Artifacts in Histological Preparations

Microwave heating It’s a kind of low power energy carried by micro-waves Internal direct heating is our advantage It’s a physical effect, neither chemical nor magical

Perception Reality Microwaves cook my samplesMicrowaves create physical heat like conventionals do, but internally in the tissues. Better homogenity & efficiency. Rapid processing = poor morphology Today’s technology makes hours an inefficient use of time. Quality is guaranteed priority. Antigens will be lost foreverDiagnostic equivalence is validated by studies showing optimal antigen reactivity. Molecular studies are not possibleMicrowave do not affect DNA, RNA and proteins’ quality at all. Day processing is uselessDay processing = same day diagnosis = patient centric care

1.Samples Preparation Artifacts

Heat Damage Fig.1 Breast biopsy Damage from laser-generated heat or over-heated wax or while drying slides: loss of nuclear and cytoplasmic detail connective tissue fibers become coagulated

Crush Artifact Fig.2 Section of lymph node Damage from crushing by forceps or other surgical instruments: darkly staining distorted cell nuclei some stretching and flattening of tissue

Postmortem Change Fig.3 Section of liver Autolysis for delay of fixation: poorly defined nuclei imprecise cytoplasmic staining

Specimen Marking Dyes Fig.4 Skin biopsy Excision margins marked with coloring agents: not natural color of the margins possible penetration into the tissue

2.Fixation Artifacts

Zonal Fixation Fig.5 Section of liver Different degrees of fixation at different levels within the specimen: insufficient time in fixative specimen too large reagent with poor penetration rate

Streaming Artifact Fig.6 Section of liver Precipitation and displacement of glycogen by an advancing fixation front

Formalin Pigment Fig.7 Red cells in a section of kidney Reaction of non-buffered (pH acid) formalin with hemoglobin: pigment as a brown to black associated with red blood cells

Mercury Pigment Fig.8 Section of kidney Fixation in mercuric chloride-containing fixatives: random brown to black granular deposits

3.Tissue-Processing Artifacts

Vessel Shrinkage Fig.9 Section of brain stem Poor brain fixation: perivascular shrinkage membrane separation

Poor Processing Fig.10 Breast specimen Inadequate fixation, too short processing cycle, inappropriate or exhausted reagents, mechanical fault with the processor, wrong replacement of solvents: extensive loss of architectural detail and clarity disruption within loose connective tissue

Imcomplete Dehydration Fig.11 Gastrointestinal biopsy Incomplete dehydration during processing: loss of nuclei details cloudy appearance of sections

Under Decalcification Fig.12 Section of bone Inadequate decalcification: appearance of dark blue areas with hematoxylin in the trabeculae

Over Decalcification Fig.13 Sections of bone Excessive decalcification: loss of all nuclear detail distruction of tissue morphology

4.Staining Artifacts

Residual Wax Fig.14 Section of skin Incorrect dewaxing prevents solutions penetration: presence of areas totally absent of stain

Incomplete Staining Fig.15 Section of liver Inadequately filled staining dish: absence of stain in some area of the section

Nuclei Not Crisp Fig.16 Section of skin Incomplete fixation or residual water after dehydration: “smudgy” or not crisp nuclei no distinct chromatin patterns

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