Tophaceous pseudogout in the knee joint mimicking a soft-tissue tumour: a case report

Pathogenesis of calcium pyrophosphate deposition disease

Calcium pyrophosphate deposition disease is defined by the presence of calcium pyrophosphate (CPP) crystals in articular cartilage and is the fourth most common type of arthritis in adults. Despite its high prevalence, the etiology of CPPD disease remains unclear and no specific therapies currently exist. It has been known for several decades that abnormalities of cartilage pyrophosphate metabolism are common in patients with CPPD disease, and this classic work will be reviewed here. Recent studies of rare familial forms of CPPD disease have provided additional novel information about its pathophysiology. This work suggests that CPPD disease occurs through at least two unique and potentially intertwined biomolecular pathways. We are hopeful that a detailed understanding of the components and regulation of these pathways will lead to improved therapies for this common disease.

Calcium Pyrophosphate Dihydrate Crystal Deposition Disease Involving the Ligamentum Flavum of the Cervical Spine with Intense Enhancement on MRI: A Case Report

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease is characterized by chondrocalcinosis, which mainly affects the knees, wrists, pelvis, and rarely, the spine. According to previous reports, CPPD crystal deposits display heterogeneous enhancement on MRI. When combined with inflammation of the surrounding soft tissue, strong enhancement by CPPD crystal deposition may appear similar to imaging features of other conditions such as infectious spondylitis. In these conditions, CT plays an important role in differential diagnosis. Here, we present a case of CPPD crystal deposition disease in the ligamentum flavum of the cervical spine that showed intense enhancement on MRI.

An Unusual Case of Huge Tophaceous Pseudogout Mimicking as a Tumor-Like Lesion around the Ankle Joint: A Case Report and Literature Review

Pseudogout or calcium pyrophosphate dihydrate deposition disease (CPPD) primarily affects the joints and the periarticular tissues. Tophaceous or tumoral pseudogout is a rare form of this disease which is seen around the joints of extremities. It can be misdiagnosed as a neoplastic condition because of its clinicoradiological similarities, and thus, a proper histopathological examination is indispensable. We report one such case of extra-articular deposition of the CPPD crystals in a 65-year-old man who presented with an asymptomatic swelling around the left ankle. Radiographs showed a dense homogenous calcification, and FNAC revealed dense calcium deposits with numerous rhomboid-shaped crystals. It was managed by en bloc excision, and postoperative biopsy reports confirmed the diagnosis. Possibility of pseudogout should be kept as a differential diagnosis in patients presenting with calcified soft tissue swellings and should be subjected to a detailed histopathological examination for confirmation.

Calcium Pyrophosphate Dihydrate Crystal Deposition Disease Simulating Osteoarthrosis of the Knee: A Case Report

OBJECTIVE

The purpose of this case report is to describe a case where calcium pyrophosphate dehydrate crystal deposition disease (CPPD) simulated osteoarthritis of the knee.

CLINICAL FEATURES

A 78-year-old woman had a 2-week history of severe right knee pain accompanied by mild swelling. The onset was sudden and did not involve a history of trauma or previous injury to the right knee. Inspection and palpation revealed pain along the medial joint line and marked difficulty ambulating. Results of Lachman's test, anterior drawer test, and posterior sag sign were negative upon orthopedic assessment. Diagnostic imaging was performed and showed degenerative changes with diffuse calcification of the fibrocartilage and hyaline articular cartilage within the knee joint and the medial collateral ligament consistent with the appearance of CPPD crystal deposition.

INTERVENTION AND OUTCOME

Low-level laser therapy was performed to the affected medial joint line of the knee, and knee stabilization exercises were given. Lower Extremity Function Scale changed from 34% to 60% after 4 weeks of care.

CONCLUSION

Although knee osteoarthritis is much more common than knee CPPD, it is important to consider both diagnoses in elderly patients who present with unilateral knee pain. Diagnosis should be based on clinical presentation, history, and radiographic or histological means to ensure accuracy and proper diagnosis.

A Rare Case of Tumoral Calcium Pyrophosphate Dihydrate Crystal Deposition Disease of the Wrist Joint

Introduction. Tumoral calcium pyrophosphate dihydrate (CPPD) crystal deposition disease (CPPDCD), also known as tophaceous calcium pyrophosphate deposition disease (CPDD), is a tumorlike lesion, and it should be distinguished from usual CPDD that causes severe joint inflammation and arthralgia. A case of tumoral CPPDCD of the wrist joint that required differentiation from synovial osteochondromatosis is described. Case Presentation. The patient was a 78-year-old woman with a 5-year history of nodular lesions at the right wrist that had gradually increased in size. An excisional biopsy and a histological examination of the excised nodular lesions by hematoxylin and eosin (H&E) staining were performed, demonstrating numerous polarizable, rhabdoid, and rectangular crystals, surrounded by fibroblasts, macrophages, and foreign body-type giant cells, consistent with tumoral CPPDCD. Conclusion. Tumoral CPPDCD, especially at the wrist joint, is rare, and, to the best of our knowledge, only 2 articles have been published. This case seems to need further follow-up for recurrence, because tumoral CPPDCD may recur after complete or incomplete surgical excision.

Calcium Pyrophosphate Dihydrate Crystal Deposition Disease of the Sternoclavicular Joint

Deposition of calcium pyrophosphate dihydrate (CPPD) crystals in the articular structures affects predominantly temporomandibular, knee, hip, spine, and wrist joints, and is a rare condition, often mimicking malignancy. Sternoclavicular joint is extremely rarely involved. We present a patient with swelling of the right upper extremity, in whom on computed tomography a mass posterior to the sternoclavicular joint causing compression of the brachiocephalic vein was detected. A modified resection arthroplasty was performed, and the histopathological findings revealed massive deposits of CPPD in the articular cartilage. To our knowledge, there is only one similar case published in the literature.

Tophaceous calcium pyrophosphate dihydrate deposition disease of the knee mimicking an aggressive soft tissue tumour

Calcium pyrophosphate crystal deposition disease (CPPD), previously pseudogout, is the second most common crystal arthropathy after gout. There is increased radiographic prevalence associated with age, trauma and several metabolic disorders. Tophaceous CPPD (T-CPPD) is a rare form of CPPD which, though non-neoplastic, mimics a bone or soft tissue malignancy. T-CPPD usually presents as a mass in the temporomandibular joint and occasionally in the paraspinal tissues, but rarely in the joints of the extremities. We present an exceptionally rare case of T-CPPD that was subtle on plain radiography, presenting as a soft tissue mass in the knee joint.

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.