Our patient was found to have systemic anaplastic lymphoma kinase (ALK) positive anaplastic large cell lymphoma (ALCL).
ALK-positive ALCL is a rare, mature T-cell non-Hodgkin lymphoma (NHL).
Key learning points:
1. Epidemiology
- 3% of all adult NHL
- 10 – 20% of all childhood NHL
- More common in males 1.5:1 (male:female)
- Commonly occurs before the age of 30
2. Clinical features
- Frequently involves extranodal sites such as skin, soft tissue, liver, lung, bone
- Rarely involves the mediastinum, gut or CNS
- Majority of patients present with advanced disease (stage III/IV) ~70%
- Majority of patients present with B symptoms ~75%
3. Pathology
- Lymphoid cells are usually large with abundant cytoplasms and pleiomorphic ‘horseshoe-shaped’ nuclei, this is known as then ‘common pattern’. Variant histology includes the small cell and lymphohistiocytic patterns.
- Pathological cells contain a chromosomal translocation that involves the ALK gene and express ALK protein and CD30.
4. Prognosis
- Risk stratification should be completed using IPI index
- ALK positivity is an important prognostic marker as 5 year overall survival is greater in patients with ALK+ ALCL (~80%) than in ALK- ALCL (50%), however this may reflect the comparatively younger patient age group, rather than ALK expression
5.Treatment
First line
- CHOP – cyclophosphamide, doxorubicin, vincristine, prednisone
- CHOEP – as above plus etoposide
Consolidation
- Auto-SCT
Second line
- GDP – gemcitabine, dexamethasone, cisplatin
- Brentuximab vedotin (NICE approved in the UK for a minimum of 8 and maximum of 16 cycles)
Consolidation
- Auto/allo
Clinical trials:
- Brentuximab vedotin as 1st line therapy?
References:
WHO classification of Tumours of haematopoietic and lymphoid tissues (2017) Swerdlow et. al.
The biology and management of systemic ALCL, Hapgood et. al. 2015 Jul 2;126(1):17-25. doi: 10.1182/blood-2014-10-567461
