This week’s case features a 72-year-old female patient whose routine FBC triggered an automatic manual film review due to some highly unusual red cell indices. The patient’s sample is from a neuromuscular clinic.

FBC Results:

• RBC: 4.82 x 10¹²/L
• HB: 77 g/L
• MCV: 56 fL
• MCH: 16.0
• MCHC 285 g/L
• RDW: 25.0
• PLT: 560 x 10⁹/L

Looking at the blood film, what are the cells marked with the red arrows. Given the source of the sample, what hereditary or acquired conditions may be part of your differential?

Drop your theories and observations in the comments!