Utility of Appendiceal Calcifications Detected on Computed Tomography as a Predictor for an Underlying Appendiceal Epithelial Neoplasm

Ann Surg Oncol. 2017 Nov;24(12):3667-3672. doi: 10.1245/s10434-017-6052-7. Epub 2017 Aug 22.


Background: Mucinous appendiceal neoplasms can contain radiopaque calcifications. Whether appendiceal radiographic calcifications indicate the presence of an appendiceal epithelial neoplasm is unknown. This study aimed to determine whether appendiceal calcifications detected by computed tomography (CT) correlate with the presence of appendiceal epithelial neoplasms.

Methods: From prospective appendiceal and pathology databases, 332 cases of appendiceal neoplasm and 136 cases of control appendectomy were identified, respectively. Only cases with preoperative CT scans available for review were included in the study. Images were reviewed by two abdominal radiologists. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated, and the kappa statistic was used to determine agreement between the radiologists' interpretations.

Results: Interobserver agreement between the radiologists was substantial, with a kappa of 0.74. Appendiceal mural calcifications were identified on CT scans in 106 appendiceal neoplasm cases (32%) and in 1 control case (1%) (P = 0.0001). In the appendiceal neoplasm subgroup, the presence of radiographic calcifications was associated with mucinous histology (35% vs 17%; P = 0.006; odds ratio [OR], 0.38; 95% confidence interval [CI], 0.18-0.78) and with well-differentiated histologic grade (40% vs 24%; P = 0.002; OR, 0.47; 95% CI, 0.29-0.76). The findings showed a sensitivity of 31.9% (95% CI, 26.9-37.2%), a specificity of 99.3% (95% CI, 96-100%), a PPV of 99.1% (95% CI, 94.9-100%), and an NPV of 37.4% (95% CI, 32.4-42.6%).

Conclusion: This case-control study showed that appendiceal mural calcifications detected on CT are associated with underlying appendiceal epithelial neoplasms and that the identification of incidental mural appendiceal calcifications may have an impact on decisions regarding surgical intervention.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Appendiceal Neoplasms / diagnostic imaging
  • Appendiceal Neoplasms / pathology*
  • Calcinosis / diagnostic imaging
  • Calcinosis / pathology*
  • Case-Control Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Neoplasms, Glandular and Epithelial / diagnostic imaging
  • Neoplasms, Glandular and Epithelial / pathology*
  • Predictive Value of Tests
  • Prospective Studies
  • Tomography, X-Ray Computed / methods
  • Tomography, X-Ray Computed / statistics & numerical data*
  • Young Adult