| Lymphoma (NHL incl. Burkitt) |
Most common malignant SI tumor |
Distal ileum, ileocecal region,
appendix |
Rapid abdominal pain, intussusception, palpable
mass, obstruction, systemic symptoms (fever, weight
loss) |
Systemic multiagent chemotherapy; surgery for
complications; High curability
for Burkitt when treated promptly |
| Adenocarcinoma |
Very rare |
Duodenum (general); ileum in Crohn
disease |
Vague pain, anorexia, weight loss; late GI bleeding
or obstruction |
Surgical resection with lymphadenectomy; adjuvant
therapy individualized; prognosis stage‑dependent |
| GIST |
Rare (~1.4%–2.7% of GISTs in children) |
Stomach > small intestine; small
bowel common in NF1 |
Often occult early; later mass, chronic anemia,
bleeding, obstruction |
Complete en bloc resection; imatinib for KIT/PDGFRA
mutant tumors; pediatric biology differs; Recurrence common |
| MALT / α‑chain disease |
Uncommon; regionally endemic |
Small intestine (variable) |
Malabsorption, protein‑losing enteropathy, chronic
diarrhea, weight loss |
Early disease: antibiotics
(tetracycline±metronidazole); advanced: surgery ±
chemotherapy |
| Enteropathy‑associated T‑cell lymphoma
(EATL) |
Very rare in children |
Small intestine |
Associated with enteropathy in adults; pain,
obstruction, poor prognosis |
Chemotherapy ± surgery; overall guarded prognosis |
| DLBCL |
Uncommon |
Any small intestinal segment |
Aggressive mass, obstruction, bleeding, systemic B
symptoms |
Systemic chemotherapy; prognosis depends on stage
and response |
| Neuroendocrine tumor / Carcinoid |
Rare |
Appendix > stomach > small
intestine > rectum |
Often incidental (appendectomy);
obstruction/bleeding if larger; carcinoid syndrome
rare |
Resection is curative for localized lesions;
appendectomy for <1 cm; right hemicolectomy for
>2 cm or mesoappendix involvement |
| Familial / SDH‑deficient GIST |
Rare; pediatric notable subgroup |
Stomach & small intestine |
Multiple tumors; associations with paragangliomas,
Carney syndromes |
Surgical resection; variable response to TKIs;
lifelong surveillance recommended |
| Leiomyoma / Leiomyosarcoma |
Very rare |
Proximal gut common; distal SI for
leiomyosarcoma |
Bleeding, obstruction, intussusception, perforation |
Local surgical resection; favorable prognosis if
completely resected |
| Neural tumors (ganglioneuroma, schwannoma,
neurofibroma) |
Rare |
Any GI segment |
Polypoid lesions or diffuse involvement; may be
incidental or symptomatic |
Local excision for symptomatic lesions; evaluate for
syndromic associations (NF1, MEN2B, Cowden) |
| Vascular lesions (hemangioma, lymphangioma) |
Rare |
Small intestine, mesentery |
GI bleeding, intussusception, obstruction;
multifocal disease in syndromes |
Surgery or interventional therapy for bleeding;
conservative/supportive care for diffuse disease |
| Lipoma |
Uncommon |
Ileum, duodenum |
Submucosal fatty mass causing
obstruction/intussusception/bleeding |
Local resection or endoscopic polypectomy; excellent
prognosis |