**2. Case report**

P.A., a 6-year-old girl, was referred to our institution in May 2005 with a diagnosis of appendicitis. The girl had been complaining of right lower abdominal pain for 6 months. More recently, the pain was exacerbated by walking and coughing. Abdominal ultrasound showed a slight effusion of the pelvic fossa. Her postnatal history showed some period of constipation spaced by regular daily evacuations. Blood examinations showed neutrophil leucocytosis. The patient underwent laparoscopic appendectomy using the three-trocar technique, three endo-loops and the Liga-Sure for the hemostasis. During the laparoscopic exploration no hyperplastic mesenteric lymphnode was found. The appendix appeared moderately hyperemic with a slight enlargement of two-thirds of its distal portion (Fig. 1).

The postoperative course was uneventful and the girl was discharged on day 1, without any complications. The appendix underwent a routine histological examination. The morphological appearance showed thickened lamina propria and submucosa, which were occupied by pseudonodules of immunocompetent cells (Fig. 2), characterized by lymphocytes with small nuclei with a narrow cytoplasmic rim and plasma cell (Fig. 3). Immunohistochemical studies revealed positivity for CD20 (CD20, pan B cell), and

<sup>\*</sup> Corresponding Author

Appendiceal MALT Lymphoma in Childhood – Presentation and Evolution 421

Fig. 3. Hematoxylin–eosin staining. Hyperdense lymphocytic population with small nuclei and narrow cytoplasmic rim and some plasmacytoid and monocytoid elements with great

negativity for CD5 (CD5, Pan T cell, and B cell subsets) and CD10 using monoclonal antibodies, and positivity for anti-k (immunoglobulin light chain) using polyclonal antibodies, in addition to a low positivity to Ki-67 (proliferation-associated marker). Extensive further examination revealed that the lymphoma was restricted to the distal

Abdominal MRI, OGDS, and capsule endoscopy of the ileum were all negative; the search for *H. pylori* was also negative. No chemotherapy was performed. After a 15-months followup, the patient was doing well (Marte et al., 2008). Calprotectin and clinical evaluation were repeated yearly showing no problem and the patient was asymptomatic. 3 year after, the yearly follow-up showed a slight increase of fecal calprotectin values (40µg/g) with recurrent abdominal pain and occasional episodes of diarrhea. The girl underwent a new clinical evaluation, small bowel radiological contrast study, videocapsule, OGDS, and colonoscopic examination. No fever or weight loss was present; erythrocyte sedimentation rate, C-reactive protein level were slightly higher. Perinuclear antineutrophil cytoplasmatic antibodies (pANCA) and Anti-Saccharomyces cerevisiae (ASCA) antibodies are not

The small bowel x-ray contrast, OGDS and videocapsule study demonstrated no abnormalities. Colon biopsies revealed a mild nonspecific IBD extending till 90 cm from the

portion of the appendix (stage IA) and was not associated with any specific infection.

and hyperchromatic nuclei.

increased too.

anal verge. (Fig.4,5,6,7)

Fig. 1.

Fig. 2. Hematoxylin–eosin staining. The wall of appendix is thickened, and occupied by a compact nodular formation. The serous and muscular tunic appear thin.

Fig. 2. Hematoxylin–eosin staining. The wall of appendix is thickened, and occupied by a

compact nodular formation. The serous and muscular tunic appear thin.

Fig. 1.

Fig. 3. Hematoxylin–eosin staining. Hyperdense lymphocytic population with small nuclei and narrow cytoplasmic rim and some plasmacytoid and monocytoid elements with great and hyperchromatic nuclei.

negativity for CD5 (CD5, Pan T cell, and B cell subsets) and CD10 using monoclonal antibodies, and positivity for anti-k (immunoglobulin light chain) using polyclonal antibodies, in addition to a low positivity to Ki-67 (proliferation-associated marker). Extensive further examination revealed that the lymphoma was restricted to the distal portion of the appendix (stage IA) and was not associated with any specific infection.

Abdominal MRI, OGDS, and capsule endoscopy of the ileum were all negative; the search for *H. pylori* was also negative. No chemotherapy was performed. After a 15-months followup, the patient was doing well (Marte et al., 2008). Calprotectin and clinical evaluation were repeated yearly showing no problem and the patient was asymptomatic. 3 year after, the yearly follow-up showed a slight increase of fecal calprotectin values (40µg/g) with recurrent abdominal pain and occasional episodes of diarrhea. The girl underwent a new clinical evaluation, small bowel radiological contrast study, videocapsule, OGDS, and colonoscopic examination. No fever or weight loss was present; erythrocyte sedimentation rate, C-reactive protein level were slightly higher. Perinuclear antineutrophil cytoplasmatic antibodies (pANCA) and Anti-Saccharomyces cerevisiae (ASCA) antibodies are not increased too.

The small bowel x-ray contrast, OGDS and videocapsule study demonstrated no abnormalities. Colon biopsies revealed a mild nonspecific IBD extending till 90 cm from the anal verge. (Fig.4,5,6,7)

Appendiceal MALT Lymphoma in Childhood – Presentation and Evolution 423

Fig. 6. Absent mucosal surface epithelium with focal reduction of the glands. The lamina

propria is edematous, site of microbleeds and is infiltrated by elements of immunocompetent and heaps of eosinophils. (20 X). 90 cm from the anal verge.

