Abdominal mass


 * Associate Editor(s)-In-Chief: John Fani Srour, M.D.

Overview
An abdominal mass is any localized enlargement or swelling in the human abdomen. Depending on its location, the abdominal mass may be caused by an enlarged liver (hepatomegaly), enlarged spleen (splenomegaly), protruding kidney, a pancreatic mass, a retroperitoneal mass (a mass in the posterior of the peritoneum), an abdominal aortic aneurysm, or various tumours, such as those caused by abdominal carcinomatosis and omental metastasis. The treatments depend on the cause, and may range from watchful waiting to radical surgery.

Features
Many abdominal masses are discovered incidentally during routine physical examination. When they present symptomatically, abdominal masses are most frequently associated with pain or digestive problems. However, depending on the cause, masses may be associated with other signs and symptoms, such as jaundice or bowel obstruction.

Diagnosis
The first steps in diagnosis are a medical history and physical examination. Important clues during history include weight loss, diarrhea and abdominal pain.

During physical examination, the clinician must identify the location of the mass, as well as characterize its location (usually specified in terms of quadrants). The mass should be assessed for whether it is rigid or mobile. It should also be characterized for pulse or peristalsis, as these would help in further identifying the mass.

Routine blood tests are usually the next step in diagnosis after a thorough medical history and physical examination. They should include a full blood count, blood urea nitrogen (BUN), creatinine, and liver function tests such as albumin, international normalized ratio (INR), partial thromboplastin time (PTT), serum amylase and total bilirubin (TBIL). If late-stage liver disease is suspected, then a serum glucose may be appropriate.

Complete Differential Diagnosis of Causes of Abdominal Mass
In alphabetical order.


