When sending tissue samples for histopathological and immunohistological examination, the following points must be observed:

  • artefact-free sampling of a typical lesion of sufficient size (diameter > 05 cm)
  • immediate fixation (4% formaldehyde ≙ 10% formalin)
  • preparation of an anamnesis including diagnostic task and clinical picture
  • shipment in a suitable container (available from us free of charge)
  • Immunohistochemistry can always be done after histopathology with the material supplied.
Detailed explanations:

As a sample, a representative piece of tissue free of preparation artefacts (e. g. disruption, squashing, electrocoagulation) should be taken. The diameter of the sample should not be less than 0.5 cm. An exception to this are samples which, for technical reasons, cannot be obtained otherwise (such as endoscopically taken stomach biopsies). Furthermore, it should be borne in mind that samples which are too small only provide little information, whereas samples that are too large cannot be fixed properly. Pieces of tissue with an edge length of 1 cm are recommended. However, this might vary depending on the lesion to be examined, the sampling site and the objective.

Small lesions should be placed centrally so they are not overlooked and thus truncated during preparation. If in doubt, several samples should be collected.

Skin punch

Skin punch

As skin samples, punch biopsies of all dermal layers with a diameter ≥ 0.6 cm are to be submitted. Primary lesions from several locations should be selected. The biopsied area should not be pre-treated by scraping or shaving. The anamnesis should contain all relevant data which might be important for the diagnosis. It is recommended to use our submission form Pathology, which especially focuses on skin and tumour diagnostics, but also leaves room for any other type of anamnesis.

Cytology

Cytology

Samples can primarily be taken by wipe test, scraping or puncture (with or without aspiration). The most common technique is the fine needle aspiration, using a thin hollow needle (G22 – G 27) attached to a syringe. A vacuum is created and, if possible, the tissue should be punctured several times in different directions. Before detaching the needle, the vacuum must be released to avoid the material receding into the syringe. The material obtained is then pressed out of the needle onto the side of a glass slide. A second slide is placed flat at a right angle on top of the first one and is then carefully pulled away across the slide. If the sample is more liquid, a steeper angle (45°) – like in a blood smear – should be applied.

For the cytological examination of puncture fluids, excretions or secretions, the fluids obtained are centrifuged at 2500-3000 rpm for three to five minutes. The supernatant is decanted and the sediment is carefully spread like a blood smear and shipped air-dried. Please indicate on the submission form whether it is a sediment smear or a native smear. If the puncture fluids are sent directly, EDTA tubes should be used as test vessels.

For bronchial, conjunctival and vaginal cytology, the swab obtained (cytobrush) should be rolled onto a glass slide, not smeared.

All smears should generally be sent in air-dried, but unfixed. If desired, the smears can already be stained at the practice (please note: do not use a cover glass). The most important point is to create a thin smear consisting of only one layer (monolayer). The most common reason for getting a limited quality up to not being able to assess at all are smears that are too thick.