title: Histopathological characteristics of stenosing flexor tenosynovitis in diabetic patients and possible associations with diabetes-related variables.
abstract: OBJECTIVE
  To compare the histopathological findings of stenosing flexor tenosynovitis (SFTS) in diabetic patients with those in nondiabetic patients and to analyze the predominant characteristics of SFTS in diabetic patients by statistical methods.
  
  
  METHODS
  We included 63 patients (63 specimens) who underwent excision of A1 pulleys for SFTS. A total of 38 patients (38 digits) were diabetic and 25 (25 digits) were nondiabetic. We obtained specimens from the proximal one-third of each A1 pulley and analyzed them by histological and immunohistochemical methods. After we identified the predominant histopathological characteristics of SFTS in patients with diabetes, we performed multiple logistic regression analysis to examine the possible associations between the histopathological characteristics and diabetes-related variables.
  
  
  RESULTS
  We divided histopathological findings into 3 types in both diabetic and nondiabetic groups. Types 1 and 2 showed fibrocartilage metaplasia including fibrocartilage-like cells surrounded by basophilic extracellular substances. Type 2 was characterized by the presence of granulation tissue in the middle layer, which was not recognized in type 1. The granulation tissue contained newly formed microvessels, stromal cells, a small number of inflammatory cells, and extracellular matrix that showed myxomatous degeneration. Type 3 showed a decrease in fibrocartilage-like cells with surrounding extracellular eosinophilic substances, which was similar to hyaline degeneration. The histopathological features of type 2 were found in 68% of the diabetic group and in 28% of the nondiabetic group. This difference was statistically significant. The findings of type 2 were significantly associated with the severity of diabetic retinopathy and hemoglobin A1c values in the diabetic group.
  
  
  CONCLUSIONS
  Type 2 findings were more frequent in the diabetic group than in the nondiabetic group. A pathomechanism to accelerate neovascularization and hypercellularity in the granulation tissue in the middle layer of A1 pulley may exist, especially in diabetic patients with severe retinopathy and poorly controlled hyperglycemia.
authors.affiliation: Department of Orthopaedic Surgery, Saiseikai Central Hospital, Tokyo, Japan. BZA00713@nifty.com
authors.forename: Makoto
authors.initials: M
authors.lastname: Kameyama
authors.forename: Ko-Ron
authors.initials: KR
authors.lastname: Chen
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Mukai
authors.forename: Akira
authors.initials: A
authors.lastname: Shimada
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Atsumi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Yanagimoto
mesh_terms: D000328:Adult; D000368:Aged; D048909:Diabetes Complications / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053682:Tendon Entrapment / Q000473:pathology* / Q000601:surgery*