For example, testing for the post-transfusion RBC survival in vivo is done on a sample of healthy volunteers, and then compliance is presumed for all RBC units based on universal (GMP) processing standards (RBC survival by itself does not guarantee efficacy, but it is a necessary prerequisite for cell function, and hence serves as a regulatory proxy). Opinions vary as to the "best" way to determine transfusion efficacy in a patient in vivo. In general, there are not yet any in vitro tests to assess quality or predict efficacy for specific units of RBC blood product prior to their transfusion, though there is exploration of potentially relevant tests based on RBC membrane properties such as erythrocyte deformability and erythrocyte fragility (mechanical).Physicians have adopted a so-called "restrictive protocol" – whereby transfusion is held to a minimum – in part because of the noted uncertainties surrounding storage lesion, in addition to the very high direct and indirect costs of transfusions. However, the restrictive protocol is not an option with some especially vulnerable patients who may require the best possible efforts to rapidly restore tissue oxygenation. Although transfusions of platelets are far less numerous (relative to RBC), platelet storage lesion and resulting efficacy loss is also a concern. Other
A known relationship between intra-operative blood transfusion and cancer recurrence has been established in colorectal cancer. In lung cancer intra-operative blood transfusion has been associated with earlier recurrence of cancer, worse survival rates and poorer outcomes after lung resection.
A desmoplastic trichoepithelioma is a cutaneous condition characterized by a solitary, firm skin lesion on the face. : 672

Treatment
Desmoplastic trichoepithelioma is a benign tumour and can be managed safely with surgical removal, electrodesiccation and curettage. See also
Trichoepithelioma
Skin lesion


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