Endometriomas in the region of a scar from Cesarean section: sonographic appearance and clinical presentation vary with the size of the lesion.

Purpose: To describe the sonographic (US) appearances of endometriomas developed in the vicinity of a scar from Cesarean section and compare sonographic and clinical characteristics of large (> or =3 cm) scar endometriomas (LSEs) with small scar endometriomas (SSEs).

Method: Twenty-eight consecutive women (mean age, 31 years; range, 20-42) with 31 scar endometriomas (mean diameter, 2.7 cm; range, 0.7-6 cm) were examined by US, including color Doppler imaging prior to surgery. Clinical and US findings in women with LSE were compared with those of women with SSE.

Results: Twelve patients had 12 LSEs with a mean longest diameter of 4.1 cm (range, 3-6 cm); in 1 case, a large nodule was associated with a small lesion. Sixteen women had 18 SSEs with a mean lesion size of 1.8 cm (range, 0.7-2.6 cm).The mean time interval between the last Cesarean section and hospital admission was longer in patients with LSE (66 versus 40 months; p < 0.01) as was the mean duration of symptoms before admission (43 versus 17 months; p < 0.01); in addition, 41.6% of patients with LSE had undergone previous inconclusive diagnostic examinations (CT, MRI, fine needle aspiration, or laparoscopy) compared with 0% in patients with SSE (p < 0.05). LSEs more frequently showed cystic portions and fistulous tracts (p < 0.05), loss of round/oval shape (p < 0.05), and increased vascularity (p < 0.05) than SSEs did.

Conclusion: LSEs were associated with a delay in diagnosis and some US findings that could result in further diagnostic difficulties.