Red blood cell abnormalities
Microcyte
Description
Ø < 7 µm, in the smear smaller
diameter than the nucleus of a
small lymphocyte, often
hypochromic
Incidence
Iron deficiency
Megalocyte
Description
Large red blood cell, oval shape,
no central pallor, always hyper-
chromic
Incidence
Vitamin B12 or
folate deficiency
Macrocyte
Description
Large red blood cell, Ø 10 µm,
central pallor present
Incidence
Reticulocytes are always
macrocytes and reflect the
regeneration of erythropoiesis.
Microspherocyte
Description
Small red blood cell, Ø < 6 µm,
normal volume, no central
pallor
Incidence
Hereditary spherocytosis
Polychromatic red blood cell
Description
Blue-tinged red blood cell with
remnants of diffusely distributed
RNA, often macrocytic
Incidence
Reticulocytosis, unspecific with
severe anaemia
Echinocyte
Description
Crenated red cell with evenly
distributed and uniformly sized
spicules
Incidence
Artefact. In vitro phenomenon
and in vivo with acidosis and
pH hyperosmolarity
Acanthocyte
Description
Membrane spikes of irregular
size, unevenly distributed
Incidence
Hepatopathy,
post splenectomy
Sickle cell
Description
Red blood cell with pointed
ends, usually crescent shape,
apparently hyperchromic
Incidence
In peripheral blood only observed
with homozygous HbS disease,
sickling in heterozygous disease
only under oxygen deficiency in
cell suspension
Pincered cell
Description
Mushroom-shaped red blood
cell, no central pallor
Incidence
Hereditary spherocytosis,
band 3 gene defect,
MCHC > 36 g/dL
Elliptocyte (ovalocyte)
Description
Elongated shape with round
ends, normal central pallor
Incidence
Hereditary elliptocytosis,
two types: haemolytic, non-
haemolytic
Teardrop cell
Description
Teardrop or pear shape
Incidence
Extramedullary haematopoiesis
with primary myelofibrosis
Pappenheimer body
Description
Dark blue, granular, mostly
irregularly shaped, solitary or
multiple inclusions found at cell
periphery, Ø max. 1 µm, frequently
associated with HowellJolly
bodies, biochemically: iron
protein complexes
Incidence
Post splenectomy
Cabot ring
Description
Round to oval or loop-like,
fine, red-purple inclusion;
point of origin: remnants of
mitotic spindle
Incidence
Unspecific, with severe
anaemia, e. g. thalassaemia
Howell-Jolly body
Description
Round residual nucleus of
purple-brown colour, circular,
not refractive, eccentrically
placed, frequently associated
with acanthocytes, target cells,
Pappen­heimer bodies
Incidence
Post splenectomy, severe anaemia
with intact spleen function,
e. g. pernicious anaemia, MDS
Sysmex Europe GmbH
Bornbarch 1, 22848 Norderstedt, Germany · Phone +49 40 52726-0 · Fax +49 40 52726-100 · info@sysmex-europe.com · www.sysmex-europe.com
In cooperation with:
Universitätsklinikum Aachen Klinik für Hämatologie, Onkologie, Hämostaseologie und Stammzelltransplantation
Pauwelsstraße 30, 52074 Aachen, Germany · Phone +49 241 80-0 · info@ukaachen.de · www.ukaachen.de
You will find your local Sysmex representative’s address under www.sysmex-europe.com/contacts
Abbreviations: Ø – diameter, RNA – ribonucleic acid, DNA – deoxyribonucleic acid, MDS – myelodysplastic syndrome, AML – acute myeloid leukaemia, BM – bone marrow, Hb – haemoglobin, WBC – white blood cells
© Copyright 2015 – Universitätsklinikum Aachen AÖR, Klinik für Hämatologie, Onkologie, Hämostaseologie und Stammzelltransplantation
Authors: Reinhild Herwartz, Prof. Dr. med. Roland Fuchs, Medizinische Klinik IV, Uniklinik RWTH Aachen
ZE000791.EN.N.10/15
Hypochromic red blood cell
Description
Central pallor > 1/3 of the cell
surface, often microcytic
Incidence
Iron deficiency anaemia
Stomatocyte
Description
Central pallor appears slit-like,
straight or mouth-like
Incidence
Hepatopathy, hereditary
stomatocytosis
Anulocyte
Description
Pronouncedly hypochromic red
blood cell with small, peripheral
ring of haemoglobin, always
hypochromic
Incidence
Iron deficiency anaemia
Fragmented red cell
Target cell
Description
Round, central Hb concentration
due to dome-shaped hernia of
the membrane, followed by an
empty zone, then peripheral Hb
ring
Incidence
Thalassaemia, post splenectomy
Basophilic stippling
Description
Numerous small, coarse, blue
granules, unevenly distributed,
due to denatured ribosomes
(RNA)
Incidence
Unspecific in severe anaemia,
especially with MDS, AML –
especially in FAB AML-M6, pernicious
anaemia, lead poisoning,
hereditary pyrimidine 5'-nucleotidase
deficiency
as seen with May-Grünwald-Giemsa (MGG) staining
Erythroblast
Description
Erythroblasts (E) in peripheral
blood of adults are always pathological
(physiological only in
first month of life). In the blood
smear, E are not included in WBC
differential but counted on top
per 100 WBC.
Incidence
Associated with diseases showing
increased erythro- and haematopoiesis
and in extramedullary
haematopoiesis
Normocytic red blood cell
Description
Diameter: 7 µm, equals the
diameter of the nucleus of a
small lymphocyte. Colour:
haemoglobin colour (pink – red);
shape: round or oval, central
pallor 1/3 of the cell surface;
no inclusions.
Incidence
Physiological red blood cell
Rouleaux
Description
Linear arrangement of red
blood cells simulating a ‘stack
of coins’
Incidence
Hypergammaglobulinaemia,
monoclonal and polyclonal,
hyperfibrinogenaemia
Plasmodium falciparum inclusions
Description
Ring type: brown nucleole, ringshaped
blue cytoplasm, infested
red blood cell not enlarged, no
granulation or pigmentation,
multiple parasites common
Incidence
Malaria tropica, > 5 % parasite
infestation = severe malaria
tropica. Plasmodium falciparum
must be detected in the blood
smear!
Description
Red blood cell with intact convex
and damaged concave side,
pointed ends let the cell appear
as helmet cell
Incidence
Red blood cell fragmentation
syndrome, findings of ≥ 5 ‰ and
marked thrombocytopenia can
point to thrombotic-thrombocytopenic
purpura (TTP). This result
is a lab emergency and should be
communicated by phone.