Chronic Tophaceous Gout Presenting as Bilateral Knee Masses in an Adult Patient: A Case Report.

INTRODUCTION: Gout is a common disorder of uric acid metabolism that leads to the precipitation of monosodium urate crystals. It most commonly affects the first metatarsophalangeal joint but can also affect other joints such as knees, elbows, wrists, and ankles. Chronic gout can present as recurrent episodes of monoarticular or polyarticular inflammatory arthritis, tophaceous soft tissue deposits of monosodium urate crystals, uric acid renal calculi, and/or chronic nephropathy. CASE REPORT: We report the case of a 67-year-old Caucasian male patient with bilateral tophaceous gout to his knees involving the soft tissue and ulcerating skin breakdown to his left knee after an acute traumatic injury. Plain radiographs of the bilateral knees revealed large soft tissue masses anterior to the patella. Magnetic resonance imaging of the left knee was also performed which demonstrated heterogeneous masses consistent with tophi and peripheral enhancement with central necrosis. A diagnostic biopsy was performed to rule out malignancy the results confirmed gouty tophi. We report this case to note the atypical presentation of this disease. CONCLUSION: Chronic tophaceous gout presenting with ulcerating skin breakdown overlying a fungating tophaceous mass is uncommon considering the current availability of effective pharmaceutical treatments for hyperuricemia. Surgical intervention for tophaceous gout is seldom required and is traditionally reserved for atypical cases that present with deformities, severe pain, and joint destruction. Although ulcerative tophi are rare, they can have significant morbidity and greatly impact patients' quality of life. Surgical intervention was indicated in our patient to excise the mass and avoid infective complications.

Cytogenetic Single-Institution Analysis: 101 Consecutive Cases of Soft-Tissue Tumors of the Extremities.

We summarize the results and clinical usefulness of cytogenetic analysis that is routinely performed for musculoskeletal tumors. We performed cytogenetic analysis and traditional histologic evaluation on 101 (51 malignant/ 50 benign) consecutive tumors that were surgically excised. The successful culture rate for cytogenetic analysis was 86% (87/101). Fifty-four percent (25/46) of clearly malignant tumors that were successfully cultured demonstrated significant clonal abnormalities. Fifty-one percent (21/41) of benign tumors that were cultured had significant cytogenetic clonal aberrations. Increased cellular ploidy (> 50 chromosomes/cell) was demonstrated in 14/46 malignant and 1/41 benign tumors that were successfully cultured. Hyperploidy was highly correlated with malignancy (p < 0.001); the only "benign" tumor was a multiply recurrent and giant cell, demonstrating histologic changes consistent with early sarcomatous transformation. As expected, cytogenetic abnormalities frequently occurred in malignant tumors. Surprisingly, almost half of the benign tumors had significant clonal cytogenetic aberrations. Consistent findings of extra chromosomes 5 and 7 in samples of pigmented villonodular synovitis strongly favored a neoplastic origin for this condition. Although the presence or absence of cytogenetic aberrations cannot be used to determine malignant potential, increased cellular ploidy is highly indicative of malignancy. Modern molecular genetics have become more popular, but cytogenetic analysis can be useful for classifying the malignant potential of recurrent and difficult to diagnose tumors of the musculoskeletal system.

Incidental Asymptomatic Fibular Stress Fractures Presenting as Varus Knee Osteoarthritis: A Case Report.

Stress fractures are often missed, especially in unusual clinical settings. We report on 2 patients who presented to our orthopedic surgery clinic with incidental findings of asymptomatic proximal fibular tension side stress fractures in severe longstanding varus osteoarthritic knees. Initial plain films demonstrated an expansile deformity of the proximal fibular shaft, and differential diagnosis included a healed or healing fracture versus possible neoplasm. Magnetic resonance imaging with and without gadolinium was utilized to rule out the latter prior to planned total knee arthroplasty.