Which of the following conditions is detectable only by examination of a peripheral blood film?

The condition detectable solely by examination of a peripheral blood film is poikilocytosis. Poikilocytosis refers to the presence of irregularly shaped red blood cells in the bloodstream, which can have varying shapes and sizes. This phenomenon can only be visualized under a microscope when examining the blood smear. While the other conditions—microcytosis, anisocytosis, and hypochromia—can also be observed in a blood film, they are often assessed and quantified using automated analyzers, which measure red blood cell size, distribution, and hemoglobin content.

Detecting poikilocytosis specifically requires the detailed examination of the peripheral blood film itself, where the morphology of individual red blood cells can reveal significant abnormalities associated with different underlying pathological conditions, such as certain anemias and bone marrow disorders. Hence, for isolation and clear identification, poikilocytosis stands out as a condition uniquely recognized when examining a peripheral blood film directly.