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.
{|class="wikitable"
! Organ !! Term for enlargement !! Cutoff for definition
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|rowspan=2| Abdominal aorta || Ectasia or mild dilation
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>2.0 cm and <3.0 cm
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| Abdominal aortic aneurysm
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- Moderate AAA: 3.0–5.0 cm cm
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| Common bile duct || Dilatation
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- Mild dilatation: 8–12 mm
- Moderate dilatation:
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| Hydrops || Greater than 5 cm transverse dimension
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| Heart || Cardiomegaly ||
- 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.
|-
|rowspan=2| Large intestine || Dilation
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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
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| Wall thickening || Wall thickness 5 mm
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| Kidneys || Enlargement ||
- Medical imaging: Length >13 cm in females or >14 cm in males.
- Autopsy:
{|class="wikitable"
|rowspan=2| Sex ||colspan=2 align="center"| Upper limit of standard reference range
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|align="center"| Right kidney ||align="center"| Left kidney
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| Men
- Autopsy: Weight over upper limit of standard reference range, of in men and in women.
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| Lymph nodes || Lymphadenopathy || Generally 10 mm
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| 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.
- 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.
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| Prostate || Prostatomegaly || Volume over 30 cm<sup>3</sup>.
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| Pulmonary artery || Dilation || >29 mm
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|rowspan=2| Small intestine || Dilation
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- 2.5 cm on CT scans
:*Mild: 2.5–2.9 cm
:*Moderate: 3-4 cm (Projectional radiography confers a geometric magnification compared to CT)
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| Wall thickening || 3–5 mm
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| Spleen || Splenomegaly
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- Medical imaging: Largest dimension of over 11 cm, or craniocaudal height of 13 cm.
:* Moderate splenomegaly: the largest dimension is between 11–20 cm
Upper limits of standard reference range:
- Ascending aorta:
:*3.3 cm in small young individuals
:*4.3 cm among large elderly individuals.
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| Testis || Enlargement || 5 cm (long axis) x 3 cm (short axis)
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| Tonsil || Enlarged tonsil || 2.5 cm in length, 2.0 cm in width and 1.2 cm in thickness.
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| Ureter || Megaureter || 6 or 7 mm
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| Urinary bladder || Wall thickening || 3–5 mm thick, and < 3 mm when well distended.
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