BACKGROUND Incidental appendiceal neoplasms account for 1-2% of appendectomies. Mucinous neoplasms and carcinoids are the most frequent lesions, with an incidence of 0.6% and 0.3-0.9%, respectively. Appendiceal collision tumors are extremely rare and result from the proliferation of 2 different cellular lines. This report describes a young woman with a collision tumor composed of a low-grade appendiceal mucinous neoplasia (LAMN) and an appendiceal neuroendocrine tumor (ANET). CASE REPORT A 31-year-old woman was admitted to our institution presenting with abdominal pain and dysuria. After ultrasound assessment of a dilated appendix with wall thickening and distension by anechogenic material, a diagnosis of acute appendicitis was made. The patient, after a period of antibiotic therapy and observation, underwent an urgent laparoscopic appendectomy due to worsening condition. Surprisingly, the histological exam revealed a Tis LAMN extending from the base of the appendix to the resection margins, and a T3 grade-1 ANET, chromogranin-A and synaptophysin-positive, with a Ki67 less than 1%. On the basis of histological examination and European Neuroendocrine Tumor Network guidelines, in light of the positive LAMN resection margin and ANET mesoappendiceal invasion, after multidisciplinary team discussion, an elective laparoscopic hemicolectomy was indicated. The patient is now in good condition following a regular 5-year follow-up. CONCLUSIONS A collision LAMN and ANET is an exceedingly rare condition. The heterogeneity of clinical presentation and lack of solid evidence seem to recommend a tailored management. Laparoscopy is a safe and useful tool in localized mass excision.

Villa, M., Sforza, D., Siragusa, L., Martina Guida, A., Ciancio Manuelli, M., Maria Pirozzi, B., et al. (2021). A Low-Grade Appendiceal Mucinous Neoplasia and Neuroendocrine Appendiceal Collision Tumor: A Case Report and Review of the Literature. THE AMERICAN JOURNAL OF CASE REPORTS [10.12659/ajcr.927876].

A Low-Grade Appendiceal Mucinous Neoplasia and Neuroendocrine Appendiceal Collision Tumor: A Case Report and Review of the Literature

Massimo Villa
;
Daniele Sforza;Giampiero Palmieri;Michele Grande
2021-02-01

Abstract

BACKGROUND Incidental appendiceal neoplasms account for 1-2% of appendectomies. Mucinous neoplasms and carcinoids are the most frequent lesions, with an incidence of 0.6% and 0.3-0.9%, respectively. Appendiceal collision tumors are extremely rare and result from the proliferation of 2 different cellular lines. This report describes a young woman with a collision tumor composed of a low-grade appendiceal mucinous neoplasia (LAMN) and an appendiceal neuroendocrine tumor (ANET). CASE REPORT A 31-year-old woman was admitted to our institution presenting with abdominal pain and dysuria. After ultrasound assessment of a dilated appendix with wall thickening and distension by anechogenic material, a diagnosis of acute appendicitis was made. The patient, after a period of antibiotic therapy and observation, underwent an urgent laparoscopic appendectomy due to worsening condition. Surprisingly, the histological exam revealed a Tis LAMN extending from the base of the appendix to the resection margins, and a T3 grade-1 ANET, chromogranin-A and synaptophysin-positive, with a Ki67 less than 1%. On the basis of histological examination and European Neuroendocrine Tumor Network guidelines, in light of the positive LAMN resection margin and ANET mesoappendiceal invasion, after multidisciplinary team discussion, an elective laparoscopic hemicolectomy was indicated. The patient is now in good condition following a regular 5-year follow-up. CONCLUSIONS A collision LAMN and ANET is an exceedingly rare condition. The heterogeneity of clinical presentation and lack of solid evidence seem to recommend a tailored management. Laparoscopy is a safe and useful tool in localized mass excision.
feb-2021
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore MED/18 - CHIRURGIA GENERALE
English
Con Impact Factor ISI
Appendiceal Mucinous Neoplasia; Neuroendocrine Appendiceal Collision Tumor; appendicitis
Villa, M., Sforza, D., Siragusa, L., Martina Guida, A., Ciancio Manuelli, M., Maria Pirozzi, B., et al. (2021). A Low-Grade Appendiceal Mucinous Neoplasia and Neuroendocrine Appendiceal Collision Tumor: A Case Report and Review of the Literature. THE AMERICAN JOURNAL OF CASE REPORTS [10.12659/ajcr.927876].
Villa, M; Sforza, D; Siragusa, L; Martina Guida, A; Ciancio Manuelli, M; Maria Pirozzi, B; Pocci, M; Palmieri, G; Grande, Msf
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/267000
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