Paediatric Lymphoma Flashcards
What is lymphoma?
A group of malignancies which arise within the lymphatic system, which includes lymph nodes, the spleen, the thymus and the bone marrow.
What distinguishes lymphomas form leukaemia?
One of the key features which distinguish most lymphomas from leukaemia is that the malignant cells are mature lymphocytes, and they arise within sites outside of the bone marrow (e.g. lymph nodes). In contrast, leukaemia develops from immature blasts and arises within the bone marrow.
What distinguishes lymphoblastic lymphomas from leukaemia?
The way in which lymphoblastic lymphomas are distinguished from lymphoblastic leukaemia is the degree of bone marrow infiltration by blasts; <25% bone marrow involvement is lymphoma, while >25% is leukaemia. However, these are treated the same as acute lymphoblastic leukaemia (ALL).
How is Hodgkin’s lymphoma histologically characterised?
Hodgkin’s lymphoma is characterised histologically by the presence of Reed-Sternberg cells (giant multinucleated cells), with associated smaller mononuclear cells, which arise from B lymphocytes.
Name 2 risk factors associated with developing a lymphoma.
Immunodeficiency: post-solid organ transplant (post-transplant lymphoproliferative disorders), ataxia telangiectasia, Nijmegan-Breakage syndrome, HIV, and immunosuppressant drugs.
Epstein-Barr virus infection
Describe how a child with lymphoma would present.
Patients commonly present with painless, progressive lymphadenopathy (develops over weeks-months).
Other symptoms of lymphoma include:
B symptoms: fatigue, drenching night sweats, fever >38oC, weight loss (>10% in 6 months).
Pruritus
Mediastinal involvement (thymus or mediastinal lymph nodes): dyspnoea, cough, chest pain.
Describe some symptoms of childhood lymphoma which indicated extra nodal involvement.
Bone marrow: symptoms of anaemia, infections, easy bruising/bleeding.
Abdomen: bloating, early satiety, pain, unable to pass stools and vomiting if obstructed.
Retroperitoneal lymphadenopathy: urinary retention.
Skin: new skin lesions (such as mycosis fungoides), or jaundice.
Testicular swelling
Central nervous system: behavioural change, headache, confusion, nausea and vomiting, seizures, weakness, sensory changes.
Describe some typical clinical findings of lymphoma.
Non-tender, firm, matted lymph nodes (more likely to be malignant)
Hodgkin’s: often cervical, supraclavicular, axillary
Non-Hodgkin’s: more rapidly growing bulky lymphadenopathy
Mediastinal mass: may cause severe effects such as SVC obstruction, effusions, or airway obstruction
Abdomen: splenomegaly, hepatomegaly, abdominal mass
Skin: T cell lymphomas including mycosis fungoides, jaundice
Testicular mass
Neurological: weakness, sensory abnormalities, features of raised intracranial pressure
Describe the relevant imaging investigations relevant to bone tumours.
Chest X-ray: can show a mediastinal mass arising from the lymph nodes or thymus, intrathoracic lymph nodes, or effusions.
CT/MRI/PET scans: for staging purposes
Ultrasound of the liver and spleen
Name the classification used in Hodgkin’s lymphoma.
Ann Arbor
Name the classification used in Non-Hodgkin’s lymphoma.
St Jude classification
Name the electrolyte imbalances in tumour lysis syndrome.
hyperphosphataemia, hyperkalaemia, hypocalcaemia, hyperuricaemia
Name some clinical manifestations of tumour lysis syndrome.
Acute kidney injury
Cardiac arrhythmias
Nausea and vomiting
Seizures.
Name 3 important prophylactic medical measures that should be prescribed before chemotherapy and why.
Prophylactic hydration and allopurinol are important prior to chemotherapy. Rasburicase may be used if white cell count is >50, as this will actively break down the uric acid, while allopurinol prevents uric acid production.
What should be excluded before prescribing rasburicase and why?
G6PD deficiency should be excluded before giving rasburicase as it increases the risk of haemolytic crisis.
