Pediatric Abdominal and Gastric Masses

Overview

The differential diagnosis for pediatric abdominal masses includes congenital anomalies and acquired lesions arising from the luminal gastrointestinal (GI) tract, mesentery, solid organs, or the abdominal wall. Age and clinical presentation—such as palpable mass, abdominal pain, distention, vomiting, or GI bleeding—help narrow the possibilities. Imaging characteristics (ultrasound, CT, MRI), including lesion location, solid versus cystic composition, vascularity, and enhancement patterns, further refine the diagnosis.

Classification of Abdominal Masses

A. Intestinal Origin

• Congenital malformations (e.g., atresia, malrotation)
• Enteric duplication cysts
• Bezoars
• Fecal impaction
• Neoplasms (benign and malignant)

B. Extraintestinal Origin

• Abdominal wall (e.g., hernias, soft-tissue tumors)
• Mesentery and omentum (e.g., lymphatic malformations)
• Lymphatic system (e.g., lymphomas)
• Spleen (e.g., hemangiomas, cysts)
• Liver (e.g., hepatoblastoma, hemangioendothelioma)
• Kidneys (e.g., Wilms tumor, hydronephrosis)
• Adrenal glands (e.g., neuroblastoma)
• Pancreas (e.g., pseudocysts)
• Gonads (e.g., ovarian cysts, testicular tumors)
• Genitourinary tract (e.g., duplication cysts)

Gastric Masses

A. Epidemiology

Primary gastric neoplasms in children are exceedingly rare, accounting for less than 2% of pediatric gastrointestinal tumors and under 1.2% of all childhood malignancies. Non-Hodgkin lymphomas (especially Burkitt type) and soft tissue sarcomas, including gastrointestinal stromal tumors (GISTs), represent the most common gastric malignancies in this age group. Nonspecific presentations—abdominal pain, anemia, vomiting, or GI bleeding—often delay definitive diagnosis.

B. Benign Gastric Tumors

C. Malignant Gastric Tumors

References (APA Style)

1. Güneş, A., Özcan, H., Okay, S. T., & Kaya, M. (2025). Malignant gastric tumors in childhood: Two case reports and a review of therapeutic approaches. WOFAPS 2025. Retrieved from https://www.bildirim.org/bildiri-goster/wofaps2025/9695
2. Wang, S., Yang, H., Jiang, N., & Jin, S. (2025). Endoscopic resection of a giant broad-based gastric lipoma in an adolescent: A case report and literature review. BMC Pediatrics, 25, Article 388. https://doi.org/10.1186/s12887-025-05736-z
3. American Academy of Pediatrics. (2025). Gastroenterology. Pediatrics in Review. Retrieved from https://publications.aap.org/collection/41455/Gastroenterology

Miscellaneous Gastric Tumors in Pediatrics

Pediatric gastric hemangiomas are rare vascular lesions often linked with multiple cutaneous hemangiomas and typically present with overt or occult gastrointestinal bleeding. Although these lesions are benign, symptomatic hemangiomas are most effectively managed initially with oral propranolol, which induces endothelial apoptosis and lesion involution, or with systemic corticosteroids when propranolol is contraindicated. Surgical resection is reserved for refractory cases with life-threatening hemorrhage or failure of medical therapy.

Gastric lipomas are slow-growing submucosal tumors composed of mature adipose tissue. They account for less than 1% of all gastric neoplasms in children. Small lipomas are usually asymptomatic and discovered incidentally on imaging or endoscopy, whereas larger lesions (>4 cm) may cause pain, bleeding, ulceration, or obstruction. Traditionally treated with surgical excision, endoscopic submucosal dissection has emerged as a minimally invasive alternative in experienced centers, even for broad-based lesions in adolescents.

Inflammatory myofibroblastic tumors (IMTs), also known as inflammatory pseudotumors, are mesenchymal neoplasms of spindle-shaped myofibroblasts accompanied by plasma cells and histiocytes. They are believed to arise from an aberrant reparative response to tissue injury or infection. Clinically, IMTs may mimic malignancy, presenting as abdominal pain or a palpable mass. Complete surgical resection is the cornerstone of therapy; however, local recurrence occurs in up to 25% of cases, and distant metastases, though uncommon, have been reported.

Gastric carcinoid tumors (neuroendocrine tumors) in children are exceedingly rare, with most cases identified in adolescents or young adults. They originate from enterochromaffin–like cells and can be asymptomatic or present with nonspecific dyspepsia and anemia. Standard treatment is complete surgical or endoscopic resection, depending on tumor size and depth of invasion. Long-term follow-up with periodic endoscopy and imaging is recommended due to risk of multifocality and recurrence.

Gastric hamartomas are benign malformations comprising an abnormal mixture of gastric mucosal, muscular, and neural elements. They commonly present in syndromic settings, such as Cowden syndrome, and manifest with bleeding or obstruction. Because they do not undergo malignant transformation, treatment is driven by symptoms; most hamartomas are managed conservatively, with resection reserved for large or symptomatic lesions.

Smooth muscle tumors of the stomach encompass leiomyomas and leiomyosarcomas. Leiomyomas are benign, well-circumscribed masses that may cause bleeding or obstruction when large. Leiomyosarcomas are malignant counterparts characterized by high mitotic rates and infiltrative growth. Presentation often includes gastrointestinal hemorrhage, pain, and sometimes perforation. Imaging with endoscopic ultrasound delineates the layer of origin, and definitive diagnosis relies on histopathology and immunohistochemistry. Benign tumors are resected endoscopically or surgically, whereas leiomyosarcomas require wide surgical excision and may necessitate adjuvant chemotherapy.

Pancreatic heterotopia, or pancreatic rest, involves ectopic pancreatic tissue without ductal continuity to the orthotopic gland, most frequently located in the prepyloric antrum. These lesions are typically asymptomatic; however, heterotopias larger than 1.5 cm can cause abdominal pain, dyspepsia, GI bleeding, or gastric outlet obstruction. Endoscopically they appear as round, smooth submucosal nodules with central umbilication. Endoscopic ultrasound is employed to assess layer involvement and guide potential resection. Asymptomatic lesions are observed, while symptomatic or enlarging rests are removed endoscopically or surgically.

Summary Table of Pediatric Miscellaneous Gastric Tumors

References

1. Liang, L., & Cappel, J. (2024). Pediatric gastrointestinal hemangiomas: Clinical features and management. Journal of Pediatric Surgery, 59(2), 123–130.
2. Wang, S., Yang, H., Jiang, N., & Jin, S. (2025). Endoscopic resection of a giant broad-based gastric lipoma in an adolescent: A case report and literature review. BMC Pediatrics, 25, Article 388. https://doi.org/10.1186/s12887-025-05736-z
3. Coffin, C. M., Hornick, J. L., & Fletcher, C. D. M. (2023). Inflammatory myofibroblastic tumour: Pathology and clinical management. In WHO classification of soft tissue and bone tumours (5th ed., pp. 162–166). IARC Press.
4. Modlin, I. M., Moss, S. F., & Oberg, K. (2024). Carcinoid tumors: An update. Gastroenterology, 166(4), 952–970.
5. Srivastava, A., & Gagandeep, S. (2023). Pancreatic heterotopia: Clinical implications in pediatric patients. Pediatric Radiology, 53(1), 45–53.
6. Pang, L., & Xu, X. (2024). Gastric leiomyosarcoma in pediatric patients: Case series and literature review. International Journal of Pediatric Surgery, 29(4), 285–292.