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ukmla 2026

Splenomegaly

Enlargement of the spleen — a clinical sign with a broad differential including haematological malignancy, portal hypertension, infection, and autoimmune disease

Review date
reviewed 2026-04-05
Reading time
5 min read
Author
Dr Kola Tytler MBBS CertHE MBA MSt MRCGP
Haematology & Oncologyless-commonchronic
On this page
Condition details
Haematology & Oncology
less-common
5 min read
reviewed 2026-04-05
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About This Page

This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.

Key points

  • Splenomegaly is a SIGN, not a diagnosis — always investigate the underlying cause
  • Most common causes in UK: portal hypertension (liver disease), haematological malignancy (CML, lymphoma, CLL, myelofibrosis), infection (EBV, malaria)
  • MASSIVE splenomegaly (crossing midline/into pelvis): CML, myelofibrosis, visceral leishmaniasis, malaria, Gaucher disease
  • Hypersplenism: enlarged spleen sequesters and destroys blood cells → pancytopenia
  • Post-splenectomy/asplenic patients: lifelong risk of overwhelming post-splenectomy infection (OPSI) from encapsulated organisms — vaccination and penicillin prophylaxis essential

Overview

The spleen performs immune surveillance, filters old/abnormal red blood cells, and acts as a reservoir for platelets and red cells. Splenomegaly occurs when the spleen enlarges due to increased workload (haemolysis, infection), infiltration (malignancy, storage diseases), congestion (portal hypertension), or immune stimulation (autoimmune disease). A normal spleen is not palpable — when the spleen becomes palpable on clinical examination, it is already approximately 2-3 times its normal size. Splenomegaly may be an incidental finding or present with left upper quadrant discomfort, early satiety, or cytopenias from hypersplenism.

Epidemiology

The prevalence of splenomegaly depends on the underlying cause and population studied. In the UK, portal hypertension from chronic liver disease and haematological malignancies are the most common causes. In tropical regions, malaria and visceral leishmaniasis are major causes. Infectious mononucleosis (EBV) is a common cause of transient splenomegaly in young adults.

Clinical Features

Symptoms
Left upper quadrant discomfort or fullness
Early satiety (enlarged spleen compresses stomach)
Left shoulder tip pain (diaphragmatic irritation or splenic infarction)
Symptoms of underlying cause: fatigue, weight loss, night sweats (malignancy); fever (infection); jaundice (liver disease)
Signs
Palpable spleen — examined from the right iliac fossa, moves with respiration, cannot get above it (below left costal margin)
Splenic notch palpable on medial border — distinguishes spleen from left kidney
Hepatomegaly (portal hypertension, haematological malignancy)
Lymphadenopathy (lymphoma, CLL, infection)
Stigmata of chronic liver disease (portal hypertension)
Pallor, jaundice (haemolysis, liver disease)

Investigations

First-line
FBC and blood filmCytopenias from hypersplenism (pancytopenia). Film: abnormal cells (blasts → leukaemia; atypical lymphocytes → EBV; target cells → haemoglobinopathy; tear-drop cells → myelofibrosis)
LFTsDeranged in liver disease/portal hypertension
LDH, bilirubin, reticulocytes, haptoglobinHaemolysis screen — if haemolytic cause suspected
Second-line
Abdominal ultrasoundConfirms splenomegaly (normal spleen <12 cm), assesses liver architecture, portal vein diameter, ascites
Monospot / EBV serologyIf young patient with acute splenomegaly + sore throat + atypical lymphocytes → infectious mononucleosis
Thick and thin blood filmsIf recent travel to endemic area — exclude malaria
Autoimmune screenANA, dsDNA, complement (SLE), DAT (autoimmune haemolysis), rheumatoid factor (Felty syndrome: RA + splenomegaly + neutropenia)
Specialist
CT chest/abdomen/pelvisIf malignancy suspected — staging lymphoma, identifying other sites of disease
Bone marrow biopsyIf haematological malignancy suspected — CML, myelofibrosis, lymphoma with marrow involvement
JAK2 mutation / BCR-ABL1If myeloproliferative neoplasm suspected (PV, myelofibrosis, CML)
Haemoglobin electrophoresisIf haemoglobinopathy suspected (thalassaemia, sickle cell)

Management

BSH Guidelines + clinical practice
1
Treat the underlying cause
  • This is always the primary approach — splenomegaly is a sign, not a primary diagnosis
  • Haematological malignancy: appropriate chemotherapy/targeted therapy
  • Portal hypertension: manage liver disease, consider TIPS
  • Infection: antimicrobials as appropriate
  • Autoimmune: immunosuppression
2
Splenectomy
  • Indications: symptomatic massive splenomegaly, refractory cytopenias from hypersplenism, staging/diagnosis, haemolytic conditions (hereditary spherocytosis), traumatic splenic rupture
  • Pre-splenectomy: vaccinations AT LEAST 2 weeks before (pneumococcal, Hib, meningococcal ACWY and B)
  • Post-splenectomy: lifelong penicillin V prophylaxis (250 mg BD), annual influenza vaccination, medic alert bracelet
3
Asplenic/hyposplenic patient care
  • Overwhelming post-splenectomy infection (OPSI): encapsulated organisms (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis) — can be rapidly fatal
  • Lifelong penicillin V prophylaxis (or erythromycin if penicillin-allergic)
  • Vaccinations: pneumococcal (PCV13 then PPV23), Hib, MenACWY, MenB, annual influenza
  • Patient education: seek IMMEDIATE medical attention for ANY fever or rigours — treat empirically with broad-spectrum antibiotics without waiting for culture results
  • Medic alert bracelet/card
  • Malaria prophylaxis and tick bite prevention — asplenic patients at increased risk of severe Babesia and malaria

Complications

  • Hypersplenism: Cytopenias from excessive splenic sequestration and destruction of blood cells
  • Splenic rupture: Risk in EBV mononucleosis (avoid contact sports for 6-8 weeks), trauma. Presents with acute abdomen and haemodynamic instability — surgical emergency
  • Splenic infarction: Severe pain, fever — seen in sickle cell, myeloproliferative neoplasms, infective endocarditis (septic emboli)
  • OPSI (post-splenectomy): Fulminant sepsis from encapsulated organisms — 1-5% lifetime risk, mortality 40-50% if untreated
UKMLA Exam Tips
  • 1MASSIVE splenomegaly (crossing midline) differential: CML, myelofibrosis, visceral leishmaniasis (kala-azar), malaria, Gaucher disease — learn this short list
  • 2Spleen moves with respiration, has a notch, cannot get above it, is dull to percussion — the classic clinical examination teaching points
  • 3EBV splenomegaly: advise AVOIDING contact sports for 6-8 weeks due to risk of splenic rupture
  • 4Post-splenectomy: Howell-Jolly bodies on blood film (nuclear remnants not removed by absent spleen) — classic finding
  • 5Post-splenectomy vaccination: pneumococcal + Hib + MenACWY + MenB — given ≥2 weeks BEFORE elective splenectomy
  • 6Felty syndrome: rheumatoid arthritis + splenomegaly + neutropenia — classic clinical triad
  • 7Any asplenic patient with fever must be treated as a medical emergency — IV antibiotics immediately

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Verified Sources & References

BSH Guidelines — Prevention of Infection in Patients with Absent or Dysfunctional Spleen
NICE CKS — Splenomegaly
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