Unexpected finding of laparoscopic appendectomy: appendix MALT lymphoma in children.

Mucosa-associated lymphoid tissue (MALT) lymphomas comprise a group of indolent B-cell non-Hodgkin lymphomas (NHL), which are rare in pediatric age. The clinical presentation of MALT lymphomas varies according to the location of the lymphoma. We report on a case of MALT lymphoma involving the appendix in a 6-year-old girl. A 6-year-old girl was referred to our institution in May 2005 with a diagnosis of appendicitis. The abdominal ultrasound showed slight effusion in the pelvic fossa. The patient underwent laparoscopic appendectomy using the three-trocar technique. The appendix appeared moderately hyperaemic with slight enlargement of the two-thirds of the distal portion. The postoperative course was uneventful and the girl was discharged on day 1 without any complication. The morphological and immunohistochemical examination showed typical findings of low-grade MALT lymphoma (positivity for CD20, no immunostaing for CD5 and CD10, positivity for anti-lambda light chain and low positivity for Ki-67). Further extensive examinations (abdominal MRI, gastroscopy, colonscopy and capsule endoscopy of the ileum) revealed that the lymphoma was limited to the distal two-third of the appendix (stage IA) and was not associated with any specific infection. At a recent follow-up the patients appeared to be doing well. Appendiceal MALToma is a rather uncommon pathology and, to our knowledge, there is only one report of appendiceal intussusception associated with appendiceal maltoma. According to our experience, low-grade MALToma can be managed by simple appendectomy. The histological examination should be the rule whenever an appendectomy is performed in children.