Splenomegaly is an enlargement of the

spleen The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .

. The spleen usually lies in the left upper quadrant (LUQ) of the

human abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

. Splenomegaly is one of the four cardinal signs of ''hypersplenism'' which include: some reduction in number of circulating blood cells affecting granulocytes, erythrocytes or

platelets Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby ini ...

in any combination; a compensatory proliferative response in the bone marrow; and the potential for correction of these abnormalities by splenectomy. Splenomegaly is usually associated with increased workload (such as in hemolytic anemias), which suggests that it is a response to hyperfunction. It is therefore not surprising that splenomegaly is associated with any

disease A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

process that involves abnormal

red blood cell Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...

s being destroyed in the spleen. Other common causes include congestion due to

portal hypertension Portal hypertension is abnormally increased portal venous pressure – blood pressure in the portal vein and its branches, that drain from most of the intestine to the liver. Portal hypertension is defined as a hepatic venous pressure gradient gr ...

and infiltration by leukemias and

lymphomas Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlar ...

. Thus, the finding of an enlarged spleen, along with

caput medusae Caput medusae is the appearance of distended and engorged superficial epigastric veins, which are seen radiating from the umbilicus across the abdomen. The name ''caput medusae'' (Latin for "head of Medusa") originates from the apparent simila ...

, is an important sign of portal hypertension.

Definition

Maximum length of spleen on ultrasonography

The standard system for classifying splenomegaly on

radiography Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeut ...

is: * 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. In addition, individual intervals have been established: 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 The coronal plane (also known as the frontal plane) is an anatomical plane that divides the body into dorsal and ventral sections. It is perpendicular to the sagittal and transverse planes. Details The coronal plane is an example of a longitud ...

through its hilum while breathing quietly. At

autopsy An autopsy (post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of death or to evaluate any di ...

, splenomegaly can be defined as a spleen weight above the upper limit of the standard reference range of . 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.

Signs and symptoms

Symptoms Signs and symptoms are the observed or detectable signs, and experienced symptoms of an disease, illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormali ...

may include

abdominal pain Abdominal pain, also known as a stomach ache, is a symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than ...

, chest pain, chest pain similar to pleuritic pain when stomach, bladder or bowels are full, back pain, early satiety due to splenic encroachment, or the symptoms of

anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, th ...

due to accompanying

cytopenia Cytopenia is a reduction in the number of mature blood cells. It is common in cancer patients being treated with radiation and/or chemotherapy. Types Anemia – a reduction of the red blood cells in the body. Leukopenia – a deficiency of whit ...

Sign A sign is an object, quality, event, or entity whose presence or occurrence indicates the probable presence or occurrence of something else. A natural sign bears a causal relation to its object—for instance, thunder is a sign of storm, or me ...

s of splenomegaly may include a palpable left upper quadrant abdominal mass or splenic rub. It can be detected on

physical examination In a physical examination, medical examination, or clinical examination, a medical practitioner examines a patient for any possible medical signs or symptoms of a medical condition. It generally consists of a series of questions about the patien ...

by using

Castell's sign Castell's sign is a medical sign assessed to evaluate splenomegaly and typically part of an abdominal examination. It is an alternative physical examination maneuver to percussion over Traube's space. Splenomegaly, although associated with num ...

Traube's space Traube's (semilunar) space is an anatomic space of some clinical importance. It is a crescent-shaped space, encompassed by the lower edge of the left lung, the anterior border of the spleen, the left costal margin and the inferior margin of the lef ...

percussion or

Nixon's sign In medical diagnosis Nixon's sign is an alternative to Castell's sign, useful in identifying splenomegaly Splenomegaly is an enlargement of the spleen. The spleen usually lies in the left upper quadrant (LUQ) of the human abdomen. Splenomegaly is ...

, but an

ultrasound Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...

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.Ovid full text
/ref> 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., which cites * * 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.

Causes

The most common causes of splenomegaly in developed countries are infectious mononucleosis, splenic infiltration with

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

cells from a hematological malignancy and

(most commonly secondary to liver disease, and sarcoidosis). Splenomegaly may also come from bacterial infections, such as

syphilis Syphilis () is a sexually transmitted infection caused by the bacterium ''Treponema pallidum'' subspecies ''pallidum''. The signs and symptoms of syphilis vary depending in which of the four stages it presents (primary, secondary, latent, an ...

or an infection of the heart's inner lining (

endocarditis Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or the ...

). Splenomegaly also occurs in mammals parasitized by ''

Cuterebra fontinella ''Cuterebra fontinella'', the mouse bot fly, is a species of New World skin bot fly in the family Oestridae. ''C. fontinella'' is typically around in length with a black and yellow color pattern. ''C. fontinella'' develops by parasitizing nutrien ...

''. The possible causes of moderate splenomegaly (spleen <1000 g) are many, and include: The causes of massive splenomegaly (spleen >1000 g) are *

chronic myelogenous leukemia Chronic myelogenous leukemia (CML), also known as chronic myeloid leukemia, is a cancer of the white blood cells. It is a form of leukemia characterized by the increased and unregulated growth of myeloid cells in the bone marrow and the accumulat ...

* myelofibrosis *

malaria Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...

splenic marginal zone lymphoma Splenic marginal zone lymphoma (SMZL) is a type of cancer (specifically a lymphoma) made up of B-cells that replace the normal architecture of the white pulp of the spleen. The neoplastic cells are both small lymphocytes and larger, transformed l ...

Pathophysiology

Splenomegaly can be classified based on its pathophysiologic mechanism: * Congestive, by pooled blood (e.g.,

) * Infiltrative, by invasion by cells foreign to the splenic environment (e.g.,

metastases Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...

, myeloid neoplasms, lipid storage diseases) *

Immune In biology, immunity is the capability of multicellular organisms to resist harmful microorganisms. Immunity involves both specific and nonspecific components. The nonspecific components act as barriers or eliminators of a wide range of pathogens ...

, by an increase in immunologic activity and subsequent

hyperplasia Hyperplasia (from ancient Greek ὑπέρ ''huper'' 'over' + πλάσις ''plasis'' 'formation'), or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of organic tissue that results from cell proliferati ...

(e.g.,

sarcoidosis Sarcoidosis (also known as ''Besnier-Boeck-Schaumann disease'') is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph nodes. Less commonly af ...

rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involv ...

) * Neoplastic, when resident immune cells originate a

neoplasm A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

(e.g.,

lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlar ...

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 vaccinated against ''

Haemophilus influenzae ''Haemophilus influenzae'' (formerly called Pfeiffer's bacillus or ''Bacillus influenzae'') is a Gram-negative, non-motile, coccobacillary, facultatively anaerobic, capnophilic pathogenic bacterium of the family Pasteurellaceae. The bacteria ...

'', '' Streptococcus pneumoniae'', and '' Meningococcus''. They should also receive annual influenza vaccinations. Long-term prophylactic

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...

s 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.

References

External links

Splenomegaly and hypersplenism
at patient.info {{Digestive system and abdomen symptoms and signs Diseases of spleen Symptoms and signs: Digestive system and abdomen