Splenomegaly

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Splenomegaly
CT scan in a patient with chronic lymphocytic leukemia, showing splenomegaly. Yellow arrows point at the spleen.
SpecialtyGeneral surgery

Splenomegaly is an enlargement of the

lymphomas. Thus, the finding of an enlarged spleen, along with caput medusae, is an important sign of portal hypertension.[2]

Definition

Maximum dimension of the spleen on abdominal ultrasonography.

The standard system for classifying splenomegaly on radiography is:[3][4]

  • Normal (not splenomegaly): the largest dimension is less than 11 cm
  • Moderate splenomegaly: the largest dimension is between 11 and 20 cm
  • Severe splenomegaly: the largest dimension is greater than 20 cm

Also, a

cutoff of a craniocaudal height of 13 cm is also used to define splenomegaly.[5]
In addition, individual intervals have been established:

90% confidence interval of maximum spleen length by abdominal ultrasonography by height of the person[6]
Height Spleen length
Women Men
155 – 159 cm 6.4 – 12 cm
160 – 164 cm 7.4 - 12.2 cm 8.9 - 11.3 cm
165 – 169 cm 7.5 – 11.9 cm 8.5 – 12.5 cm
170 – 174 cm 8.3 – 13.0 cm 8.6 – 13.1 cm
175 – 179 cm 8.1 – 12.3 cm 8.6 – 13.4 cm
180 – 184 cm 9.3 – 13.4 cm
185 – 189 cm 9.3 – 13.6 cm
190 – 194 cm 9.7 – 14.3 cm
195 – 199 cm 10.2 – 14.4 cm
Age Cutoff[7]
3 months 6.0 cm
6 months 6.5 cm
12 months 7.0 cm
2 years 8.0 cm
4 years 9.0
6 years 9.5 cm
8 years 10.0 cm
10 years 11.0 cm
12 years 11.5 cm
15 years
  • 12.0 cm
    for girls
  • 13.0 cm
    for boys

For children, the cutoffs for splenomegaly are given in this table, when measuring the greatest length of the spleen between its dome and its tip, in the coronal plane through its hilum while breathing quietly.[7]

At autopsy, splenomegaly can be defined as a spleen weight above the upper limit of the standard reference range of 230 g (8.1 oz).[8][9]

Splenomegaly refers strictly to spleen enlargement, and is distinct from hypersplenism, which connotes overactive function by a spleen of any size. Splenomegaly and hypersplenism should not be confused. Each may be found separately, or they may coexist. Clinically, if a spleen is palpable (felt via external examination), it means it is enlarged as it has to undergo at least twofold enlargement to become palpable. However, the tip of the spleen may be palpable in a newborn baby up to three months of age.[10]

Signs and symptoms

pleuritic pain when stomach, bladder or bowels are full, back pain, early satiety due to splenic encroachment, or the symptoms of anemia due to accompanying cytopenia
.

Signs of splenomegaly may include a palpable left upper quadrant abdominal mass or splenic rub. It can be detected on physical examination by using Castell's sign, Traube's space percussion or Nixon's sign, but an ultrasound can be used to confirm diagnosis. In patients where the likelihood of splenomegaly is high, the physical exam is not sufficiently sensitive to detect it; abdominal imaging is indicated in such patients.[11]

In cases of infectious mononucleosis splenomegaly is a common symptom and health care providers may consider using abdominal ultrasonography to get insight into a person's condition.[12] However, because spleen size varies greatly, ultrasonography is not a valid technique for assessing spleen enlargement and should not be used in typical circumstances or to make routine decisions about fitness for playing sports.[12]

Causes

The most common causes of splenomegaly in developed countries are

hematological malignancy and portal hypertension (most commonly secondary to liver disease, and sarcoidosis). Splenomegaly may also come from bacterial infections, such as syphilis or an infection of the heart's inner lining (endocarditis).[13] Splenomegaly also occurs in mammals parasitized by Cuterebra fontinella.[14]

The possible causes of moderate splenomegaly (spleen <1000 g) are many, and include:

Splenomegaly grouped on the basis of the pathogenic mechanism
Increased function Abnormal blood flow Infiltration
Removal of defective RBCs

Immune hyperplasia

Response to infection (viral, bacterial, fungal, parasitic)

Disordered immunoregulation

Extramedullary hematopoiesis

  • myelofibrosis
  • marrow infiltration by
    leukemias
  • marrow damage by
    toxins
Organ Failure

Vascular

Infections

Metabolic diseases

Benign and malignant "infiltrations"

Normal spleen (in green)

The causes of massive splenomegaly (spleen >1000 g) are

Pathophysiology

Splenomegaly can be classified based on its pathophysiologic mechanism:

[1]

Diagnosis

Abdominal CT is the most accurate. The spleen needs to be 2–3 times larger than normal to be palpable below the costal margin in physical examination.

Treatment

If the splenomegaly underlies hypersplenism, a splenectomy is indicated and will correct the hypersplenism. However, the underlying cause of the hypersplenism will most likely remain; consequently, a thorough diagnostic workup is still indicated, as, leukemia, lymphoma and other serious disorders can cause hypersplenism and splenomegaly. After splenectomy, however, patients have an increased risk for infectious diseases.

Patients undergoing splenectomy should be

prophylactic antibiotics
may be given in certain cases.

As an adaptation

An enlarged spleen may be an inherited, adaptive trait selected in populations that need extra oxygen carry capacity such as deep sea divers.[21][22]

See also

References

  1. ^
    PMID 28613657
    , retrieved 2019-02-26
  2. .
  3. ^ Neetu Radhakrishnan. "Splenomegaly". Medscape. Retrieved February 16, 2018. Updated Apr. 2012 (referring the classification system to Poulin et al.
  4. .
  5. .
  6. .
  7. ^ .
  8. .
  9. .
  10. .
  11. ^
    ABIM Foundation
    , American Medical Society for Sports Medicine, retrieved 29 July 2014, which cites
  12. .
  13. ^ Durden LA (1995). "Bot Fly (Cuterebra fontinella fontinella) Parasitism of Cotton Mice (Peromyscus gossypinus) on St. Catherines Island, Georgia". The Journal of Parasitology. 81 (5): 787–790.
    PMID 7472877
    .
  14. .
  15. .
  16. ^ Neufeld EF, Muenzer J (1995). "The mucopolysaccharidoses". In Scriver CR, Beaudet AL, Sly WS, Valle D (eds.). The metabolic and molecular bases of inherited disease.7th ed. Vol. 2. McGraw-Hill, New York. pp. 2465–94.
  17. PMID 16999722
    .
  18. .
  19. .
  20. ^ Rappaport, Lisa (19 April 2018). "Large spleen helps explain deep-diving skills of Southeast Asian 'sea nomads'". Reuters. Retrieved 20 April 2018.
  21. PMID 29677510
    .

External links