Duplication of the appendix masquerading as appendiceal tumor: a case report

Abstract Background This case report highlights the exceptional rarity of appendix duplication in adults, a condition that closely mimics appendiceal tumors, posing diagnostic challenges. The novelty of this case lies in its presentation of a Type A duplication, emphasizing the diagnostic intricacies involved in distinguishing it from other pathologies. Case presentation We present the case of a 69-year-old male with a history of hypertension, hyperuricemia, and duodenal gastric ulcer, who presented with a positive occult blood test. Lower gastrointestinal endoscopy revealed an appendiceal orifice with atypical hyperemia and edema. Subsequent imaging and biopsy results suggested an appendiceal tumor, prompting laparoscopic ileocecal resection. Intraoperative findings revealed an unremarkable appendix, but histopathological analysis unveiled appendiceal duplication, characterized by bifurcation into two lumens within a thick serosal wall. The patient was discharged without complications. Conclusions This case underscores the importance of recognizing appendix duplication as a rare differential diagnosis for appendiceal tumors. Surgeons should remain vigilant, especially in cases of Type A duplication, where preoperative diagnosis remains challenging. Early identification can avert potential complications and missed congenital anomalies

Structural and functional analysis of a 0.5-Mb chicken region orthologous to the imprinted mammalian Ascl2/Mash2–Igf2–H19 region

Previous studies revealed that Igf2 and Mpr/Igf2r are imprinted in eutherian mammals and marsupials but not in monotremes or birds. Igf2 lies in a large imprinted cluster in eutherians, and its imprinting is regulated by long-range mechanisms. As a step to understand how the imprinted cluster evolved, we have determined a 490-kb chicken sequence containing the orthologs of mammalian Ascl2/Mash2, Ins2 and Igf2. We found that most of the genes in this region are conserved between chickens and mammals, maintaining the same transcriptional polarities and exon–intron structures. However, H19, an imprinted noncoding transcript, was absent from the chicken sequence. Chicken ASCL2/CASH4 and INS, the orthologs of the imprinted mammalian genes, showed biallelic expression, further supporting the notion that imprinting evolved after the divergence of mammals and birds. The H19 imprinting center and many of the local regulatory elements identified in mammals were not found in chickens. Also, a large segment of tandem repeats and retroelements identified between the two imprinted subdomains in mice was not found in chickens. Our findings show that the imprinted genes were clustered before the emergence of imprinting and that the elements associated with imprinting probably evolved after the divergence of mammals and birds