 * Abdominal Aortic Aneurysm
 * Abscess
 * Actinomyces
 * Acute pancreatitis
 * Adrenal tumor
 * Alveolar hydatid disease (parasite mass, most commonly involving the liver)
 * Amyloidosis (hepatomegaly and splenomegaly)
 * Aneurysms
 * Ascites (localized ascites)
 * Autoimmune pancreatitis (inflammatory mass)
 * Bezoar
 * Biliary atresia
 * Bladder distention
 * Blind loop syndrome ( the mass is the loop of the bowel)
 * Bowel obstruction (the mass is a loop of the obstructed bowel)
 * Brenner tumor (ovarian tumor)
 * Burkitt's lymphoma
 * Carcinoid tumours
 * Cholangiocarcinoma
 * Cholecystitis ( inflammatory mass, or abscess)
 * Choledochal cyst
 * Cholelithiasis ( a stone filled gallbladder can produces a painless right-upper-quadrant mass)
 * Choriocarcinoma
 * Chronic myelogenous leukemia (splenomegaly)
 * Cirrhosis ( the liver itself or one significantly enlarged nodule) C66
 * Colonic diverticulitis (inflammatory mass or peridiverticular abscess)
 * Colorectal cancer
 * Congenital megacolon (Hirschsprung's disease)
 * Constipation (fecal mass or dilated colon)
 * Crohn's disease ( abscess, loop of obstructed bowel, or inflammatory mass with or with out fistula)
 * Cryptorchidism
 * Dermoid cyst
 * Desmoplastic small round cell tumor ( soft tissue sarcoma, usually multiple abdominal masses)
 * Distal intestinal obstruction syndrome ( in patients with cystic fibrosis or pancreatic enzymes insufficiency)
 * Ectopic pregnancy
 * Endodermal sinus tumor
 * Endometriosis
 * Entamoeba histolytica (hepatomegaly and splenomegaly)
 * Eosinophilic gastroenteritis ( rare presentation as an obstructing caecal mass)
 * Extramedullary hematopoiesis (splenomegaly)
 * Gallbladder benign tumors
 * Gallbladder cancer
 * Gallbladder empyema
 * Gastrointestinal stromal tumor
 * Gastroschisis ( other names paraomphalocele, laparoschisis, or abdominoschisis)
 * Germ cell tumor
 * Hamartoma
 * Hemangioendothelioma
 * Hemangiopericytoma
 * Hepatic adenoma
 * Hepatoblastoma
 * Hepatomegaly
 * 4-hydroxyphenylpyruvate hydroxylase deficiency
 * Alpha-L-iduronidase deficiency (Hurler syndrome)
 * Alpha-L-iduronidase deficiency (Hurler-Scheie syndrome)
 * Alpha-mannosidase deficiency
 * Amyloidosis
 * Apolipoprotein C-II deficiency
 * Arginosuccinate synthetase deficiency
 * Arginosuccinic aciduria
 * Autoimmune lymphoproliferative syndrome type 1
 * Autoimmune lymphoproliferative syndrome type 2
 * Berardinelli lipodystrophy syndrome
 * Carnitine palmitoyltransferase 1 deficiency
 * Castleman disease
 * Cerebrohepatorenal syndrome
 * Chanarin-Dorfman disease
 * Chediak-Higashi disease
 * Cholesterol ester storage disease
 * Coproporphyria, hereditary
 * Cystic fibrosis
 * Dibasic aminoaciduria type 2
 * Extramedullary haemopoiesis
 * Familial alphalipoprotein deficiency
 * Familial histiocytic reticulosis
 * Familial hypertriglyceridaemia
 * Fanconi-Bickel syndrome
 * Farber lipogranulomatosis
 * Fructose-1, 6-diphosphatase deficiency
 * Fructose-1-phosphate aldolase deficiency
 * Fucosidosis
 * Fumarase deficiency
 * Galactose epimerase deficiency
 * Galactose-1-phosphate uridyltransferase deficiency
 * Gangliosidosis GM1, type 1
 * Gangliosidosis GM1, type 3
 * Gangliosidosis GM3
 * Gaucher disease
 * Geleophysic dysplasia
 * Glutaric acidemia type 2
 * Glycine N-methyltransferase deficiency
 * Glycogenosis type 1a
 * Glycogenosis type 1b
 * Glycogenosis type 2
 * Glycogenosis type 3
 * Glycogenosis type 6
 * Glycogenosis type 8
 * Haemochromatosis
 * Hepatic hemangioma
 * Hepatic venoocclusive disease with immunodeficiency ]]
 * Hepatocellular jaundice]]
 * I-cell disease
 * Iduronate-2-sulfatase deficiency
 * Iminodipeptiduria
 * Lipoprotein lipase deficiency
 * Liver granuloma
 * Long chain hydroxyacyl-CoA dehydrogenase deficiency
 * Long-chain Acyl-CoA dehydrogenase deficiency
 * Mucopolysaccharidosis type IVB
 * Mucopolysaccharidosis VI
 * Myelofibrosis
 * Niemann-Pick disease type B
 * Niemann-Pick Disease, Type C
 * Norrbottnian Gaucher disease
 * Osteopetrosis (malignant)
 * Osteopetrosis (malignant)
 * Plasma membrane carnitine transporter deficiency
 * POEMS syndrome
 * Polycystic kidney disease
 * Polycystic liver disease
 * Riedel lobe of liver
 * Salla disease
 * Sandhoff disease
 * Sanfilippo disease
 * Sickle cell crisis
 * Sphingomyelinase deficiency
 * Syphilis, congenital
 * Toxoplasma, congenital
 * Very long-chain acyl-CoA dehydrogenase deficiency
 * Visceral larva migrans
 * Wilson disease
 * Wolcott-Rallison syndrome
 * Zimmermann-Laband syndrome
 * Hernia
 * Hirschsprung's disease (congenital megacolon)
 * Hodgkin's lymphoma
 * Hydatid cyst
 * Hydronephrosis
 * Intususception of the intestine
 * kala-azar or Leishmaniasis (splenomegaly)
 * Kaposi sarcoma
 * Kidney cancer (including renal cell carcinoma)
 * Krukenberg tumor (secondary ovarian malignancy whose primary site arose in the gastrointestinal tract)
 * Large bowel obstruction
 * Leiomyoma
 * Liposarcoma(retroperitoneal)
 * Liver abscess
 * Liver cancer, metastatic
 * Liver cancer, primary (hepatocellular carcinoma)
 * Liver granuloma
 * Lymphogranuloma venereum
 * Meigs syndrome (ovarian tumor)
 * Mesenteric cyst
 * Mesothelioma ( abdominal )
 * Mucosal-associated lymphoid tissue lymphoma (MALTOMA)
 * Mycobacterium tuberculosis (hepatomegaly and splenomegaly)
 * Nephroblastoma
 * Neurilemmoma
 * Neuroblastoma
 * Neuroendocrine tumor
 * Neurofibromatosis
