• International Prognostic Index (IPI): A five-point score (age, stage, performance status, LDH, extranodal sites) that predicts how risky a lymphoma is before treatment.
• Prognostic Index for T-cell lymphoma (PIT): A four-item score that estimates the outlook in nodal T-cell lymphoma, built because the index used for B-cell lymphoma separated these patients poorly.
• B-cell, T-cell and NK-cell lymphoma: The first thing a lymphoma report says is which kind of lymphocyte the cancer came from.
• Stem cell transplant in lymphoma: what it is still for: An autologous transplant is very high-dose chemotherapy followed by the patient's own stored stem cells to rescue the bone marrow.
• Lugano classification / Ann Arbor staging: The Lugano classification is the lymphoma staging system: stage I to IV by how many lymph node regions and organs are involved, with PET-based response criteria.
• The two lymphoma classifications of 2022 (WHO-HAEM5 and ICC): Since 2022 there have been two reference classifications of lymphoma rather than one, published within months of each other by overlapping groups of experts.
• The lymphoma regimen alphabet: R-CHOP, pola-R-CHP, DA-EPOCH-R, ABVD, BEACOPP and the rest: Lymphoma treatment is written in acronyms, one letter per drug.

Making the diagnosis, and the mistake to avoid: Immunohistochemistry for CD30 and for ALK protein on the biopsy, with fluorescence in situ hybridisation to confirm the rearrangement where the stain is equivocal. The large pleomorphic cells, the frequent expression of epithelial membrane antigen and the loss of several T-cell markers mean that a tumour stained with a short panel can be reported as a carcinoma or a sarcoma; CD30 and ALK are what prevent that. Staging covers the sites this disease reaches outside the lymph nodes: skin, bone, soft tissue, lung and liver.

Biomarker results to ask for: ALK rearrangement, most often NPM1::ALK from t(2;5)(p23;q35), detected by immunohistochemistry for the ALK protein and confirmed by fluorescence in situ hybridisation, Uniform strong CD30 on every tumour cell, which is what brentuximab vedotin attaches to, Loss of several T-cell markers, which is characteristic and can make the lineage hard to establish, Epithelial membrane antigen, often positive, which contributes to the mistaken diagnosis of carcinoma, The International Prognostic Index, which separates outcomes here as it does in B-cell lymphoma.

Scans and tests linked to this cancer: FDG PET, Histopathology & immunohistochemistry.

Bring copies of scan reports, pathology and blood results, and a list of every medicine and supplement.

• First-line treatment: Brentuximab vedotin with cyclophosphamide, doxorubicin and prednisone, on the strength of ECHELON-2, which randomised 452 people with untreated CD30-positive peripheral T-cell lymphoma, three-quarters of them with systemic anaplastic large cell lymphoma: five-year progression-free survival 51.4 per cent against 43.0 and overall survival 70.1 against 61.0 with chemotherapy alone. Vincristine is left out because brentuximab vedotin is itself a tubulin-directed agent and giving both causes unacceptable nerve damage. Unlike the other nodal T-cell lymphomas, ALK-positive disease does well enough that consolidating a first remission with an autologous transplant is generally not offered. The regimens and the cycle detail are on the peripheral T-cell lymphoma page. (ECHELON-2, Brentuximab vedotin, Cyclophosphamide, Doxorubicin, Prednisone, Peripheral T-cell lymphomas (including cutaneous T-cell lymphoma), The lymphoma regimen alphabet: R-CHOP, pola-R-CHP, DA-EPOCH-R, ABVD, BEACOPP and the rest)
• Relapse: Brentuximab vedotin is highly active in relapsed systemic anaplastic large cell lymphoma, with response rates well above those seen in other peripheral T-cell lymphomas, and it is the usual choice for anyone who has not already had it. ALK inhibitors developed for lung cancer, crizotinib in particular, produce responses here and are used especially in children and young adults. Allogeneic transplant is offered to fit patients who respond. The detail is on the peripheral T-cell lymphoma page. (Brentuximab vedotin, Peripheral T-cell lymphomas (including cutaneous T-cell lymphoma), Allogeneic stem cell transplantation, Stem cell transplant in lymphoma: what it is still for, ALK)

From the standard of care recorded for this cancer; which apply depends on your stage and biomarkers. Ask which the team recommends and why.