Morphological Information and Courses from MediaLab, Inc.

In the cytospin procedure, use a high speed centrifuge to concentrate the cells on a slide in a uniform monolayer 6 mm in diameter. The monolayer distribution enhances the morphological appearance of the cells present.Allow the slides to dry in air for several minutes and then stain them with Wright-Giemsa stain. Cytospin slides may be placed in an automatic stainer, such as Hema-Tek, or stained manually.Perform a 100 or 200 cell differential and record the number of neutrophils, eosinophils, basophils, lymphocytes, monocytes, macrophages, and blasts cells.Pathologists must review any slide which has tumor cells, unidentified cells, or immature stages of cells, such as blasts.Since criteria for review may vary from one laboratory to another, be sure to check the requirements in your laboratory before reporting the differential.

Particle smears are also made from the unanticoagulated sample. The bone marrow particles are removed from the watchglass and placed on a coverslip. One of the following items: Pasteur pipet, capillary tube or broken end of a wooden applicator stick, may be used to transfer the particles. A second coverslip is placed over the first and the particles are crushed between the coverslips as they are pulled apart. Some practice is needed to perfect this technique. As mentioned previously, this type of preparation provides a more accurate assessment of marrow architecture and cellularity than the direct smear. Morphological detail is preserved on well made slides. The remaining sample may be added to a tube containing EDTA anticoagulant and additional smears may be made if needed.

A ten-year-old boy came to a physician's attention because of recent jaundice and icteric sclerae. The immediate laboratory work revealed: Hct 24%(normal 36%-47%), MCV 79.5 fl (normal 78-95fl),RDW 13%(normal 11.5-15.0%). His blood smear findings are reflected in these photomicrographs. Note particularly the spherocytes in the upper picture. Some resemble a half-blister with the other half of the cell containing solidly-staining hemoglobin. These are called eccentrocytes. When present, they should trigger a search for red cell hereditary G-6PD deficiency and the oxidant that triggered hemolysis. These morphological findings are only clues; specific testing for G-6PD deficiency should be performed. The blue arrows in the upper photomicrograph are directed toward solid-staining spherocytes in which the cell membrane is beaded by inclusions wrapped within the cell membrane, suggesting the remains of denatured hemoglobin. Included on the smear is a target cell, several acanthocytes, a smudge cell, and a few schistocytes. The lower photomicrograph is supravital staining of affected red blood cells, verifying the presence of Heinz bodies. This disorder was first recognized during the Korean war in 10% of black American soldiers given the antimalarial drug primiquine.

This presentation will describe basic aspects of WHO III assessment. For information on details of some of the morphological assessments you will need to review information presented in the 1992 WHO III manual.Learning to do strict morphology assessments is more complicated than learning WHO III and generally requires that the technician take one of the many hands-on laboratory courses offered periodically around the country. Details of strict morphology assessment are presented in the 1999 WHO IV manual.

A Barr body appears as a small drumstick-like projection on one of the lobes of a some of the neutrophil in females. Barr bodies are attached to the nuclear lobe by a single narrow stalk which distinguishes them from other thicker projections, sometimes referred to as "clubs." Clubs have a thicker, and sometimes, a double stalk. This projection can be seen in both males and females and has no clinical significance. Barr bodies must also be distinguished from hair-like projections sometimes seen in the band form, following irradiation or in patients with a malignant tumor that has metastasized. Since Barr bodies are the morphological expression of the inactivated X chromosome, one Barr body can be seen in up to 3% of the neutrophils on a female's peripheral blood slide. In rare chromosome disorders in which three or more X chromosomes are present, two to three Barr bodies per neutrophil can be seen. Recognition of a Barr body in a neutrophil is important in order to avoid reporting it as abnormal unless two or more per neutrophil are seen.

The cytoplasmic morphological changes included in this exercise are:Dohle bodiesMay-Hegglin bodiesAuer rodsVacuolesAbnormal granulationA general term used to describe these changes is white cell inclusions.