TEMPI Syndrome is an orphan disease where the person share five characteristics from which the acronym is derived: telangiectasias, elevated erythropoietin and erythrocytosis, monoclonal gammopathy, perinephric fluid collection, and intrapulmonary shunting. TEMPI Syndrome is an orphan disease where the person share five characteristics from which the acronym is derived: telangiectasias, elevated erythropoietin and erythrocytosis, monoclonal gammopathy, perinephric fluid collection, and intrapulmonary shunting. The patients were all diagnosed at middle age. The symptoms were slowly and steadily progressive. Telangiectasias developed over the face, trunk and arms. Increased serum erythropoietin levels, eventually exceeding 5000 mU /ml, preceded the intrapulmonary shunting and the development of hypoxemia. Sampling of the perinephric fluid revealed a clear, serous fluid with low levels of protein, few leukocytes and no cholesterol or triglycerides. A monoclonal gammopathy was implicated in all patients tested. Spontaneous venous thromboses occurred in some patients, sometimes accompanied with spontaneous intracranial bleeding in the absence of blood vessels malformations.