Synovial Biopsy in the Diagnosis of Crystal-Associated Arthropathies

J Clin Rheumatol. 2020 Jun;26(4):142-146. doi: 10.1097/RHU.0000000000000993.


Background/ objective: This study seeks to assess the utility of synovial biopsy in the diagnosis of crystal-associated arthropathies (CAAs) in a clinical setting.

Methods: In this retrospective study, we reviewed biopsy reports involving synovial tissue between 1988 and 2015. We then reviewed the records of patients where the biopsy was performed for a clinical suspicion of CAA-the clinical group-and calculated the frequency of a positive diagnosis. The t test, Mann-Whitney-Wilcoxon test, and Fisher test were used to compare clinical characteristics of patients with and without a tissue diagnosis of CAA. We also reviewed cases of unexpected detection of crystalline disease involving synovial tissue-the incidental group.

Results: Among 2786 biopsies involving the synovium, we identified 65 cases in the clinical group and 33 cases in the incidental group. In the clinical group, a relevant diagnosis was obtained from synovial tissue in 36.9%, and a CAA was diagnosed in 20%. Restricting analysis to clinical biopsies performed for a primary suspicion of CAA, a relevant diagnosis was obtained in 61.3%, and a CAA was diagnosed in 38.7%. The incidental group comprised 1.2% of all synovial biopsies and included 7 mass lesions. Basic calcium phosphate was not reported on any biopsy in the study period.

Conclusions: Synovial biopsy is a diagnostic option when suspected CAA is resistant to conventional modes of diagnosis. Crystalline diseases should be considered in the differential diagnosis of musculoskeletal mass lesions mimicking neoplasms.

MeSH terms

  • Aged
  • Biopsy* / methods
  • Biopsy* / statistics & numerical data
  • Bone Neoplasms / diagnosis*
  • Crystal Arthropathies* / diagnosis
  • Crystal Arthropathies* / epidemiology
  • Crystal Arthropathies* / pathology
  • Crystal Arthropathies* / physiopathology
  • Diagnosis, Differential
  • Female
  • Gout* / epidemiology
  • Gout* / pathology
  • Gout* / physiopathology
  • Humans
  • Incidental Findings
  • Male
  • Middle Aged
  • Muscle Neoplasms / diagnosis*
  • Symptom Assessment / methods
  • Symptom Assessment / statistics & numerical data
  • Synovial Membrane / pathology*
  • United States / epidemiology