and reliance on the diagnostic importance of elevated serum uric acid levels, such cases are prone to missed diagnosis, misdiagnosis, and delayed treatment. In addition, the effect of T2DM on gout - induced carpal tunnel syndrome has not been reported.

CASE SUMMARY

Herein, we present an unusual case of CTS and motor dysfunction caused by miliary tophaceous gout and T2DM. The patient presented to the hand and foot clinic with paresthesia of the fingers of both hands, especially at night. The patient was diagnosed with type 2 diabetes a month ago. Ultrasonography revealed bilateral transverse carpal ligament thickening with median nerve compression during hospitalization. The patient was successfully treated with carpal tunnel decompression and tendon release. The postoperative pathological examination revealed typical gout nodules. This case suggests that the presence of T2DM could accelerate tophi formation and worsen CTS symptoms, although no definitive proof in this regard has been described previously.

CONCLUSION

Tophi formation may most likely cause the co-occurrence of CTS and flexor dysfunction in gout and incipient diabetes patients.

Beyond Medical Treatment: Surgical Treatment of Gout

PURPOSE OF REVIEW

Medical treatment with urate-lowering therapy (ULT) is efficacious. A recent publication suggested that surgery in gout is more prevalent than previously reported. This revelation led us to review what is known about surgical treatment of gout.

RECENT FINDINGS

The Google Scholar database (January 1, 2014-January 1, 2020) found 104 publications with a total of 169 gout patients, with an average disease duration of 6.7 years. Most (68%) were not on ULT. The mean pre-operative serum urate levels were 9.19 mg/dL. One hundred thirteen patients underwent tophi excision, while in 33 patients, tophi were found during surgery. The majority of the surgeries were performed in Asia and Europe. Most patients were not taking ULT at the time of surgery, leading to hyperuricemia. This can result in tophi reformation post-surgery. The role of surgery should be a last-line treatment and until recently has only been demonstrated through case reports.

Tophaceous gout in thoracic spine mimicking meningioma: A case report and literature review

Background:

Gout is a common metabolic disorder of purine metabolism, causing arthritis in the distal joints of the appendicular skeleton. Spine involvement is rare, and very few cases of spinal gout have been reported. The authors present a rare case of axial gout with tophaceous deposits in the thoracic spinal canal resulting in cord compression and mimicking a meningioma.

Case Description:

A 33-year-old male presented with chronic mid back pain and a progressive paraparesis. The presumed diagnosis was meningioma based on MR imaging with/without contrast that showed a posterolateral, right-sided, and T10-T11 intradural extramedullary lesion. Notable, was hyperuricemia found on hematological studies. The patient underwent a decompressive laminectomy (T9-T11) for excision of the lesion, intraoperatively, an intraspinal, chalky, white mass firmly adherent to and compressing the dural sac was removed. The histopathology confirmed the diagnosis of a gouty tophus. Postoperatively, the patient’s pain resolved, and he regained the ability to walk.

Conclusion:

A gouty tophus should be included among the differential diagnostic considerations when patients with known hyperuricemia present with back pain, and paraparesis attributed to an MR documented compressive spinal lesion.

Chronic carpal tunnel syndrome caused by covert tophaceous gout: A case report

Carpal tunnel syndrome (CTS) is well recognized as the most common type of peripheral neuropathy. A rare cause of CTS is tophaceous gout. Tophi deposits can accumulate in various structures including the flexor tendons, tendon sheaths, the carpal tunnel floor, transverse carpal ligament, and even the median nerve, causing various symptoms such as pain, numbness, and weakness. Tophi forming in the carpal canal can compress the median nerve, leading to CTS. Here, we describe a 25-year-old male with a family history of tophaceous gout who presented with typical CTS symptoms. Although he had chronic numbness in his right hand, he failed to present with any obvious palpable masses on his forearm or hand. However, his family history, laboratory, clinical, and magnetic resonance imaging findings were consistent with tophi deposits. CTS symptoms were eased through surgical removal of tophi and decompression of the median nerve. No recurrences of gout and CTS symptoms were reported at a one-year follow-up. This case shows that CTS symptoms could be the initial manifestation of tophaceous gout. In patients with a family history of gout and with CTS symptoms, imaging examinations are critical for early diagnosis and selecting appropriate treatment. Surgical removal of “covert” tophi and decompression of the median nerve is an effective option for eliminating symptoms.

