Splenomegaly Flashcards
(16 cards)
Function of spleen
Normal size of spleen
Function of spleen
1. Blood filtration - removes old RBCs, platelets, WBCs, cellular inclusions and debris
2. Immune function - antigen presentation and activation of lymphocytes, antibody production
3. Reservoir - large platelet storage, monocyte, small RBC storage
4. Haematopoiesis in fetus, pathological activation in bone marrows stress/failure
Normal size of spleen: <12cm
Pathophysiology and its causes of splenomegaly
A. Increased function (work hypertrophy)
1. Removal of defective RBCs
- Haemolytic anaemias - hereditary spherocytosis, thalassaemia
- Early stage of sickle cells (late stage shrink)
2. Immune hyperplasia to infection/inflammation
- Proliferation of lymphocytes and macrophages in immune response - infection, inflammatory/autoimmune
3. Removal of abnormal cells/immune complex - AIHA, ITP, SLE
B. Splenic vein and sinusoidal congestion
1. Portal hypertension
- Liver cirrhosis
- Splenic vein thrombosis
- Schistosomiasis
2. Systemic venous congestion
- Right heart failure
- Constrictive pericarditis
C. Splenic infiltration
1. Malignancy - leukaemias, lymphomas myeloproliferative diseases (ET, PRV), mets
2. Metabolic or protein deposition: Gaucher’s, Niemann-Pick, amyloidosis, sarcoidosis, PTB
D. Extramedullary haematopoiesis
- Insufficient production (myelofibrosis)
- Increased demand (chronic haemolytic anaemias - thalassaemia)
E. Primary splenic carcinoma or cysts
- Haemangiomas, lymphangiomas, fibromas, primary splenic lymphoma, parasitic cysts, post-traumatic cysts
What are the causes of splenomegaly?
Commonly encountered in exam: 1. Haematological malignancy 2. Portal hypertension 3. Haemolytic anaemic 4. Felty's syndrome 5. Thalassaemia
Additional on list:
6. Infection (HIV, endocarditis, EBV)
7. Primary splenic disease (splenic vein thrombosis)
8. Haemolysis
9. Glycogen storage disorders
History taking in a patient with splenomegaly
- Constitutional symptoms - fever, night sweats, malaise, weight loss
- Risk factors for HIV
- Risk factors for lymphoma - family history, radiation therapy, immunosuppressive, organ transplant
- Bone and joint pain - secondary hyperuricaemia, myeloproliferative disease
- Pancytopenia - bruising, fatigue, recurrent infection
- Travel history, malaria risk, prophylaxis
- Autoimmune disease
- Liver disease
What are the significance of B-symptoms on Hodgkin’s lymphoma?
Presence of any these alters the patient’s clinical staging:
1. Fever > 38 degree
2. Weight loss >10% body weight in 6 months
3. Drenching night sweats
What are the cytogenetics of chronic myeloid leukaemia?
Philadelphia chromosome present in 90-95% of patients with CML
Chromosomal translocation - fusion of c-abl oncogene of chromosome 9 with bcr on chromosome 22.
–> Increased oncogene activity through tyrosine kinase signalling
Detection of bcr-abl gene for diagnosis and tyrosine kinase monoclonal antibodies for treatment
What are the causes of hyposplenism?
- Splenic infarction (sickle cell, vasculitis)
- Splenic artery thrombosis
- Infiltrative conditions (amyloidosis, sarcoidosis)
- Coeliac disease
- Autoimmune disease
What advice should patients with hyposplenism/post-splenectomy be given?
- Vaccinations (pneumococcal, haemophillus influzena B and meningococcal group C), repeat every 5-10 years
- Prophylactic antibiotics - penicillin or erythromycin for 2 years +/- lifelong
- Malaria prophylaxis and travel advice
- Red flag symptoms for hospitalisation
- Medical alert card or bracelet
What is Felty’s syndrome?
Triad of seropositive arthritis, neutropaenia and splenomegaly
What are the indications for splenectomy?
Rupture
Haematological (ITP, hereditary spherocytosis)
What are the causes of massive splenomegaly?
(Defined as crossing midline, > 8cm from left costal margin)
(M: CML-AMK)
- CML
- Myelofibrosis
- Lymphoma
- AIDS with mycobacterium avium complex
- Malaria
- Kala-azar
What are the causes of moderate splenomegaly?
(size 4-8cm from left costal margin)
(M: A-GPT)
- All causes of massive splenomegaly
- Glycogen and lipid storage disease (Gaucher’s disease)
- Portal hypertension
- Thalassaemia
What are the causes of mild splenomegaly?
(size: <4cm from left costal margin)
- Other myelo/lymphoproliferative disorders - PRV
- Haemolytic anaemia (hereditary spherocytosis, elliptocytosis, ovalocytosis)
- Infection (EBV, infective endocarditis, infective hepatitis)
- Autoimmune disease (RA, SLE)
- Infiltrative disease (amyloidosis, sarcoidosis)
- Acromegaly
- Thyrotoxicosis
What are the characteristics of spleen on palpation?
- Enlarges towards right iliac fossa
- Has a medial notch
- Dull to percussion
(Kidneys are resonant - retroperitoneal due to overlying colon) - Cannot palpate above the spleen
- Not ballotable
Investigations for splenomegaly
- Blood: FBC, PBF, LFT, LDH, autoimmune screen, B2M
- CXR
- HIV testing
- Imaging
- Ultrasound HBS and spleen
- CT TAP: for disseminated malignancy, lymph node
- PET - Bone marrow and lymph node biopsy
Approach to Splenomegaly
- Size of splenomegaly
- Typical spleen: 12cm length, only palpable once >15cm
- Subtle changes - dull percussion over Traube space (usually resonant from stomach)
- Size determines possible etiologies
- Differentiating signs from polycystic kidney - Pancytopenia
- Anaemia: conjunctival pallor
- Thrombocytopenia: easy bruising
- Lymphopenia: infection related signs - Hyperbilirubinaemia +/- pruritus
- Without hepatomegaly -> haemolytic anaemia (AIHA, CLL)
- With hepatomegaly -> thalassaemia, chronic liver disease, malignancy - Stigmata of chronic liver disease
- Positive -> possible portal hypertension as cause of splenomegaly
- Venous hum over epigastrium - Lymphadenopathy
- Positive -> lymphoproliferative disorder or Felty’s syndrome
- Negative -> myeloproliferative disorder but ask for imaging to evaluate