 * Non-Hodgkin lymphoma
 * Obesity ( subcutaneous fat mass)
 * Oesophagostomiasis ( a parasitic intestinal helminth that develops in the colonic wall, causing pus-filled granulomas)
 * Ogilvie's Syndrome (dilated loop of bowels)
 * Oncocytoma (of the kidney)
 * Ovarian cancer
 * Ovarian cyst
 * Palpable gallbladder (Courvoisier's sign)
 * Pancreatic abscess
 * Pancreatic cancer
 * Pancreatic islet cell tumors
 * Pancreatic pseudocyst
 * Pelvic inflammatory disease (abscess)
 * Pelvic kidney
 * Peritoneal adhesions
 * Phaeochromocytoma
 * Plexosarcoma
 * Polycystic kidney disease
 * Pregnancy
 * Prune belly syndrome
 * Pseudomyxoma peritonei
 * Pyloric stenosis
 * Rectus sheath hematoma
 * Renal cell carcinoma
 * Renal oncocytoma
 * Renal transplantation (the mass is the transplanted kidney)
 * Rhabdoid tumor
 * Riedel lobe of liver (sessile accessory lobe of the liver, a normal variant)
 * Sacrococcygeal teratoma
 * Sarcoidosis ( granulomatus mass, hepatomegaly, or splenomegaly
 * Sickle cell crisis (abdominal / sequestration)
 * Sister Mary Joseph nodule
 * Small bowel lymphoma
 * Small bowel obstruction
 * Small intestine cancer
 * Spleen lymphoma
 * Splenomegaly
 * Acanthocheilonemiasis
 * Adult T cell leukemia
 * Alpha-L-iduronidase deficiency (Hurler syndrome)
 * Alpha-L-iduronidase deficiency (Hurler-Scheie syndrome)
 * Alpha-mannosidase deficiency
 * Amyloidosis
 * Angioimmunoblastic lymphadenopathy with dysproteinaemia
 * Apolipoprotein C-II deficiency
 * Autoimmune lymphoproliferative syndrome type 1
 * Autoimmune lymphoproliferative syndrome type 2
 * Babesiosis
 * Bartonellosis
 * Beta thalassaemia (heterozygous)
 * Brucellosis
 * Cardiac failure, right sided
 * Castleman disease
 * Cat scratch fever
 * Chanarin-Dorfman disease
 * Chediak-Higashi disease
 * Cholesterol ester storage disease
 * Chronic lymphocytic leukaemia
 * Chronic myeloid leukaemia
 * Common variable hypogammaglobulinaemia
 * Congenital dyserythropoietic anaemia type 1
 * Congenital erythropoeitic porphyria
 * Coproporphyria, hereditary
 * Cruveilhier-Baumgarten syndrome
 * Dengue
 * Endocarditis
 * Epstein-Barr virus
 * Extramedullary haemopoiesis
 * Familial alphalipoprotein deficiency
 * Familial histiocytic reticulosis
 * Familial hypertriglyceridaemia
 * Farber lipogranulomatosis
 * Filgrastim
 * Fucosidosis
 * Fumarase deficiency
 * Galactose epimerase deficiency
 * Galactose-1-phosphate uridyltransferase deficiency
 * Gamma heavy chain disease
 * Gangliosidosis GM1, type 1
 * Gangliosidosis GM1, type 3
 * Gangliosidosis GM3
 * Gaucher disease
 * Geleophysic dysplasia
 * Glucose phosphate isomerase deficiency
 * Glycogenosis type 4
 * Granulocyte colony stimulating factor
 * Haemochromatosis
 * Haemoglobin C disease
 * Haemoglobin E disease
 * Haemoglobin SC disease
 * Haemolytic disease of the newborn
 * Hairy cell leukaemia
 * Hepatic portal vein obstruction
 * Hepatic vein thrombosis
 * Hepatitis B
 * Hereditary spherocytosis
 * Histiocytosis X
 * Hodgkin lymphoma
 * I-cell disease
 * Iduronate-2-sulfatase deficiency
 * Iminodipeptiduria
 * Infectious mononucleosis
 * Juvenile chronic arthritis
 * Kartagener syndrome
 * Long chain hydroxyacyl-CoA dehydrogenase deficiency
 * Macrophage activation syndrome
 * Malaria (benign quartan)
 * Malaria (benign tertian)
 * Malaria (malignant tertian)
 * Mastocytosis
 * McLeod phenotype
 * Mevalonate kinase deficiency
 * Mixed essential cryoglobulinaemia
 * mu chain disease
 * Mucopolysaccharidosis VI
 * Myelofibrosis
 * Myeloma
 * Neutrophilia, hereditary
 * Niemann-Pick disease type B
 * Niemann-Pick Disease, Type C
 * Non-Hodgkin lymphoma
 * Norrbottnian Gaucher disease
 * Osteopetrosis (malignant)
 * Paragonimiasis
 * Polycythaemia rubra vera
 * Primary autoimmune haemolytic anaemia
 * Primary biliary cirrhosis
 * Primary thrombocythemia, acquired
 * Psittacosis
 * Relapsing fever
 * Rickettsiae
 * Rubella
 * Salla disease
 * Sandhoff disease
 * Sanfilippo disease
 * Sarcoidosis
 * Schistosoma haematobium
 * Schistosoma mansoni
 * Sea blue histiocytosis
 * Serum sickness
 * Sickle cell disease
 * Sleeping sickness (East African)
 * Sleeping sickness (West African)
 * Sphingomyelinase deficiency
 * Still disease, adult-onset
 * Still Disease, Juvenile-Onset
 * Syphilis, congenital
 * Systemic lupus erythematosus
 * Tertiary syphilis
 * Toxocariasis
 * Toxoplasma
 * Toxoplasma, congenital
 * Trench fever
 * Typhus fever
 * Tyrosinaemia type 1
 * Visceral larva migrans
 * Visceral leishmaniasis
 * Vitamin B12 deficiency
 * Waldenström macroglobulinaemia
 * Whipple disease
 * Zimmermann-Laband syndrome
 * Splenosis (autotransplantation of splenic tissues, usually after splenic rupture)
 * Stomach cancer
 * Syphilis(congenital)
 * Tertiary syphilis (mass, hepatomegaly, and splenomegaly)
 * Toxic megacolon
 * Toxoplasmosis(congenital)
 * Transitional cell carcinoma (bladder)
 * Urachal cyst (a sinus remaining from the allantosis during embryogenesis)
 * Ureteropelvic junction obstruction (pediatric hydronephrosis and palpable kidneys)
 * Urine retention (distended bladder)
 * Uterine enlargement
 * Uterine leiomyoma (fibroids)
 * Varicocele
 * Vermiform appendix
 * Visceral larva migrans
 * Volvulus (twisted piece of the gastrointestinal tract)
 * Wandering spleen
 * Wilm's tumor (pediatric renal tumor)
 * Yersinia enterocolitica (inflammatory mass, lymphoid mass, or Intususception of intestine)

