organomegaly organomegaly organomegaly is the abnormal enlargement of organs. for example, cardiomegaly is enlargement of the heart. visceromegaly is the enlargement of abdominal organs. examples of visceromegaly are enlarged liver (hepatomegaly), spleen (splenomegaly), stomach, kidneys, and pancreas. definitions for various organs values refer to adults unless otherwise specified. organterm for enlargementcutoff for definition abdominal aortaectasia or mild dilation >2.0 cm and <3.0 cm abdominal aortic aneurysm moderate aaa: 3.0–5.0 cm large or severe aaa: >5.0 or 5.5. cm common bile ductdilatation mild dilatation: 8–12 mm moderate dilatation: 12–16 mm severe dilatation: 16–20 mm extremely severe dilatation: >20 mm gallbladderwall thickening3 mm wall thickness hydropsgreater than 5 cm transverse dimension heartcardiomegaly medical imaging: indicated by cardiothoracic ratio over 0.5. autopsy: cardiomegaly has been suggested when the heart weighs more than >399 grams in women and >449 grams in men. large intestinedilation upper limit of normal range of diameter: cecum: 10.5 cm ascending colon: 7.0 cm transverse colon: 6.5 cm descending colon and sigmoid colon: 6.8 cm rectum near rectal/sigmoid junction: 7.5 cm wall thickeningwall thickness 5 mm kidneysenlargement medical imaging: length >13 cm in females or >14 cm in males. autopsy: sexupper limit of standard reference range right kidneyleft kidney men160 g (5.6 oz)175 g (6.2 oz) women175 g (6.2 oz)190 g (6.7 oz) liverhepatomegaly medical imaging: longitudinal axis > 15.5 cm at the hepatic midline, or > 16.0 cm at the midclavicular line autopsy: weight over upper limit of standard reference range, of 1,860 g (4.10 lb) in men and 1,770 g (3.90 lb) in women. lymph nodeslymphadenopathygenerally 10 mm (see lymphadenopathy) for detailed values) renal pelvispart of hydronephrosis grading 4 – 20 mm: fetal: anteroposterior diameter of less than 4 mm in fetuses up to 32 weeks of gestational age and 7 mm afterwards. adults: cutoff values defined differently by different sources, with anteroposterior diameters ranging between 10 and 20 mm. about 13% of normal healthy adults have a transverse pelvic diameter of over 10 mm. prostateprostatomegalyvolume over 30 cm3. pulmonary arterydilation>29 mm small intestinedilation 2.5 cm on ct scans mild: 2.5–2.9 cm moderate: 3-4 cm severe: >4 cm 3 cm on abdominal x-rays (projectional radiography confers a geometric magnification compared to ct) wall thickening3–5 mm spleensplenomegaly medical imaging: largest dimension of over 11 cm, or craniocaudal height of 13 cm. moderate splenomegaly: the largest dimension is between 11–20 cm severe splenomegaly: the largest dimension is greater than 20 cm autopsy: weight over upper limit of standard reference range, of 230 g (8.1 oz) thoracic aortadilation diameters: >3.5 cm generally upper limits of standard reference range: ascending aorta: 3.3 cm in small young individuals 4.3 cm among large elderly individuals. descending thoracic aorta, 2.3 cm among small young individuals 3.2 cm among large elderly individuals. thoracic aortic aneurysm diameter: > 4.5 cm (us) > 4.0 cm (korea) testisenlargement5 cm (long axis) x 3 cm (short axis) tonsilenlarged tonsil2.5 cm in length, 2.0 cm in width and 1.2 cm in thickness. uretermegaureter6 or 7 mm urinary bladderwall thickening3–5 mm thick, and < 3 mm when well distended.