ENPeople reach this page with a sheet saying “immunohistochemistry recommended” and a sense that the diagnosis is somehow unfinished. It is: ordinary histology shows a tumour is there and what its cells look like; immunohistochemistry shows which proteins those cells carry on and inside them — and that decides which treatment makes sense at all.
This page covers immunohistochemistry in Germany: what is done to the tissue, which markers are read in which tumours, how long it takes, what happens when two laboratories disagree, and whether an existing paraffin block can replace a new biopsy. It is part of diagnostics in Germany.
How immunohistochemistry differs from ordinary histology
Histology shows what cells look like; immunohistochemistry, which proteins they contain. A thin tissue section is flooded with antibodies; each binds only its own protein and carries an enzyme or label that produces colour, so the pathologist sees not just cells but coloured cells — those carrying the protein. Hence the name: immuno (antibodies), histo (tissue), chemistry (colour reaction).
In practice, histology answers whether a tumour is malignant and how aggressive it looks; immunohistochemistry, where it came from and whether it carries a drug target. The same picture under the microscope means different diseases and treatments depending on the markers.
Two situations require it: a tumour of unclear origin, its metastasis found before the primary site, and the choice of drug therapy, when you must know whether the receptors a drug is built for are present. The stains use the material a biopsy takes.
Which markers are read in which tumours
Markers depend on the tumour. In breast cancer: oestrogen and progesterone receptors, HER2 and Ki-67, the measure of dividing cells. This panel splits the disease into groups receiving hormonal drugs, anti-HER2 drugs or chemotherapy; without it the conversation about treatment does not start.
In lymphomas and leukaemias, CD markers distinguish cell lineage and other proteins define the subtype. Here the markers are the diagnosis itself, not an addition: lymphoma is diagnosed by immunohistochemistry on tissue, leukaemia usually by reading them in blood or bone marrow with a related method, immunophenotyping.
Lung, bowel, stomach and prostate cancer and melanoma need markers of origin, showing which tissue a cell came from, and predictive markers: PD-L1, on which the conversation about cancer immunotherapy depends, and the MMR DNA-repair proteins, whose loss changes the plan.
An important caveat: the pathologist, not the patient with an online list, chooses the panel for the case. Extra stains do not make a report more accurate; they use up material, and a core biopsy holds little.
How the material travels through a German laboratory
The tissue is fixed in formalin and embedded in paraffin, giving a block that keeps for years; sections a few micrometres thick are cut, machine-stained to a standard protocol and read by the pathologist alongside control samples showing the staining worked that day.
The ordinary histology report usually comes first; immunohistochemical stains follow as a further document, and molecular work-up, if needed, takes longer. The laboratory states the exact interval: ask at once, as appointments and the start of treatment depend on it.
German reports tend to be detailed: pathology institutes follow medical society protocols, join external quality-control schemes and give not only “positive” or “negative” but the share of stained cells and staining intensity, because drug approvals hang on these thresholds — as the German breast cancer guideline requires.
Reviewing an earlier diagnosis: the block and slides from home
Most often a new biopsy is not needed. If tissue was taken at home, the laboratory there still holds the paraffin block, and the block, not just the paper report, is requested: new sections are cut from it and stained in Germany.
Ask your laboratory for the block or unstained sections, the finished slides, a copy of the original report and any earlier stain results. Blocks are usually released on the patient’s written request and returned; they travel at ordinary temperature, as paraffin needs no special conditions.
Reports disagree for various reasons: another antibody set, reading threshold or part of the tumour in the section, sometimes too little material from the start. This is nobody’s mistake but a reason to discuss the case again; in unclear cases a second pathologist gives a second opinion on the material.
Where the method ends and what comes next
Immunohistochemistry shows proteins, and only proteins. It does not show gene mutations, replace molecular analysis or say how the disease will behave in a particular person; “positive” means the protein is there, not that a drug will work. Some cases stay equivocal and need further methods.
An unclear HER2 result goes to FISH, which looks at the gene itself; a suspected MMR defect with unclear staining is confirmed by microsatellite instability testing; rare and advanced tumours go to gene panel sequencing. All are done on the same block, so keeping it matters more than it seems — see genetic testing. Tumour marker testing, a blood test, is completely different, though often confused with immunohistochemistry.
Frequently asked questions
How long does an immunohistochemistry report take?
Usually a few days to a few weeks, depending on how many stains are needed, whether molecular tests follow and, for a block from abroad, on shipping. The laboratory gives the exact date once the material arrives; ask for it at once.
Do I have to travel to Germany for immunohistochemistry?
Often not. The material is examined, not the patient: the block, slides and earlier reports can be sent, and the report returns in German with a translation. Travel is needed for a new biopsy, if material is insufficient, or for treatment in Germany.
How much does immunohistochemistry cost in Germany?
There is no single price: it depends on the number of stains and whether FISH or gene testing is needed. The pathologist first reviews the original report and decides on the stains; the hospital then states the cost in an estimate.
How AlenMed arranges immunohistochemistry in Germany
We ask for the original report and the block’s location, pass the case to a partner hospital’s pathology institute, agree the stains with the pathologist, arrange shipping or hand-carrying of the material and receive the report in German with a translation. Insufficient or unusable material is flagged before the trip, not after.
Plan ahead: whether you must travel at this stage (often not), which doctors will discuss the result, how long the report takes and how it reaches your doctor at home.
This material is for information only and is not an offer; a doctor decides the extent of testing and the treatment plan at an in-person consultation.