Fig. 4. Colonoscopy. Rectum and sigmoid colon: mucosal redness, nonspecific inflammatory pattern.

Fig. 5. Colonoscopy. Rectum and sigmoid colon: mucosal redness, nonspecific inflammatory pattern.

Fig. 4. Colonoscopy. Rectum and sigmoid colon: mucosal redness, nonspecific inflammatory

Fig. 5. Colonoscopy. Rectum and sigmoid colon: mucosal redness, nonspecific inflammatory

pattern.

pattern.

Fig. 6. Absent mucosal surface epithelium with focal reduction of the glands. The lamina propria is edematous, site of microbleeds and is infiltrated by elements of immunocompetent and heaps of eosinophils. (20 X). 90 cm from the anal verge.

Appendiceal MALT Lymphoma in Childhood – Presentation and Evolution 425

Fig. 8. Recto-sigmoid junction (10X). Mucosal home-based micro-inflammatory polyps. The glandular portion is moderately reduced. The lamina propria is edematous and infiltrated

by immunocompetent elements.

Fig. 7. Rectum (20X): 2 small erosions of the mucosa, glandular patrimony preserved, but low in mucus cells. The lamina propria is diffusely infiltrated by immunocompetent cells (lymphocytes and plasma cells).

Fig. 7. Rectum (20X): 2 small erosions of the mucosa, glandular patrimony preserved, but low in mucus cells. The lamina propria is diffusely infiltrated by immunocompetent cells

(lymphocytes and plasma cells).

Fig. 8. Recto-sigmoid junction (10X). Mucosal home-based micro-inflammatory polyps. The glandular portion is moderately reduced. The lamina propria is edematous and infiltrated by immunocompetent elements.

Appendiceal MALT Lymphoma in Childhood – Presentation and Evolution 427

rectum (Matsudo et al., 1997) following *H. pylori* eradication. Other risk factors for MALT lymphoma include autoimmune diseases like Hashimoto thyroiditis or Sjogren syndrome, and Borrelia burgdorferi for skin lymphoma. A further prerequisite for the development of MALT lymphoma in children may be the presence of HIV infection (Teruya-Feldestein et al., 1995; Mo et al., 2004). In some patients no risk factors can be identified. The most common sites are the stomach and salivary glands. Others sites are: ocular adnexa, the lungs, thyroid and the skin (Zucca et al., 2000). Some retrospective analyses of histopathological results of appendectomy specimens performed for acute appendicitis in a large sample of patients, including children, report a prevalence of appendiceal malignant tumors ranging from 0.4 (Tchana et al., 2006) to 1.5% (Ravi et al., 2006). Among the malignant tumors, carcinoids have the highest incidence (Tchana et al., 2006; Ravi et al., 2006) and 70–90% of these tumors are discovered incidentally because they are usually restricted to the distal appendix (Akerstrom, 1989; Aranha & Greenle, 1980). From a review of the literature we found only one case of appendix lymphoma in paediatric age presenting with intussusception symptoms (Karabulut et al., 2005). Our report probably represents the first case of MALT lymphoma of the appendix found accidentally in a child during an appendectomy. MALT lymphomas manifest with aspecific symptoms. In our case, the clinical presentation was characterized by recurrent abdominal pain, and the only element of suspicion was the enlargement of the distal portion of the appendix. The subsequent evolution to a mild form of IBD could be considered as an evolution of the appendiceal malt-limphoma for which the phenomenon should be considered a prodromal presentation of a more extensive bowel disease which require a close follow-up and specific therapy (Aomatsu et al., 2011). Otherwise we can't exclude that the subsequent IBD could be an autonomous, subsequent disease considered that, also in this case, there are no data in the Literature. Furthermore, given the previous appendiceal malt-lymphoma, the efficacy of mesalazine alone, without the use of immunosuppressive drugs, can be considered a very favorable factor in our case. In conclusion, even if the occurrence of malignant appendiceal pathology in children is rare (Setty & Termuhlen, 2010), the probability that it is asymptomatic is very high. According to our experience, our case suggests that histological examination should always be performed following appendectomy in children and that if a MALT lymphoma were discovered, a close follow-up is strongly recommended, not only for the MALT lymphoma recurrence but

also for its possible evolution towards an inflammatory bowel disease.

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Akerstrom G (1989). Surgical treatment of patients with the carcinoid syndrome, *Acta Oncol*

Alkan S, Karcher DS, Newman MA, Cohen P (1996). Regression of salivary gland MALT

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Aomatsu T, Yoden A, Matsumoto K, Kimura E, Inoue K, Andoh A, Tamai H (2011). Fecal

Aranha GV, Greenle HB (1980). Surgical management of carcinoid tumors of the

classification of non Hodgkin's lymphoma. The non Hodgkin's lymphoma

calprotectin is a useful marker for disease activity in pediatric patients with

**4. References** 

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Fig. 9. Mucosal lymphocytes nodule. Glands, well structured, present a reduction of mucus cells. The lamina propria is infiltrated by immunocompetent elements. (20x). 15 cm from the anal verge.

A 6 weeks cycle of Mesalazine (5ASA), 2gr/day was administered to the patient obtaining the induction of remission and then repeated every 2 months for the prevention of recurrences. At present the patient is doing well and a strict clinical serologic follow-up with calprotectin, P-Anca and ASCA is scheduled every 6 months and, yearly, colonoscopy.
