Mature -T- Cell Neoplasms

Description: 
TESTS AVAILABLE: Karyotyping and FISH.
FISH:
Anaplastic large cell lymphoma: t(2;5)(p23;q35) and variants, ALK Dual Colour, Break Apart Rearrangement Probe,
T-Cell Prolymphocytic leukaemia (T-PLL): Inv(14)(q11q32) Trisomy for chromosome 8, TCR alpha/delta Dual Colour Break apart Rearrangement Probe, CEP 8 Spectrum Orange/Aqua.

Clinical details: 
The WHO classification takes account of 18 mature T-cell neoplasms of which only the most relevant will be dealt with here. It would be advisable to consult the latest WHO Classification of tumours of Haematopoietic and Lymphoid tissues when and where necessary.
1. T-cell PLL. This is an aggressive T-cell leukaemia. The most frequent chromosome abnormalities in T-PLL involve inversion of chromosome 14, at breakpoints q11 and q32 seen in about 80% of patients. A variant of this, the t(14;14)(q11;q32) also exists. Both of these juxtapose the TCRA locus with the oncogenes TCL1A and TCL1B at 14q32. Abnormalities of chromosome 8 are also seen in addition to ETV6 AND TP53 deletion. The course of this case is aggressive with a median survival of less than one year.
2. Natural NK-cell leukaemia. A systemic neoplastic proliferation of natural killer cells associated with Epstein Barr Virus (EPV). A variety of clonal cytogenetic abnormalities have been reported such as deletions of the long arms of 6 and 11. An iso 7q and trisomy 8 have also been reported.
3. Adult T-cell leukaemia/lymphoma (ATLL). This is associated with the human retrovirus (HTLV-1) and involves rearrangement of t-cell receptor genes. Prognosis is poor.
4. Hepatosplenic T-cell Lymphoma (HSTL). This is a systemic lymphoid neoplasm and the clinical course is aggressive with a median survival of less than two years. TCR genes are rearranged and iso7q is present cytogenetically in most cases as well as other abnormalities of 7q. Trisomy 8 or loss of a sex chromosome can also be seen.
5. Mycosis Fungoides. This is an epidermotrophic T-cell lymphoma. Complex karyotypes are present in many patients in particular in the advanced stages. T-cell receptor genes are rearranged.
6. Anaplastic large cell lymphoma (ALCL),ALK-positive. This is a T-cell lymphoma where in approximately 90% of cases show a rearrangement of the ALK gene at 2p23. This rearrangement can take the form of a translocation or inversion. The most common translocation is the t(2;5)(p23;q35) (ALK/NPM1) and can readily be detected with FISH probes. The prognosis is favourable compared to ALK negative cases.

Synonyms or keywords: 
T-Cell leukaemia, TCR
Sample type and Volume required: 
Bone Marrow Aspirate -first draw or Blood in Lithium Heparin if FISH only studies required.
Turnaround time: 
Please refer to Cytogenetics User Guide
Special sample instructions: 

All samples must be delivered to the laboratory within 24 hours of collection.

Contacts:
HMDC Department at King's College Hospital
020 3299 9000 ext 32414
c/o Central Specimen Reception
Blood Sciences Laboratory
Ground Floor Bessemer Wing
King’s College Hospital
Denmark Hill
London SE5 9RS
Mon-Fri, 9.00am-5.30pm
For clinical advice or interpretation of results, please contact the laboratory in the first instance.

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Last updated: 03/07/2017