• Skin-directed therapy in mycosis fungoides: creams, light and small radiotherapy fields: Early mycosis fungoides is treated on the skin, not through the bloodstream.
• Watch and wait in lymphoma: when the right treatment is none yet: For slow-growing lymphomas that are not causing symptoms, treating straight away does not help people live longer.
• Indolent and aggressive lymphoma: Lymphomas are split by how fast they grow, and the split decides what happens next.
• Nodal and extranodal lymphoma: A lymphoma that starts in a lymph node is called nodal; one that starts in an organ is called extranodal.
• 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.

Making the diagnosis, which needs the history as much as the biopsy: The biopsy shows large atypical CD30-positive cells that on their own would suggest an aggressive lymphoma. What makes the diagnosis is the course: crops of papules that ulcerate, crust and heal on their own over three to twelve weeks, often leaving small scars, recurring over years. Photographs and a dated history are part of the diagnostic record, not an extra. Staging confirms there is no disease outside the skin.

Biomarker results to ask for: CD30-positive large atypical cells on the biopsy, which on their own would suggest an aggressive lymphoma, The clinical course, which is the diagnosis: crops of lesions that ulcerate and heal on their own over weeks, A clonal T-cell receptor rearrangement in many cases, which does not make it a cancer in the way it would elsewhere, Absence of ALK, Continuing surveillance for a second lymphoma, most often mycosis fungoides, primary cutaneous anaplastic large cell lymphoma or Hodgkin 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.

• Treatment, which is often none: No treatment has been shown to change the course or to reduce the risk of a second lymphoma, so treatment is for the lesions that bother the person. Observation with emollients and an explanation is a legitimate plan for somebody with a few lesions, and in the published series nobody has died of this condition. Where crops are frequent, numerous or scarring, low-dose weekly methotrexate, phototherapy or potent topical steroids suppress them, and the lesions return when treatment stops. Combination chemotherapy has no place. (Methotrexate, Skin-directed therapy in mycosis fungoides: creams, light and small radiotherapy fields, Watch and wait in lymphoma: when the right treatment is none yet)
• Why follow-up continues in a condition that does not shorten life: People with lymphomatoid papulosis have a raised risk of a second lymphoma, most often mycosis fungoides, primary cutaneous anaplastic large cell lymphoma or Hodgkin lymphoma, which may come before, alongside or after the skin lesions. Continuing dermatological review, and biopsy of any lump that behaves differently from the usual crops, is the reason for follow-up. Nothing prevents the second lymphoma, so the aim is to find it early. (Mycosis fungoides, Primary cutaneous anaplastic large cell lymphoma, Hodgkin lymphoma, Histopathology & immunohistochemistry)

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