Comprehensive analysis of calcification frequency and patterns in ovarian tumours using non-contrast CT.

Objectives: To investigate the frequency and patterns of calcification in ovarian tumours and evaluate their association with various histological types and malignancy grades.

Methods: This retrospective study included patients who underwent non-contrast CT between March 2015 and March 2024 and had pathologically confirmed ovarian tumours. CT scans were reviewed for the presence and patterns of calcification (punctate, linear, coarse, and amorphous) by three radiologists. Statistical analysis was performed using the Fisher-Freeman-Halton exact test with Bonferroni correction.

Results: This study included 328 patients (mean age, 55 years; range, 18-88 years). Significant differences in calcification frequency were observed among major tumour categories (p < 0.001), with with germ cell tumours being more calcified and metastases less calcified. Similarly, a significant difference was also found among epithelial tumours (p = 0.005), where mucinous and Brenner tumours were more calcified, whereas serous tumours were less calcified. Benign epithelial tumours showed a significantly higher frequency of calcification than borderline tumours and carcinomas (p < 0.001). When comparing the calcification patterns observed among epithelial tumours, significant differences were found for all calcification patterns: punctate (p = 0.024), linear (p < 0.001), coarse (p < 0.001), and amorphous (p < 0.001). The linear pattern was more common in mucinous tumours, whereas the amorphous pattern was more common in serous and Brenner tumours. Among non-epithelial tumours, germ cell tumours frequently exhibited liner and many calcifications, and immature teratomas were characterised by a mixture of punctate, linear, and coarse calcifications. Granulosa cells and metastatic tumours did not exhibit calcification.

Conclusions: Among epithelial tumours, mucinous and Brenner tumours had a significantly higher frequency of calcification, and benign tumours had a significantly higher frequency of calcification. Amorphous patterns were significantly more common in serous and Brenner tumours, while linear patterns were significantly more common in mucinous tumours.