Malignant transformation of ovarian mature cystic teratoma with pulmonary blastoma components

Malignant transformation of ovarian mature cystic teratoma with pulmonary blastoma componentsMature cystic teratomas (MCTs), accounting for 20% of ovarian neoplasms 1 , are usually benign.However, malignant transformation can occur in rare cases (0.2-2%) 2 .Squamous cell carcinoma is the most frequent malignant histotype (> 80%), followed by adenocarcinoma, sarcoma, thyroid carcinoma, malignant melanoma and neuroectodermal tumor 2,3 .Early detection of MCTs is a favorable prognostic factor.We report the case of a 77-year-old woman presenting with dyspepsia and pelvic pain, evaluated at Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy, in December 2024.Written informed consent was obtained from the patient for the publication of this case.Ultrasound examination was performed using high-end equipment with a vaginal probe operating at 5-9 MHz.Doppler pulse repetition frequencies were set at 0.3 or 0.7 kHz.A bilocular adnexal lesion measuring 110 × 125 × 125 mm, with smooth external margins, mixed echogenicity and acoustic shadowing, was identified (Figure 1, Videoclip S1).Three floating intracystic components (16 × 15 mm, 33 × 31 mm and 22 × 18 mm) showed 'dots and/or lines' or 'echogenic white ball' appearances (Figure 2).No vascularization on color Doppler or ovarian crescent sign were identified.Subjective assessment suggested a MCT, consistent with the findings of Heremans et al. 1 .The International Ovarian Tumor Analysis (IOTA) Assessment of Different NEoplasias in the adneXa (ADNEX) model estimated a 7.5% risk of malignancy, below the 10% cut-off for malignancy 4 .Serum levels of tumor markers CA 125, human epididymis protein 4 and CA 19-9 were 21 U/mL, 93 pmol/L and 133 U/mL, respectively.