Physical Examination

 * Associated symptoms:
 * Rectal bleeding
 * Weight change
 * Urinary symptoms
 * Fever
 * Changes in bowel habits

Abdomen

 * Examine abdomen for areas of tenderness

Other

 * Examine pelvis for areas of tenderness

Laboratory Findings

 * Blood urea nitrogen (BUN)/creatinine
 * Complete blood count (CBC)
 * LFTs (liver function tests)
 * Urinalysis
 * Beta-human chorionic gonadotrophin

Electrolyte and Biomarker Studies

 * Electrolytes
 * Tumor markers (if concern is malignancy)
 * Toxicology screen
 * Blood culture (if concern is infection)

X Ray

 * KUB (kidneys, ureters, bladder) x-rays could possibly reveal free intraperitoneal air, constipation or obstruction.

MRI and CT

 * Abdominal CT with oral IV contrast will evaluate for bowel pathology, abscess, and hepatosplenomegaly

Other Diagnostic Studies

 * Laparoscopy of the intra-abdominal cavity allows for direct visualization
 * Colonoscopy helps in the diagnosis of bowel pathology
 * Paracentesis with fluid evaluation.

Treatment

 * Immediately treat life-threatening causes (such as abdominal aortic aneurysms).
 * Organomegaly typically resolves once the underlying etiology is treated.

Acute Pharmacotherapies

 * Ogilvie's syndrome responds to decompression by IV neostigmine or by a rectal tube
 * Constipation is usually treated with laxatives, increased dietary fiber and fluids, enemas.
 * Manual disimpaction is reserved for fecal impaction.
 * Stop use of offending medications.
 * Masses caused by infections require antibiotics (and possible surgery)

Surgery and Device Based Therapy

 * Several benign and malignant masses require surgical intervention
 * Hirschsprung's disease often requires surgery.

Additional Resources

 * MedlinePlus medical encyclopedia: Abdominal mass - An informative primer on abdominal masses and their common causes.
 * First Principles of Gastroenterology: Abdominal Mass - This chapter discusses the basic approach to abdominal masses.

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