SONOGRAPHY OF BENIGN TERATOMAS

Purpose: Due to their sonomorphical appearance mature cystic teratomas are often correctly diagnosed ''at first sight''. However the complex and variable architecture of the lesions frequently leads to their cl assification as malignant if sonographic tumour scores are applied. Ma terial and Methods: In the Department of Gynaecology Hospital at the U niversity of Freiburg, we performed between 1988 and 1996 a preoperati ve ultrasound examination of 117 cystic teratomas in 110 patients. In 63 of these rumours Colour-Doppler sonography was also used. Results: As typical sonographic markers for the diagnosis of cystic teratomas w as used the following criteria: a line pattern in the fluid phase of t he tumour (seen in 62 [53%] cases); homogeneous echogenic structure (s een in 102 [82%] cases); shadowing (seen in 50 [43%] cases). 96% of th e tumours showed at least one of these markers. In 62% of dermoid plug s with hairs typical sonographic criteria were present. In 25% of the cases with osseous or dental structures characteristics shadowing was observed. The ranking of the sonographic diagnosis was assessed for 75 4 ovarian rumours including 71 cystic teratomas. The dermoid tumours w ere predicted with a sensitivity of 94.3%, a specificity of 99.3%, an accuracy of 98.8% and a positive or negative predictive value of 93% a nd 99.3%, respectively. Using the colour Doppler technique we were abl e to predict the tumour status of the complex cystic teratomas correct ly in 91% and 93% of the cases, respectively, using one of the followi ng parameters: number of tumour arteries, maximum systolic velocity or sum of maximum systolic velocities. This figure dropped to 68% if min imal resistance index was used. Conclusion: Basing on typical markers, sonographic diagnosis of cystic teratomas is very reliable. Colour Do ppler sonography is a useful, independent method to supplement determi nation of the tumour status of teratomas.