Tophaceous gout causing thoracic spinal cord compression: Case report and review of the literature

OBJECTIVE

To improve neurologists' awareness of spine gout by showing a rare case of tophaceous gout in thoracic spine and a summary of vertebral gout in order.

MATERIAL AND METHODS

We reported a case of a 36-year-old male with a 2-year-history of hyperuricemia. Neurological examination suggested that the strength of his lower limbs decreased. Bilateral Babinski's sign and ankle clonus were positive. He had no bladder or bowel dysfunction. Computed tomography of the thoracic spine showed occupied lesions at the T9, T10 levels which led to the spinal stenosis. Magnetic resonance imaging of the thoracic spine revealed epidural disease at T9, T10 levels. A resection of the occupying lesion in the thoracic spinal canal was performed, tophaceous gout was diagnosed by the pathological examination. We also provide a brief review of literature on 30 cases of spine tophaceous gout.

RESULT

Spinal tophaceous gout is rare, gout can involved in any spine level, but the probability of occurrence of thoracic spine is the least. Most patients had a history of hyperuricemia or peripheral tophus, the most common symptoms are back pain, when the pain stone compression spinal cord or nerve root, there will be the corresponding neurological symptoms or signs.

CONCLUSIONS

The spinal gout should be considered when a patient has chronic or acute back pain and/or neurological symptoms, with mass on sides of the vertebras on MRI, especially when the patient has a history of hyperuricemia, the pathology examination can confirm the diagnosis.

[Tophaceous gout of the lumbar spine in a patient without systemic gout or normouricaemia]

Gout is a common metabolic disorder typically diagnosed in peripheral joints. Tophaceous deposits in the lumbar spine is a very rare condition with very few cases reported in the literature. We present a case of tophaceous gout that originated in the lumbar spine in a patient with normal uric acid blood levels. The following case report concerns a 52-year-old patient with low back pain, left sciatica and numbness in the left leg. Serum uric acid levels were within normal range. MRI and bone scan images suggested an inflammatory-infectious process focussed at L4. After an L4-L5 decompressive laminectomy, histological examination revealed tissue infiltrated with mature plasma cells with negatively birefringent crystals using polarised light consistent with urate deposits.

Tophaceous gout of the lumbar spine mimicking a spinal meningioma

PURPOSE

Although gout is a common metabolic disorder, it usually affects distal joints of the appendicular skeleton. Axial spine involvement is rare, with only 131 cases reported in the literature. The authors report a rare case of lumbar spinal gout mimicking a spinal meningioma.

METHODS

A 77-year-old man with a history of gout presented with chronic low back pain and progressive paraparesis. Imaging revealed a lumbar spine compressive mass lesion with a dural tail signal. The differential diagnosis was thought to be straightforward favoring a spinal meningioma. Tophaceous gout was never considered. The presence of a dural tail associated with the lesion is an interesting detail of this case, that strongly misguided it and to the best of our knowledge it is the first one reported in the literature.

RESULTS

The patient underwent surgery and intra-operative findings were surprisingly different from those expected, revealing a chalky white mass lesion firmly adherent and compressing the dural sac. It was completely excised, leaving the dura intact. Histopathology confirmed the diagnosis of tophaceous gout. The patient was sent to physical therapy and had a complete remission of pain and neurological deficit, regaining his walking capacity.

CONCLUSION

Although spinal gout is rare, it should be considered in the differential diagnosis for patients presenting with symptoms of spinal stenosis, a suspicion of neoplastic lesion of the spine, and a previous history of gout. Early diagnosis can ensure proper and timely medical management, perhaps avoiding neurological compromise and the need for surgery.

Identifying Patient Candidates for IL-1 Inhibition: Lessons From Real-World Cases

A subgroup of patients with gouty arthritis have a chronic recurring form that is particularly difficult to treat. Such patients experience repeated flares and often have abundant tophi. Many also have underlying comorbidities, such as renal impairment, cardiovascular disease, gastrointestinal disorders, obesity, and hypertension, which contraindicate the use of standard anti-inflammatory medications. Five patients with difficult to treat gouty arthritis who were either candidates and/or treated with anti-IL therapy are described.

