Section 2 Atypia

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• Section 2 Atypia

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• Definition this refers to the extent to which
  tumor cells different from their origin normal
  cells.
• obviously poor differentiation, malignant
• slightly well differentiation, benign

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• 1. Atypia of tumor tissue structure
• benign tumor slightly change in pattern,
  including structure
• malignant tumor obviously, disorder
• arrangement, direction, cell layers, and cell
  rank order.

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• 2. Atypia of tumor cells
• Benign tumor slightly
• Malignant tumor obviously
• (1) Pleomorphism of tumor cells
• Variation in size and shape
• Some extremely small and primitive appearing
• Some many times larger than their neighbors, even
  tumor giant cells

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• (2) Pleomorphism of nuclei
• ? Large nuclear the nuclear to cytoplasmic
• ratio may approach 11 (the normal 146)
• ? Hyperchromatic dark staining (containing
• abundance of DNA)
• ? Sometimes have two nuclei, even multi
• nuclei giant cell.
• ? The nuclear shape is usually variable.

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• ? Numerous mitoses
• the most important is appear atypical, bizarre
  mitotic figures as non- symmetry, tripolar,
  quadripolar, multipolar spindles and abortion
  types pathologic mitoses.
• ? Nuclear membrane became thick
• the chromatin is often coarsely clumped
• ? Large nucleoli

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(3) Changes in cytoplasm Basophilic
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Atypia (Quoted from RubbinsBasic Pathology)
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non- symmetry, tripolar, quadripolar, multipolar
spindles and abortion types pathologic mitoses.
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non- symmetry(left), tripolar(middle), and
abortion types(right) of pathologic mitoses.
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• 3. Atypia of tumor ultrastructure
• The difference mainly in quantity compared
  with normal cells
• (1) Large nuclei and nucleoli, irregular shape,
  and multiply.
• (2) Heterochromatin increase, coarsely clumped
  and distributed along the nuclear membrane.
• (3) Mitochondrion, endoplasmic reticulum, and
• Golgi complex hypogenesis, abnormal shape and
  decreased number.

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• (4) More dissociative nuclein
• (5) More lysosomes
• (6) The cellular junction decrease
• (7) Microvillus variation in shape, number, and
  arrange mount