Intratumoral sickling in a patient with cervix cancer and sickle trait: effect on blood flow and oxygenation

Sickle trait affects approximately 8% of the black population in the United States and up to 40% of individuals in some parts of tropical Africa, but rarely causes clinically significant illness. This report provides the first conclusive evidence that erythrocytes in patients with sickle trait may sickle in the microvasculature of solid tumors, leading to impaired perfusion and hypoxia.

A black woman who was sickle trait positive presented with stage IIIB squamous cell carcinoma of the cervix. A biopsy showed extensive intravascular sickling of erythrocytes. An aspirate of blood obtained directly from the tumor also showed numerous sickled cells. A peripheral blood smear was normal. Direct measurement of oxygen tension using the Eppendorf electrode revealed the tumor to be markedly hypoxic, with 93% of a total of 142 individual oxygen reading <5 mm Hg.

Erythrocytes in patients with sickle trait may sickle in the microvasculature of solid tumors and contribute to reduced blood flow and the development of hypoxia. Hypoxia is a strong independent prognostic factor in patients with cervix cancer, and further study is needed to evaluate the impact of intratumoral sickling on long-term outcome.