Table 2 Diagnostic pathway (%)

Time [months] from onset symptoms until diagnosis, median (Q1, Q3)

16.9 (4.0–44.0)

Information on MRI

Any closest^a to BL MRI, n (%)

157 (94.6)

Indication of MRI closest to BL, n (%)

 Primary diagnosis

36 (25.7)

 Pre-surgery

16 (11.4)

 Regular postoperative follow-up

56 (40.0)

 Follow-up due to complaints

32 (22.9)

 Missing

17

Characteristics of MRI, n (%)

 Both intra- and extra-articular (n = 147)

90 (61.2)

 Extra-articular tendon/muscle involvement (n = 141)

99 (70.2)

 Ligament involvement (n = 134)

88 (65.7)

TGCT severity, n (%)

 Moderate diffuse

64 (38.6)

 Severe diffuse

83 (50.0)

 Not assessable

19 (11.4)

Information on biopsy

Any biopsy prior BL^b (restricted to the 95 patients with primary diagnosis), n (%)

86 (90.5)

 Excisional biopsy

32 (41.6)

 Core needle biopsy

14 (18.2)

 Arthroscopic biopsy

11 (14.3)

 Surgery for suspected cancer diagnosis

10 (13.0)

 Fine needle aspiration biopsy

6 (7.8)

 Other

9 (11.7)

 Missing

9