Mucinous cystadenoma of the appendix in a patient with systemic lupus erythematosus

A 38-year-old female with systemic lupus erythematosus presented with abdom inal pain, diarrhea and iron-deficient anemia. Computed tomogram showed a 2 x4 cm inhomogeneous lesion of the right adnexa. An unusual mass was identif ied extending from the appendiceal orifice at colonoscopy, and an 8 cm tubu lar appendix,apparently prolapsed into the cecum,was identified at celiotom y. An appendectomy with cecectomy was performed. On cut section, mucin was extruded from the lumen of the appendix. A mucinous neoplasm of the appendi x with mucinous dissection to the serosal surface was reported at the time of frozen section. No gross ovarian pathology or peritoneal implants were n oted. Cystadenoma with associated mucocele formation was verified by perman ent histology. Mucocele of the vermiform appendix is a rare condition assoc iated with neoplastic transformation in approximately 75% of all cases. Ben ign mucinous cystadenoma of the appendix should be differentiated from cyst adenocarcinoma by frozen section at the time of celiotomy to ensure appropr iate treatment. While systemic lupus erythematosus can lead to cutaneous mu cinosis, an association with mucinous cystadenoma of the appendix has not b een previously reported. Surveillance for metachronous colonic neoplasms is warranted in patients diagnosed with a mucinous neoplasm of the appendix.