News : 2017 : January

Case of the Month: Under the Microscope

Prominent Erythroid Regeneration in an Anemic Green Turtle (Chelonia mydas) from Adjunct Professor Dr. Nicole Stacy.

Clinical history: This wild green turtle stranded and presented with lethargy, hypoglycemia, and nonregenerative anemia. After 21 days of supportive therapy, the turtle developed an adequate erythroid regenerative response. The response was progressive with day 0 PCV of 16%. On day 7, the PCV was 14%, day 14 – 19%, day 21 – 25%, day 28 – 27%, and day 45 – 33%.

Blood film evaluation at day 14 – erythrocyte morphology comment: There is a prominent regenerative response characterized by marked anisocytosis and polychromasia, frequent basophilic stippling, occasional mitotic figures, and infrequent early stage erythroid precursors with synchronous maturation from rubriblast to mature erythrocyte, consistent with an adequate regenerative response.


Figure 1: Image composite of the blood film from day 14 with PCV 19%: early stage precursors with synchronous maturation to mature erythrocytes, binucleation, mitotic figure, marked anisocytosis and polychromasia, basophilic stippling.


Figure 2: Blood film from day 45 with PCV 33%: mature erythrocytes with mildly increased anisocytosis and polychromasia and frequent basophilic stippling.

The green turtle fully recovered by day 45 and was successfully released back into the wild.

Key points:

Erythroid regeneration in reptiles can be prominent and early stage precursors may be observed in the peripheral blood. These round early stage precursors need to be identified correctly in the hemocytometer and by blood film evaluation, since they may be misinterpreted as lymphocytes or as leukemic cells of lymphoid, myeloid, or erythroid origin. These morphologic changes in the erythroid cell line are best interpreted in context of other hematological and biochemical data as well as clinical findings.