title: Giant cell tumour of tendon sheath of the digits. A systematic review.
abstract: BACKGROUND
  We reviewed the literature to evaluate the demographic, clinical and histological profile of giant cell tumour of tendon sheath of the digits (GCTTSD). The overall recurrence rate and the factors affecting tumour recurrence were also assessed.
  
  
  METHODS
  We searched for published articles regarding the GCTTSD in the English literature the last 30 years using the PubMed search engine. All retrieved papers were analysed and their reference lists were also screened if relevant. Clinical studies with less than five patients and follow-up less than 2 years were excluded from further evaluation. For each report, information was gathered related to trial characteristics and study population. Location and multicentricity of lesions, kind and severity of symptoms, type of applied treatment modality and histopathological features of the excised tumours were additionally recorded. A meta-analysis for estimating the pooled recurrence rate after surgical excision was also conducted. Statistical significance was assumed for p ≤0.05.
  
  
  RESULTS
  We found 21 studies with histological confirmation of GCTTS. However, only 10 studies including 605 patients were reviewed according to selection criteria (average follow-up 36.7 to 79 months). The male-to-female ratio was 1:1.47 (p < 0.005) and the mean age ranged from 32 to 51 years. Pain or sensory disturbances reported only in 15.7% and 4.57% of cases, respectively. A definite history of trauma recorded in 5% of lesions. The most frequent tumour location was the index finger (29.7%). In total, 14.8% of patients had tumour recurrence. Type I tumours (single lesions) were more frequently detected (78.7%) than type II tumours (two or more distinct tumours that were not joined together) (21.3%) but the latter were associated with a higher recurrence rate (p < 0.001). Study design also affected the possibility of recurrence as it was lower in prospective studies compared to retrospective studies (p = 0.003). Even though bone erosion was detected in 28.39%, recurrence was not more common in this group. In addition, recurrence was not significantly associated with a specific finger or phalanx.
  
  
  CONCLUSIONS
  Intrinsic biology of the tumour seems to play a more fundamental role in recurrence than tumour location or local invasiveness. More prospective well-designed studies including a large number of cases are necessary to identify tumours prone to recurrence and determine the proper treatment protocol for each individual patient.
authors.forename: Elias
authors.initials: E
authors.lastname: Fotiadis
authors.forename: Alexis
authors.initials: A
authors.lastname: Papadopoulos
authors.forename: Theodoros
authors.initials: T
authors.lastname: Svarnas
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Akritopoulos
authors.forename: Nick P
authors.initials: NP
authors.lastname: Sachinis
authors.forename: Byron E
authors.initials: BE
authors.lastname: Chalidis