Thrombotic thrombocytopenic purpura with severe hypertension in a patient with systemic sclerosis sine scleroderma and polymyositis.

We present the first documented case of thrombotic thrombocytopenic purpura (TTP) with severe hypertension complicated by polymyositis and systemic sclerosis sine scleroderma. TTP developed in the progressive phase of visceral fibrosis in the absence of skin thickening. ADAMTS13 activity was not useful for the diagnosis of TTP. Although TTP and scleroderma renal crisis (SRC) share similar findings of thrombotic microangiopathy, severe thrombocytopenia with multiple organ injuries and hemorrhagic manifestations suggested TTP rather than SRC. The patient's condition improved dramatically with plasmapheresis.