SPLENOMEGALY
Spleen is normally palpable in ~15% babies during first 3 months of life. Otherwise, the spleen must enlarge to at least 2-3 times of its size before being palpable clinically. Sub-clinical splenomegaly may be identified by USG, CT scan or 99mTc sulfur colloid scan, last one is also useful to assess splenic function.
Clinically palpable spleen should be differentiated from other common left hypochondriac mass, i.e. kidneys on the basis of—(a) direction of enlargement towards right iliac fossa, (b) movement with respiration,
(c) presence of splenic notch, (d) inability to insinuate fingers below the rib-cage, and (e) absence of colonic band of resonance.
Palpable spleen may be graded according to its size either in terms of actual measurements or as per Hackett's classification (Fig. 19.13). The size of spleen does not indicate its functional status and splenomegaly may be associated with hypersplenism, normal splenic functions or hyposplenism.
Etiology: Splenomegaly may be infective, congestive, hemolytic and infiltrative in origin (Table 19.32). While mild splenomegaly is common in many systemic infections or diseases, chronic malaria, hemolytic anemias and portal hypertension are three leading causes of moderate/severe splenomegaly in Indian children.
Etiological differentiation between these cases depend on the age of presentation, epidemiological prevalence of common causes, size of splenomegaly and coexisting features, e.g. anemia, jaundice, hepatomegaly fever, portal hypertension, etc (Table 19.33). Important diagnostic features of some common disorders with splenomegaly are as follows:
• Infective splenomegaly is the leading cause of splenomegaly, usually associated with history of fever. Malaria is the commonest cause of moderate/severe splenomegaly in Indian children, though kala-azar is common in certain Indian states, e.g.
Bihar and eastern Uttar Pradesh. Mild transient splenomegaly is common in many bacterial and viral infections, including enteric fever and septicemia. Possibility of infective endocarditis should be considered in a child with co-existing heart disease.• Congestive splenomegaly (Banti syndrome) is seen in portal hypertension and spleno-portal venous malformations. These cases usually present with gross splenomegaly and other signs of portal hypertension or hepatic disease, though hepatomegaly
Fig. 19.13: Hackett's classification (numbers indicate severity grading of splenomegaly).
TABLE 19.32: Causes of splenomegaly
• Infections
- Parasitic: Malaria, kala-azar
- Bacterial: Typhoid, septicemia, Inf. endocarditis
- Tubercular: Diss.TB
- Viral: Inf. mononucleosis, CMV
- Spirochetal: Leptospirosis
- Intrauterine: CMV, toxoplasmosis, rubella
• Hemolytic: Hemolytic anemia, iron deficiency
• Congestive: Portal hypertesion, CCF
• Neoplastic (Infiltrative)
- Malignant: Leukemia, lymphoma, secondaries
- Benign: Hemangioma/hamartoma
- Histiocytosis
• Metabolic storage:
- Lipid storage disorders, e.g. Gaucher disease
- Mucopolysaccharidosis
- Glycogen storage disorders
• Others: Cysts, collagen disorders, e.g. SLE, JRA
TABLE 19.33: D/D of common causes of gross splenomegaly
LN: Lymphadenopathy, MR: Develop/mental retardation, FTT: Failure to thrive, PS: Peripheral smear examination
is uncommon. History of perinatal infection and umbilical catheterization should always be asked in these cases. Splenectomy or portocaval anastamosis along with treatment of primary cause may be necessary in these cases.
• Hemolytic splenomegaly is characterized by coexisting hepatomegaly, anemia and often, mild icterus.
Hereditary spherocytosis and thalassemia are two most important hemolytic anemias in children with gross splenomegaly. Unlike thalassemia, severe anemia requiring blood transfusions is uncommon in hereditary spherocytosis. In another common hemolytic anemia, i.e. sickle cell anemia, spleen is enlarged in earlier years but usually regresses by late childhood due to autosplenectomy.• Infiltrative splenomegaly in neoplastic disorders, e.g. leukemia and lymphoma, is frequently associated with hepatomegaly, anemia and lymphadenopathy, along with other signs of malignancy, e.g. bone pains and weight loss. Rare causes of infiltrative splenomegaly include storage disorders, e.g. Gaucher's disease.
Some important clinical problems related to enlarged or hyper-functioning spleen are as follows:
Tropical splenomegaly is a unique problem in children and adolescents of developing countries, characterized by “persistent moderate to severe splenomegaly of unknown etiology, with anemia and malnutrition”. Occasionally, evidences of hypersplenism may also be present.
Etiologically, it is usually considered as an abnormal immune response to chronic infections, e.g. malaria, due to following reasons—(a) high incidence in malaria endemic regions, (b) frequent elevation of anti-malarial IgG titers, (c) regression in splenic size after anti-malaria therapy in some cases, and (d) declining incidence after relative control of malaria. However, a direct evidence, e.g. parasite in splenic puncture, is often absent. Recent evidences have shown non-cirrhotic portal fibrosis with portal hypertension in some cases.
Management is non-specific, though a trial of prolonged anti-malarial therapy (PO chloroquine 5 mg/ kg/week for 6-8 weeks) is often effective in reducing the splenic size in endemic area. Very large splenomegaly or presence of portal hypertension may need splenectomy or portocaval shunt surgery.
Hypersplenism is a clinical complex, characterized by:
• Gross splenomegaly, due to any cause,
• Pancytopenia or bicytopenia, due to excessive cellular destruction in spleen,
• Correction of hematological abnormalities after splenectomy.
Hypersplenism, though nearly always secondary, may or may not respond to treatment of primary cause and splenectomy is necessary in non-responders.
Splenic injuries in children are uncommon unless it is markedly enlarged, and usually caused by blunt abdominal trauma.
Clinically, depending on the size of capsular tear, these cases present with—(a) left hypochondriac or shoulder pain (referred due to peritoneal irritation), (b) hypovolemia, and (c) shock due to massive internal hemorrhage. Cullen sign, i.e. peri-umbilical hyperpigmentation due to hemoperitoneum, is uncommon in children.
Diagnosis may be confirmed by USG/CT scan and 99mTc sulfur colloid scan.
Treatment depends on severity of intra-abdominal bleeding and circulatory status. Close hemodynamic monitoring, serial Hb estimations and blood transfusions as necessary, is all that is required in most cases, which heal spontaneously in 10-14 days. Emergency partial/ total splenectomy is needed in severe cases.
19.16.2