Table 2

Characteristics of adenomas at the initial clearing examination, and first metachronous lesions (histological type, size, and dysplasia are adenoma related and calculations of multiplicity are patient related)

Initial finding (n (%))1st recurrence (n (%))
Histological type
    Tubular1820 (76.9)1095 (83.8)
    Tubulovillous/villous 508 (21.4) 212 (16.2)
    No data 40 (1.7) 4 (0.3)
Size
    ≤10 mm1725 (72.8)1167 (89.0)
    >0 mm 604 (25.5) 127 (9.7)
    No data 39 (1.7) 17 (1.3)
Dysplasia
    Low grade2267 (95.7)1284 (97.9)
    High grade 101 (4.3) 27 (2.1)
    No data 0 (0.0) 0 (0.0)
Multiplicity
    Single 623 (53.8) 846 (73.0)
    Multiple 468 (40.4) 246 (21.2)
    No data 68 (5.8) 67 (5.8)