Severe Hypercalcaemia - Chronic Tophaceous Gout as the Responsible Cause?

The association of chronic tophaceous gout with severe hypercalcaemia is exceptional. In this case, a 42-year old man with a long-standing history of gout arrived at the emergency room with altered mental status. Laboratory work up revealed a uric acid of 14.0 mg/dl, corrected calcium of 14.5 mg/dl, phosphorous of 6.3 mg/dl, parathyroid hormone (PTH) was suppressed (<3.0 pg/ml), 25-dihydroxyvitamin D 25.2 ng/ml, parathyroid hormone related-protein (PTHrP) was 45.0 pg/ml and calcitriol 19.6 pg/ml. Biopsy histopathology result showed deposits of monosodium urate crystals surrounded by granulomatous inflammation. The association of chronic tophaceous gout with severe hypercalcaemia is extremely rare and has been usually described to be secondary to 1-25 dihydroxyvitamin D (calcitriol) secretion. In this case, calcitriol levels were normal and this possibility was excluded. On the other hand, PTHrP had never been, until now, described as the responsible cause of hypercalcaemia in gout. In our case, baseline PTHrP and calcium values were elevated and after medical treatment both returned to normal values. PTHrP usually causes hypophosphataemia and in this case the abnormal renal function could have diminished this last effect.

Gadolinium-enhanced MRI features of acute gouty arthritis on top of chronic gouty involvement in different joints

The aims of the current study are to describe gadolinium-enhanced MRI features of an acute flare of established gouty arthritis in different joints and to examine a possible association between serum uric acid and MRI signs indicative of ongoing inflammation and/or structural joint damage as well as association with disease characteristics and laboratory findings. Twenty-seven male patients with established chronic gout agreed to participate, mean age 47.6 years, and mean disease duration in months 43.2 (±31.8). For all patients, detailed demographic, disease characteristics, and laboratory findings were obtained and correlated with MRI findings. In 27 patients with established gout, a total of 50 MRI studies were performed of the following joints: feet joints (n = 23), ankles (n = 18), knees (n = 5), and hand and wrist joints (n = 4). MRI revealed capsular thickening in 19 patients, bone marrow edema (BME) in 15, soft tissue edema (STE) in 20, joint effusion in 21, bone erosions in 17, cartilaginous erosions in 4, and tenosynovitis in 9 cases. In 17 cases, tophaceous lesions were found. Post contrast MRI showed synovial thickening in seven cases. Positive correlations were observed between serum uric acid levels and the following MRI findings: capsular thickening (r = 0.552, p = 0.003), BME (r = 0.668, p ≤ 0.0001), STE (r = 0.559, p = 0.002), and tenosynovitis (r = 0.513, p = 0.006). Using MRI in chronic gout, important features can be detected like BME, minute cartilaginous erosions, and hypertrophic synovial inflammation in post contrast MR images. Serum uric acid (SUA) was positively correlated with capsular thickening, BME, STE, and tenosynovitis.

Tocilizumab improved clinical symptoms of a patient with systemic tophaceous gout who had symmetric polyarthritis and fever: An alternative treatment by blockade of interleukin-6 signaling

Chronic tophaceous gout is the end stage of gout. We employed a blockade of interleukin-6 signaling therapy by tocilizumab instead of anakinra, an interleukin-1 receptor antagonist, for a 61-year-old Japanese woman diagnosed with tophaceous gout. Laboratory data showed that serum interleukin-6 concentration was elevated. Serum interleukin-1β concentration was under the detectable level, although serum uric acid was elevated due to renal dysfunction. The secretion patterns of interleukin-1β, tumor-necrosis factor-α, interleukin-6, and interleukin-8 from peripheral mononuclear cells isolated from the patient exhibited no remarkable differences compared with those of healthy volunteers. After treatment with the interleukin-6 receptor antagonist tocilizumab, serum interleukin-6 concentration decreased followed by improved clinical symptoms, such as reduced size of the subcutaneous nodules, no fever, and no acute gouty attacks during the treatment. Our case suggests that tocilizumab markedly improves clinical and laboratory manifestations in tophaceous gout with arthritis and fever as well as interleukin-1 blockade therapy.