10- Haematology (Lymphadenopathy and the spleen))

Question 1

The lymphatic system background

Answer 1

• Series of vessels and nodes that collect and filter excess tissue fluid (lymph), before returning it to venous circulation

Question 2

Lymph organs

Answer 2

• Spleen
• Thymus- development and maturation of T lymphocytes
• Red bone marrow- maturation of immature lymphocytes

Question 3

Lymph nodes

Answer 3

1) Kidney shaped sturctures
2) Filter particles from the blood
3) Immune function
Each node contains:
- T cells, B cells and other immune cells
- They are exposed to fluid as it passes through the node and commence and immune response if they detect the presence of a pathogen

Question 4

Lymphadenopathy background

Answer 4

• Swelling of lymph nodes
• When nodes accumulate an excessive amount of lymphocytes they can become swollen

Question 5

causes of lymphadenopathy

Answer 5

Infective
Neoplastic
Others

Question 6

infective causes of lyphadenopathy

Answer 6

• Infectious mononucleosis
• HIV, including seroconversion illness
• eczema with secondary infection
• rubella
• toxoplasmosis
• CMV
• tuberculosis
• roseola infantum

Question 7

Neoplastic causes of lymphadenopathy

Answer 7

• Leukaemia
• Lymphoma

Question 8

other causes of lymphadenopathy

Answer 8

Others
- Autoimmune conditions: SLE, rheumatoid arthritis
- Graft versus host disease
- Sarcoidosis
- Drugs: phenytoin and to a lesser extent allopurinol, isoniazid

Question 9

Investigations for lymphadenopathy

Answer 9

• Imaging
  o US
  o CT scan or MRI
• Lymph node biopsy

Question 10

the spleen location

Answer 10

• Upper left abdomen
• Size of clenched fist

Question 11

Function of the spleen

Answer 11

In an adult main function is to filter blood, removing old RBC. Also has a role in cell-mediated and humoral immune responses

• Red pulp
  –> Recycles RBCs and metabolised Hb
• White pulp
  –> Antibody synthesis
  –> Removal of opsonised bacteria/blood cells
• Sequestration and phagocytosis of old/abnormal cells by macrophages
• Blood pooling -> so platelets and RBCs can be rapidly mobilised during bleeding
• Extramedullary haemopoiesis -> during haematological stress or if bone marrow fails e.g. myelofibrosis
• Immunological function
  –> 25% of T cells and 15% of B cells are present in the spleen

Question 12

Vasculature of the spleen

Answer 12

• Most of its arterial supply from the splenic artery, a vessel which arises from the coeliac trunk
• Venous drainage through splenic vein

Question 13

Lymphatics of the spleen

Answer 13

Lymphatic vessels of the spleen follow the splenic vessels and drain into the pancreaticosplenic lymph nodes and then the coeliac nodes

Question 14

Spleen rupture

Answer 14

• Common site of injury
• Splenic rupture occurs when there is a break in its fibroelastic capsule, disrupting underlying parenchyma
• Mode of injury
  o Blunt or penetrating trauma
  o Associated with left rib fracture
• Results in profuse bleeding into the peritoneal cavity because it is highly vascular

Question 15

management of spleen rupture

Answer 15

Splenectomy
- When injury and subsequent haemorrhage are life threatening
- Can be partial or total
- Liver and bone marrow take over some functions of the spleen
- Lifelong antibiotics

Question 16

Complications of spleen rupture and splenectomy

Answer 16

• Higher risk of encapsulated bacterial infections

Question 17

Splenomegaly background

Answer 17

• Abnormally large spleen >12cm
• Usually a result of secondary causes rather than primary disease of the spleen
• Massive splenomegaly - >20cm

Question 18

causes of splenomegaly

Answer 18

1) Blood cancers
- Leukaemia’s
- Lymphomas

2) Infections (due to increased work of spleen)
- Infectious mononucleosis
- Parasitic infections e.g. malaria
- Bacterial endocarditis
- Viral hepatitis

3) Portal hypertension
- Cirrhosis

4) Less common conditions
* Haemolytic anaemics
* Sickle cell
* Thalassaemia
* Autoimmune
* SLE
* RA
* Metabolic
* Gaucher disease

Causes of massive splenomegaly
- Myelofibrosis
- Chronic myelogenous leukaemia
- Malaria

Question 19

Causes of massive splenomegaly

Answer 19

myelofibrosis
CML
malaria
visceral leishmaniasis

Question 20

causes of moderate splenomegaly

Answer 20

lymphoproliferative
portal hypertension
thalassaemia

Question 21

causes of mild splenomegaly

Answer 21

PRV (polycythaemia vera)
Haemoloytis
Infection
Infiltration
Connective tissue disorders

