Immune dysregulation, lymphoproliferation and autoinflammatory disease — OSCE

Station brief (candidate)

• Acknowledge the parents' fear of cancer and validate it as reasonable, given their family history.
• Explain that chronic, painless lymphadenopathy with a big spleen and a falling platelet count, in a child who is otherwise well between episodes, points toward an immune-control disorder called autoimmune lymphoproliferative syndrome (ALPS) — not cancer — while honestly stating that cancer must be actively excluded.
• Outline the work-up that distinguishes the two: a blood film and, if needed, a lymph-node biopsy to exclude lymphoma, alongside an immunophenotype looking for double-negative T cells, and a phenotype-guided gene panel of the Fas pathway.
• Outline the management principle: steroid-sparing sirolimus rather than splenectomy, with clinical immunology referral.
• Agree a clear, specific safety-net for when to return immediately (new fever with bleeding or bruising, progressive gland enlargement, persistent fever, breathlessness). [6] [7]

Role-player notes

You are frightened parents. Your brother died of childhood cancer, and you have been watching your son's glands grow for a year, terrified. You become more anxious if the doctor dismisses your fear, says "it's nothing" before testing, or refuses to discuss cancer. You calm down and engage well when the doctor names the likely condition in plain language, honestly says cancer must be ruled out with specific tests, explains that this disorder is a failure of the immune system's off-switch rather than a tumour, and gives you a clear timeline and a written safety-net. You want to know whether removing the spleen or the glands would fix it. [1]

Expected candidate performance

1. Opening: "I can see how frightening a year of watching your son's glands grow has been, especially after your family's loss. The good news is that the pattern — painless glands and a spleen that have been there a long time, in a child who is otherwise well between times — points us toward a treatable disorder of the immune system's controls rather than a tumour. But I take your fear seriously, and we will actively rule cancer out." [1]
2. Diagnosis explained simply: ALPS is a condition in which the immune system's off-switch — the signal that tells activated defence cells to die once their job is done — does not work, so the cells accumulate as enlarged glands and spleen and can attack blood cells such as platelets. It runs in families and is not cancer. [6]
3. The work-up: A blood film to look for any abnormal cells, and a lymph-node biopsy if there is any doubt, to exclude lymphoma. Then a special blood test — an immunophenotype — to look for a particular population of cells called double-negative T cells that characterise ALPS, and a genetic test of the Fas pathway to confirm. [6]
4. The management: The preferred treatment is a tablet called sirolimus that calms the overactive cells and protects the platelets, supervised by a clinical immunologist. I would avoid removing the spleen, because it does not cure the condition and raises the risk of serious infection. [7]
5. Safety-net: Return immediately if your son develops a new fever with unusual bruising or bleeding, progressively enlarging glands, a gland that becomes hard or fixed, persistent fever, or breathlessness. Otherwise we review with the test results at the agreed time. [8]
6. Communication: Use teach-back to confirm the parents can repeat the plan and the safety-net; offer written information and a contact for the immunology team; arrange interpreter or culturally appropriate support if needed. [1]

Marking domains

• Validates the parents' fear of cancer without dismissing it, and sets up an honest plan to exclude it.
• Names ALPS and explains the failed off-switch in plain language.
• Outlines the correct distinguishing work-up: film and biopsy to exclude lymphoma, immunophenotype for double-negative T cells, Fas-pathway gene panel.
• States the steroid-sparing sirolimus-first principle and the avoidance of splenectomy.
• Gives a specific, written safety-net and confirms understanding with teach-back. [6] [7]

Common fails

• Reassuring that "it is not cancer" before any testing has excluded lymphoma.
• Failing to order a blood film or node biopsy to exclude malignancy in chronic lymphadenopathy with cytopenia.
• Reaching for splenectomy as a surgical fix, ignoring its sepsis risk and lack of durable cure in ALPS.
• Ordering a non-specific autoantibody or allergy panel instead of a phenotype-guided immunophenotype and gene panel.
• Sending the family home without a specific safety-net for the cytopenia and the possibility of HLH or MAS. [8]