Abdominal Mass



A palpable lesion or fullness in the abdominal cavity which may or may not be related to abdominal viscera or a lesion detected on abdominal imaging; the mass may be abdominal or retroperitoneal in origin.


  • Etiologies for abdominal masses are varied, and the differential depends on age and anatomic location.
  • Majority are nonsurgical in nature; may be associated with constipation
  • Approximately 57% of abdominal masses in children are due to organomegaly (hepatomegaly or splenomegaly).
  • Most abdominal masses in infants originate from the kidney and are benign (e.g., hydronephrosis); Wilms tumor is the most common malignant tumor of the kidney seen in childhood.
  • Liver masses account for 5–6% of all pediatric intra-abdominal masses; hepatoblastoma is the most common primary liver tumor in children, often presenting at 1 to 3 years of age.

Risk Factors

  • Certain genetic disorders/syndromes are associated with increased risk of tumor development.
  • Patients with Beckwith-Wiedemann syndrome; Wilms tumor, aniridia, genitourinary anomalies, and mental retardation (WAGR); and Denys-Drash syndrome are at increased risk of Wilms tumor and require regular screening.

General Prevention

Dependent on whether or not the mass or lesion is related to a modifiable factor (e.g., a retained foreign body requires parental or patient counseling for prevention)


Varies based on the type of mass seen


  • Stomach
    • Gastric distension or gastroparesis
    • Duplication
    • Foreign body or bezoar
    • Gastric torsion
    • Gastric tumor (lymphoma, sarcoma)
  • Intestine
    • Feces (constipation)
    • Intestinal distension or toxic megacolon
    • Foreign body
    • Meconium ileus
    • Duplication
    • Volvulus
    • Intussusception
    • Intestinal atresia or stenosis
    • Malrotation
    • Complications of inflammatory bowel disease (abscess, phlegmon)
    • Appendiceal inflammation
    • Meckel diverticulum or abscess
    • Duodenal hematoma (trauma)
    • Lymphoma, adenocarcinoma, GI stromal tumor
    • Carcinoid (appendiceal)
  • Liver
    • Hepatomegaly due to intrinsic liver disease
      • Hepatitis (e.g., infectious, autoimmune)
      • Metabolic or storage disorders (e.g., Wilson disease, glycogen storage disease)
      • Infiltration of liver (cyst, tumors)
      • Biliary obstruction
      • Vascular obstruction/impaired venous congestion (Budd-Chiari syndrome, congestive heart failure)
    • Cystic disease (e.g., Caroli disease)
    • Solid tumor (hepatoblastoma; hepatocellular carcinoma; hepatic adenoma; or other diffuse, systemic, neoplastic process)
    • Vascular tumor (hemangioma or hemangioendothelioma)
    • Other: hamartomas, focal nodular hyperplasia
  • Gallbladder/biliary tract
    • Choledochal cyst
    • Hydrops of gallbladder
    • Obstruction (stone, stricture, trauma)
  • Spleen
    • Congenital cysts
    • Storage disease (e.g., Gaucher, Niemann-Pick)
    • Langerhans cell histiocytosis
    • Leukemia
    • Hematologic (hemolytic disease [e.g., sickle cell] or other RBC disorders [e.g., hereditary spherocytosis])
    • Portal hypertension
    • Wandering spleen
  • Pancreas
    • Congenital cysts
    • Pseudocyst (trauma, pancreatitis)
    • Pancreatoblastoma
    • Neuroendocrine tumors (insulinomas, gastrinomas)
    • Solid and papillary epithelial neoplasms
  • Kidney
    • Hydronephrosis or ureteropelvic obstruction
    • Multicystic dysplastic kidney
    • Polycystic disease
    • Tumor (mesoblastic nephroma, Wilms tumor, renal cell carcinoma)
    • Renal vein thrombosis
    • Cystic nephroma
  • Bladder
    • Bladder distension
    • Neurogenic bladder
  • Adrenal
    • Adrenal hemorrhage
    • Adrenal abscess
    • Neuroblastoma
    • Pheochromocytoma
  • Uterus
    • Pregnancy
    • Hematocolpos
    • Hydrocolpos or hydrometrocolpos
  • Ovary
    • Cysts (dermoid, follicular)
    • Torsion
    • Germ cell tumor
  • Peritoneal
    • Ascites
    • Teratoma
  • Abdominal wall
    • Umbilical/inguinal/ventral hernia
    • Omphalocele/gastroschisis
    • Urachal cyst
    • Trauma (rectus hematoma)
    • Tumor (fibroma, lipoma, rhabdomyosarcoma)
  • Omentum/mesentery
    • Cysts
    • Mesenteric fibromatosis
    • Mesenteric adenitis
  • Other
    • Tumors (liposarcoma, leiomyosarcoma, fibrosarcoma, mesothelioma)
    • Intra-abdominal testicle (torsion)
    • Lymphangioma
    • Fetus in fetu
    • Sacrococcygeal teratoma

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