Micro-spherocyte

Severe membrane defects (e.g. hereditary pyropoikilocytosis). Toxin induced membrane damage: particularly Clostridium perfringens. Infrequent microspherocytes may appear as part of a spectrum of cells in many conditions with erythrocyte damage (e.g. fragmentation) or fragile production (e.g. megaloblastic states).

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Inherited defects

Severe membrane defects (e.g. hereditary pyropoikilocytosis)

Acquired causes with frequent microspherocytes

Direct physical damage to the erythrocyte membrane: burns or heated sample
Toxin induced membrane damage: particularly Clostridium perfringens

Acquired causes with infrequent microspherocytes

Infrequent microspherocytes may appear as part of a spectrum of cells in many conditions with erythrocyte damage (e.g. fragmentation) or fragile production (e.g. megaloblastic states)