Appendiceal neoplasms (ANs) are uncommon and significantly change prognosis and management. With the rapid evolutions in technology, wide availability of computed tomography and public health screening programs such as the BowelScreen program in Australia, ANs are being detected more frequently and at younger ages-most commonly in the 4-5th decade of life. ANs are identified in approximately 1% of histopathological examinations of appendices being removed for primary appendiceal pathology. Approximately one in two patients with ANs will present with signs and symptoms of acute appendicitis, others...

Incidence of ANs: Approximately 80% of ANs are epithelial or neuroendocrine tumours (NETs). Less common are poorly differentiated/malignant NETs, goblet cell carcinoid and mixed cell carcinoid tumours. Rarely sarcomas, lymphoma, metastases, mesenchymal and neural origin tumours may be encountered.

Neuroendocrine Tumors (NETs): The most common type of appendiceal tumor is the neuroendocrine tumours (NET) (approximately 50%) when considering both benign and malignant tumors. NETs are most commonly benign and are characterised as classic or tubular. These arise from subepitheial enterochromaffin cells in the distal third of the appendix and usually follow an indolent cause. A very small proportion (approximately 5%) may cause a carcinoid syndrome and measurements of serum CGA and urine 5-HIAA levels demonstrate this. Tumors non invasive and <1cm confined to the...

Important notes to takeaway: Important for radiology trainees to understand the impact of diagnosing an AN pre-operatively: surgeon able to perform a single stage procedure i.e. appendicectomy vs right hemicolectomy to reduce morbidity and mortality 1% of appendicectomy specimins have an AN,NETs are most common appendiceal tumor (benign and malignant) and epithelial adenocarcinomas are most common malignant tumor of the appendix. Clinically, ANs presents very similar to acute appendicits with NETs more likely to present like acute appendicitis than epithelial tumors. If you don't look,...

C. Reedman-Hawes: Nothing to disclose E. Silverstone: Nothing to disclose

Acknowledgement to the Anatomical Pathology Department at St Vincent's Public Hospital-Sydney. Dr Julia Low, Dr Min Huang, Dr Wade Barrett, A/Prof Tao Yang References: Connor SJ, Hanna GB, Frizelle FA. Appendiceal tumors: retrospective clinicopathologic analysis of appendiceal tumors from 7,970 appendectomies. Dis Colon Rectum 1998;41(1): 75–80. Pickhardt PJ, Levy AD, Rohrmann CA Jr, Kende AI. Primary neoplasms of the appendix: radiologic spectrum of disease with pathologic correlation. RadioGraphics 2003;23(3):645–662. Deshmukh S, Verde F, Johnson PT, Fishman EK, Macura KJ. Anatomical variants and pathologies of the...