Spherocytes: loss of central pallor

Spherocytes are spherical red cells appearing round and dense on a blood film. They may accompany haemolysis from different mechanisms.

Choose a region without overlapping red cells. Compare size, staining and central pallor with neighbouring cells; inspect several fields.

Several red cells are small, deeply pink and lack visible central pallor. Others retain a pale central area.

Hereditary spherocytosis and some immune haemolytic processes are possible causes. Family history, examination and immunohaematological testing guide assessment.

A thick part of the film may obscure central pallor. Red-cell fragments have more irregular outlines and should not be mistaken for spherocytes.

Assess reticulocytosis, increased indirect bilirubin and LDH, reduced haptoglobin and splenomegaly. An EMA test can help when a membrane disorder is suspected.

Poorly tolerated anaemia, a rapid haemoglobin fall or acute deterioration requires prompt assessment regardless of the number of visible spherocytes.

A negative direct antiglobulin test alone does not prove an inherited disorder. The source description does not establish a final aetiology.

Recognise the morphology, establish whether haemolysis is present, then distinguish an acquired cause from an inherited abnormality.

• Bolton-Maggs et al. — Hereditary spherocytosis, BCSH guideline (2011 update) ↗
• Ed Uthman — document iconographique original / original image ↗

Documentary review: 2026-10-16