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

Background. Sickle trait affects approximately 8% of the black population i n the United States and up to 40% of individuals in some parts of tropical Africa, but rarely causes clinically significant illness. This report provi des the first conclusive evidence that erythrocytes in patients with sickle trait may sickle in the microvasculature of solid tumors, leading to impai red perfusion and hypoxia. Case. A black woman who was sickle trait positive presented with stage IIIB squamous cell carcinoma of the cervix. A biopsy showed extensive intravasc ular 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 indiv idual oxygen reading <5 nim Hg. Conclusions. Erythrocytes in patients with sickle trait may sickle in the m icrovasculature of solid tumors and contribute to reduced blood flow and th e development of hypoxia. Hypoxia is a strong independent prognostic factor in patients with cervix cancer, and further study is needed to evaluate th e impact of intratumoral sickling on long-term outcome. (C) 2001 Academic P ress.