MSSP578: CORRELATION OF IMAGING CHARACTERISTICS WITH APPENDICEAL NEOPLASMS
Todd Smolinsky; Franklin Valdera; Patrick McCarthy; Brooke Army Medical Center
Introduction: There are imaging criteria defining a normal appendix, but guidance as to whether specific radiologic abnormalities should be considered an indication for elective appendectomy is lacking. This study sought to characterize imaging qualities related to appendiceal neoplasms.
Methods: Retrospective chart review of 5 academic institutions from January 2005-June 2017 of all patients (pts) taken for elective appendectomy after abnormal imaging findings were noted. All underwent open/laparoscopic appendectomy. Those taken for suspected acute appendicitis or who underwent incidental appendectomy during another primary operation were excluded. Pathologic diagnoses were divided into neoplastic (epithelial and non-epithelial) or benign groups. Appendiceal dilation, imaging abnormalities, and demographic correlations were compared using chi square or Fisher exact testing.
Results: A total of 54 pts were included with an overall neoplasm rate of 43% (23/54). These included mucinous neoplasm (19), adenocarcinoma (1), adenoma (1), and neuroendocrine tumor (2). Median age was 47 years old (20-84), and 64% (35/54) were male. Age and gender were not associated with increased rates of appendiceal neoplasm (p=0.71, p=0.80, respectively). Median diameter was 12mm, 95% CI (10-15). In pts under 50 years old, the rate of appendiceal neoplasm was 59% (10/17) with appendiceal dilation ≥10mm, while the rate of neoplasm decreased to 0% (0/7) in pts under 50 years old when appendiceal dilation was < 10mm, p=0.02. Preoperative report of a solid or cystic mass was found in 22% (12/54) and associated with a neoplasm rate of 75% (8/12). Calcifications were present in 9% (5/54) of pts with a rate of 80% (4/5) having a neoplasm. Appendicoliths were present in 13% (7/54) of pts with no neoplasms associated, p=0.001. PET avidity was an indication for appendectomy in 2 pts. In each case the pathology was benign.
Conclusions: There is a high rate of neoplasm in elective appendectomy for imaging abnormalities. Certain groups, such as <10mm appendix in pts under 50 years of age, or presence of an appendicolith, are associated with low rates of neoplasm. Larger studies are required to confirm if these are groups that can be safely observed without surgery.