Abstract
Patients with disseminated malignancy who present with microangiopathic hemolytic anemia and thrombocytopenia may be misdiagnosed as thrombotic thrombocytopenic purpura (TTP), resulting in inappropriate plasma exchange treatment, a procedure with major risk, and delay of appropriate chemotherapy. We report the 17 year experience of The Oklahoma TTP-HUS Registry, 1989–2005, and a systematic review of previously published case reports. Ten of 335 consecutive patients in the Oklahoma Registry who were initially diagnosed with their first episode TTP and treated with plasma exchange were subsequently discovered to have disseminated malignancy; only one had a history of cancer. These 10 patients were compared to the 133 concurrent patients with idiopathic TTP.
Disseminated malignancy (n=10) Idiopathic TTP (n=133) P Data are median values. P-value for neurologic symptoms compares distribution of abnormalities. Number of patients who had ADAMTS13 measured is in parentheses. 8 idiopathic TTP patients never had plasma exchange (PE). Age (years) 56 47 0.106 Sex (% female) 30% 73% 0.008 Duration of sx (days) 21 8 0.005 Presenting sx Weakness 70% 53% 0.347 cough, dyspnea 70% 26% 0.007 Fever 50% 31% 0.292 abdominal pain 40% 35% 0.745 Nausea/vomiting 20% 53% 0.052 Neurologic abnormalities Severe 20% 47% 0.128 Minor 60% 29% None 20% 24% Laboratory data hematocrit (%) 21 22 0.868 platelet count (103/ml) 21,000 13,000 0.328 creatinine (mg/dL) 2.4 2.0 0.761 LDH (U/L) 2894 1260 0.045 ADAMTS13 Median activity (%) 50(8) 23 (81) 0.167 <5% activity (% of pts) 0 30% 0.102 Response to PE 10% 82% (125) <0.001 Death (within 30 days) 90% 20% <0.001
Patients with disseminated malignancy had a longer duration of symptoms, were more often men, had more frequent presence of respiratory symptoms, higher LDH levels, more often failed to respond to plasma exchange treatment, and had a higher mortality. Neurologic abnormalities, hematocrit, platelet count, and serum creatinine were not different between the two groups. Diagnosis of malignancy was made by bone marrow biopsy in 6 patients but not until autopsy in 2 patients. A systematic review identified 19 additional patients, reported from 1965 to 2005, in whom TTP or HUS was initially suspected and systemic malignancy subsequently discovered. Only 5 patients had a history of cancer. Malignancy was not diagnosed until autopsy in 6 patients. Fourteen different malignant disorders were diagnosed in these 29 patients.
CONCLUSIONS: Disseminated malignancy may be occult and may mimic TTP. A search for systemic malignancy, including a bone marrow biopsy, is appropriate when patients diagnosed with TTP have atypical clinical features or fail to respond to plasma exchange.
Exudative Retinal Detachment Treatment in a Patient with Thrombotic Thrombocytopenic Purpura