Laboratory investigations: Mildly high CRP.  Normal WBC, CEA, CA 19.9, and PSA. 

The patient underwent laparoscopic appendectomy.

Histopathology: Appendiceal mucinous neoplasia, low-grade (LAMN) confined to the muscularis propria, stage Tis (in situ) with calcifications and ossifications in the tip. Presence of acellular mucin dissection in the submucosa. Clear surgical margins.

Peritoneal fluid: Negative for malignant cells.