Question 22

Presentation of splenomegaly

Answer 22

• Abdominal pain/ distention
• Constitutional symptoms: night sweats, fever, weight loss, malaise
• Abnormal bruising/bleeding
• Anaemic symptoms
• Decreased appetite (stomach squishes by spleen)

Question 23

splenomegaly investigations

Answer 23

• Bloods: FBC, blood film, LFTs, UEs, autoimmune screen, CRP, LDH
• Imaging
  o US
  o CT
  o MRI (blood flow)

Question 24

management of splenomegaly

Answer 24

treat underlying causes

1) Avoid source of abdominal injury to prveent rupture

2) Splenectomy
- vaccination
- prophylactic antibiotics

Question 25

summary of splenomegaly

Answer 25

Question 26

asplenia

Answer 26

absence of spleen due to congenital anomaly or surgical procedure

Question 27

Hyposplenism

Answer 27

: reduced or absent function of spleen, impairing capacity to prevent bacterial infections

Question 28

causes of hyposplenism

Answer 28

**1) Planned**, where prophylactic measures can be used to prevent later complications. **2) Traumatic**, due to an accident or during surgery. **3) Autosplenectomy**, which refers to the physiological loss of spleen function (hyposplenism) - eg, associated with sickle cell anaemia (chronic damage to the spleen results in atrophy), coeliac disease, dermatitis herpetiformis, essential thrombocythaemia and ulcerative colitis.

Question 29

Indication for splenectomy

Answer 29

- Trauma - Spontaneous rupture e.g. caused by splenomegaly due to infectious mononucleosis - Hypersplenism – immune thrombocytopenia - Neoplasia

Question 30

Complication of splenectomy

Answer 30

- Thrombocytosis - increased risk of VTE, but prophylactic aspirin may be given if very high - Infection by **encapsulated bacteria (NHS)** o Streptococcus pneumonia o Haemophilus influenzae o Neisseria meningitis

Question 31

Investigations for hyposplenism

Answer 31

- Blood film: features of hyposplenism include **Howell-Jolly bodies, Pappenheimer bodies, target cells and irregular contracted red blood cells** - Imaging techniques: ultrasound, CT scanning, and MRI scanning. - Other investigations, which will depend on the clinical context.

Question 32

Complications of hyposplenism

Answer 32

- Increased risk of NHS encapsulated bacterial infections - Increased risk of severe falciparum malaria

Question 33

which immunisations are important for people without a spleen or hyposplenism

Answer 33

* H.influzenae type B * Influenza virus * Pneumococcal * Meningococcal ACWY and B

Question 34

antibiotic prohylaxis in hyposplenism

Answer 34

For those at high risk of pneumococcal infections Types: - Phenoxypenicillin - Macrolides

Question 35

Risk factors for high risk hyposplenism

Answer 35

* Age <16 years or >50 years. * Poor response to pneumococcal vaccination. * Previous invasive pneumococcal illness. * Underlying haematological malignancy resulting in splenectomy (increased risk if immunosuppressed).

Question 36

pancytopenia background

Answer 36

- Low levels of RBC, WBC and platelets o RBC- oxygen delivery o WBC- immune o Platelets- haemostasis - Increases risk of infection and bleedings

Question 37

Causes of pancytopenia

Answer 37

Usually unknown - Cancer e.g. acute leukaemia’s, chemotherapy or radiation - Genetic conditions - Vitamin B12 and folate deficiency - Autoimmune conditions which attack the bone marrow - Some medicines e.g. antiseizure, antibiotics

Question 38

presentation of pancyto penia

Answer 38

- Anaemic symptoms - low WBC symptoms - Thrombocytopenic symptoms

Question 39

Anaemic symptoms

Answer 39

* Weakness * Fatigue * Rapid heart rate * SoB * Pale skin

Question 40

Low WBC symptoms

Answer 40

Frequent infections

Question 41

Thrombocytopenic symptoms

Answer 41

* Petechiae * Bleeding from the gums or nose, blood in faeces or urine, heavy bleeding from cut * Heavy menstruation in female * Easy bleeding

Question 42

Investigation for pancytopenia

Answer 42

- Bloods o Full blood count o Blood culture o Clotting/coagulation studies o Group and cross-match blood o U&Es o CRP - Bone marrow biopsy

Question 43

management of pancytopenia

Answer 43

Management - Treat underlying cause o E.g. drugs which stimulate bone marrow o Drugs which suppress immune system attacking bone marrow - Blood transfusion o May prevent bleeding or organ damage o Does not treat pancytopenia - Stem cell transplant