left overy with complex, partly cystic lesion with internal

I recently had a pelvic ultrasound (transvaginal 1). the results are as follows.. uterus measures 8x4x5 cm . endometrial thickness is 5mm. right overy has a volume of 4 cc. the left overy has a volume of 23 cc. there is free fluid in the pouch of Douglas. the left overy has a complex, partly cystic lesion with internal septations. the kidney's are normal in shape, size and appearance, measuring 12 cm. CONCLUSION; Complex mass left overy. Can some one please tell me if i need to panic yet 8-| ? Or just explain in simple terms what all this means? Thank-you for your time. J