Incidental Appendiceal Adenocarcinoma Discovered After Ileocecectomy for Recurrent Small Bowel Obstruction: A Case Report.

We report a case of moderately differentiated appendiceal adenocarcinoma discovered on histopathologic examination following ileocecectomy for recurrent SBO in a woman in her early 50s with a history of stage III rectal adenocarcinoma in remission. Notably, serial surveillance imaging over two years had demonstrated a radiographically normal appendix prior to the obstructive presentation. Immunohistochemical and histopathologic features confirmed a metachronous primary malignancy rather than metastatic recurrence. This case exemplifies the diagnostic challenge posed by occult appendiceal neoplasms, the importance of meticulous histopathologic evaluation of all resected specimens, and the need to consider rare malignant etiologies in patients with recurrent bowel obstruction and a prior colorectal cancer history.