Background: Fine needle aspiration (FNA) of the appendiceal mucocele is generally avoided because of fear that puncture of a distended viscus will lead to rupture or seeding of neoplastic cells and result in localized or diffuse pseudomyxoma peritonei. Cytologic reports regarding FNA of appendiceal mucoceles are virtually nonexistent.
Case: A 55-year-old male with a preoperative diagnosis of an infectious process with interloop abscess formation underwent computed tomography-guided aspiration of the mass. FNA showed clusters of intestinal type epithelium with mild nuclear crowding, hyperchromasia and atypia in a mucinous background.
Conclusion: The differential diagnosis of a neoplastic appendiceal cystic tumor based on the FNA findings could be difficult and should be made only in conjunction with clinical findings. FNA of an appendiceal mucocele may be safe when a small-gauge needle and retroperitoneal approach are utilized.