ARTIFACTS

• Artifacts and confusers


  Structures that closely resemble parasites but are not actually parasites
• Artifacts and confusers are found primarily in stool and blood samples
• Artifacts and confusers may be the result of disease processes, medications, and/or dietary habits
• Free-living organisms in stool caused by specimen contact with water, sewage, or soil may often cause confusion
• Artifacts and confusers may be seen on blood smears, including stain precipitate, red blood cell abnormalities, and clumping of platelets
• Other confusers include free-living amebae, flagellates, ciliates, and nematodes, as well as accidental ingestion of parasite forms in which humans are not part of their life cycle
• White blood cells (WBCs)

  • Can be mistaken for amebic cysts, especially Entamoeba histolytica
  • Have a two- to four-lobed nucleus similar to E. histolytica
  • Bands connecting the lobes are often difficult to detect
• Mononuclear WBCs (macrophages/monocytes)


  • Can resemble Entamoeba histolytica trophozoites
  • May ingest red blood cells and debris, but only macrophages ingest polymorphonuclear WBCs
  • Macrophage size range overlaps with E. histolytica but may be significantly smaller
• Pollen grains


  Resemble Taenia spp. eggs but are smaller (12-20 μm)
• Vegetable cells

  • May be confused with helminth eggs
  • Typically large and roundish oval to irregularly round in shape, up to 150 μm in size
  • Have thick cell walls and unorganized interior with large vacuoles
• Vegetable spirals

  • Resemble helminth larvae in shape and size
  • Differ from helminth larvae by lacking a head or tail region and having a ladder-like appearance
• Charcot-Leyden crystals

  Diamond-shaped crystals that develop from eosinophil breakdown products, indicating an immune response of unknown origin
• Yeast cells

  • May be confused with protozoan cysts like Entamoeba hartmanni, E. nana, and E. hominis
  • Typically show no definite internal structures, but may occasionally have small granules resembling karyosomes
  • Can be distinguished from parasites when seen in their budding stage
• Plant hair


  • May resemble helminth larvae in size and shape, but lacks diagnostic structures like a buccal cavity, esophagus, intestine, or genital primordium
• Plant material


  • May resemble helminth eggs, particularly unfertilized Ascaris lumbricoides, in size and shape
  • Typically round to oval, may or may not have a definite cell wall, and often has a rough appearance with peripheral hairs (pseudocilia)
  • Interior appears as a cluster of odd-shaped vacuoles
• Fungal elements

  • May be similar in size and shape to protozoan cysts, but lack interior structures
• Epithelial cells


  • Can resemble amebic trophozoites in size and shape, but lack typical amebic trophozoite interior structures
• Starch cells

  • May appear similar to protozoan cysts like Entamoeba hartmanni and E. nana, but lack defined internal structures and appear dark blue-black when stained with iodine
• Clumped or fused platelets


  • May be mistaken for malarial parasites, but appear in various shades of purple rather than the blue cytoplasm and red chromatin of malarial parasites
• Stain precipitate


  • May be mistaken for malarial parasites on blood smears, but is usually bluer in color and varies more in size and shape
• Red blood cell abnormalities


  • Such as Howell-Jolly bodies or Cabot's rings, can be distinguished from malarial parasites by their different staining characteristics