Table of contents
Appendiceal neoplasm
Background
Overview
Definition
Appendiceal neoplasms are abnormal growths that occur in the appendix. They encompass a range of tumors, including low-grade appendiceal mucinous neoplasm, high-grade appendiceal mucinous neoplasm, and mucinous adenocarcinoma.
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Pathophysiology
The pathophysiology of appendiceal neoplasms is not fully understood, but it is believed to involve genetic mutations that lead to the uncontrolled growth and division of cells in the appendix.
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Epidemiology
The incidence of appendiceal neoplasms in the US is estimated at 0.93 per 100,000 person-years from 2000 to 2017.
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Risk factors
Risk factors for appendiceal neoplasms include advanced age, cystic fibrosis, and familial adenomatous polyposis, although the risk factors are not comprehensively defined.
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Disease course
Clinically, appendiceal neoplasms often present with non-specific symptoms such as abdominal pain, changes in bowel habits, and weight loss. In some cases, they may be discovered incidentally during imaging or surgery for other conditions.
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Prognosis and risk of recurrence
The prognosis of appendiceal neoplasms can vary widely and is influenced by factors such as the stage of the disease at diagnosis and the specific type of neoplasm.
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Guidelines
Key sources
The following summarized guidelines for the evaluation and management of appendiceal neoplasm are prepared by our editorial team based on guidelines from the National Comprehensive Cancer Network (NCCN 2021) and the American Society of Colon and Rectal Surgeons (ASCRS 2019).
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Diagnostic investigations
Clinical examination: as per ASCRS 2019 guidelines, elicit a complete history and perform physical examination in patients with appendiceal neoplasms.
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Diagnostic imaging
Laboratory tests
Preoperative assessment
Diagnostic procedures
Colonoscopy: as per ASCRS 2019 guidelines, perform colonoscopy in patients with confirmed or suspected appendiceal neoplasms.
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Peritoneal cytology
Medical management
Therapeutic procedures
Surgical interventions
Follow-up and surveillance
Follow-up assessment: as per NCCN 2021 guidelines, obtain follow-up assessment in patients with NETs after resection:
Situation
Guidance
12 weeks to 12 months
History and physical examination
Biochemical markers (24-hour urine or serum 5-HIAA, testing for Cushing's syndrome) as clinically indicated
Abdominal +/- pelvic multiphase CT or MRI as clinically indicated
1-10 years (every 1-2 years)
History and physical examination
Biochemical markers (24-hour urine or serum 5-HIAA, testing for Cushing's syndrome) as clinically indicated
Abdominal +/- pelvic multiphase CT or MRI
> 10 years
Obtain surveillance as clinically indicated
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