Organomegaly is the abnormal enlargement of organs. For example, clitoromegaly is the enlargement of the clitoris, and cardiomegaly is enlargement of the heart. Visceromegaly is the enlargement of abdominal organs.[1] Examples of visceromegaly are enlarged liver (hepatomegaly), spleen (splenomegaly), stomach, kidneys, and pancreas.
Definitions for various organsEditValues refer to adults unless otherwise specified.
| Organ | Term for enlargement | Cutoff for definition |
|---|
| Abdominal aorta | Ectasia or mild dilation | >2.0 cm and <3.0 cm[2] |
| Abdominal aortic aneurysm | - Moderate AAA: 3.0–5.0 cm[2]
- Large or severe AAA: >5.0[2] or 5.5.[3] cm
|
| Common bile duct | Dilatation | - Mild dilatation:[4] 8–12 mm
- Moderate dilatation:[4] 12–16 mm
- Severe dilatation:[4] 16–20 mm
- Extremely severe dilatation:[4] >20 mm
|
| Gallbladder | Wall thickening | 3 mm wall thickness[5] |
| Hydrops | Greater than 5 cm transverse dimension[6] |
| Heart | Cardiomegaly | - Medical imaging: Indicated by cardiothoracic ratio over 0.5.[7]
- Autopsy: Cardiomegaly has been suggested when the heart weighs more than >399 grams in women and >449 grams in men.[8]
|
| Large intestine | Dilation | Upper limit of normal range of diameter:[9] - 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 thickening | Wall thickness 5 mm[10] |
| Kidneys | Enlargement | - Medical imaging: Length >13 cm in females or >14 cm in males.[11]
- Autopsy:
| Sex | Upper limit of standard reference range | | Right kidney | Left kidney | | Men[12] | 160 g (5.6 oz) | 175 g (6.2 oz) | | Women[13] | 175 g (6.2 oz) | 190 g (6.7 oz) |
|
| Liver | Hepatomegaly | - Medical imaging: Longitudinal axis > 15.5 cm at the hepatic midline, or > 16.0 cm at the midclavicular line[14]
- Autopsy: Weight over upper limit of standard reference range, of 1,860 g (4.10 lb) in men[12] and 1,770 g (3.90 lb) in women.[13]
|
| Lymph nodes | Lymphadenopathy | Generally 10 mm[15][16] (see Lymphadenopathy) for detailed values) |
| Renal pelvis | Part 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.[17]
- Adults: cutoff values defined differently by different sources, with anteroposterior diameters ranging between 10 and 20 mm.[18] About 13% of normal healthy adults have a transverse pelvic diameter of over 10 mm.[19]
|
| Prostate | Prostatomegaly | Volume over 30 cm3. |
| Pulmonary artery | Dilation | >29 mm[20] |
| Small intestine | Dilation | - 2.5 cm on CT scans[21][22]
- Mild: 2.5–2.9 cm[23]
- Moderate: 3-4 cm[23]
- Severe: >4 cm[23]
- 3 cm on abdominal X-rays[21][24] (Projectional radiography confers a geometric magnification compared to CT[25])
|
| Wall thickening | 3–5 mm[26] |
| Spleen | Splenomegaly | - Medical imaging: Largest dimension of over 11 cm,[27][28] or craniocaudal height of 13[29] cm.
- Moderate splenomegaly: the largest dimension is between 11–20 cm[27]
- Severe splenomegaly: the largest dimension is greater than 20 cm[27]
- Autopsy: Weight over upper limit of standard reference range, of 230 g (8.1 oz)[12][13]
|
| Thoracic aorta | Dilation | Diameters: Upper limits of standard reference range: - 3.3 cm in small young individuals[31]
- 4.3 cm among large elderly individuals.[31]
- Descending thoracic aorta,
- 2.3 cm among small young individuals[31]
- 3.2 cm among large elderly individuals.[31]
|
| Thoracic aortic aneurysm | Diameter:- > 4.5 cm (US)[30]
- > 4.0 cm (Korea)[32]
|
| Testis | Enlargement | 5 cm (long axis) x 3 cm (short axis)[33] |
| Tonsil | Enlarged tonsil | 2.5 cm in length, 2.0 cm in width and 1.2 cm in thickness.[34] |
| Ureter | Megaureter | 6[35] or 7[36] mm |
| Urinary bladder | Wall thickening | 3–5 mm thick, and < 3 mm when well distended.[37] |