Department of Haematology, East Surrey Hospital, Redhill, Surrey RH1 5RH, UK
Correspondence to: Dr A D B Nikapota
The combination of easy bruising and an aortic aneurysm demands special caution.
CASE HISTORY
A man of 79 was referred for investigation of thrombocytopenia. He had originally consulted his general practitioner because of spontaneous bruising and epistaxis, and his platelet count had been 81 x 109/L. 20 years earlier the patient had undergone an infrarenal abdominal aortic aneurysm repair; and the previous year, during an admission for small bowel obstruction, he had been found to have an 8 cm suprarenal abdominal aortic aneurysm (Figure 1), a 7 cm right common iliac artery aneurysm and a 7 cm right internal iliac artery aneurysm. He also had severe aortic stenosis. In view of his general frailty, the operative risks of any form of major surgery were considered too high and he was managed conservatively.
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On examination he had several bruises on the limbs but there was no lymphadenopathy or hepatosplenomegaly. Haemoglobin was 9.6 g/dL, white cell count 4.8 x 109/L, platelets 70 x 109/L. The most likely diagnosis was thought to be myelodysplasia, and to confirm this a bone marrow aspirate and biopsy was taken from the right posterior iliac crest. Haemostasis at the puncture site was achieved more slowly than usual, and later that day bleeding restarted. At that time he was discovered to be in disseminated intravascular coagulation (DIC), with the following coagulation profile: prothrombin time 17.7 s, activated partial thromboplastin 42 s, fibrinogen concentration 0.7 g/L, D-dimer assay strongly positive. Bleeding continued and before it stopped he had received 9 units of packed red cells, 2 pools of platelets, 9 units of fresh frozen plasma and 35 packs of cryoprecipitate. The patient was investigated further to establish a cause for his DIC. A routine sepsis screen was negative, and tumour markers including prostate specific antigen were normal. His chest X-ray was clear. The bone marrow aspirate and trephine biopsy revealed neither myelodysplasia nor any evidence of marrow infiltration. Therefore, in the absence of other identifiable causes of DIC, it was concluded that the patient was in chronic DIC secondary to his abdominal aortic aneurysms. Once his condition was stable he was discharged home, with a view to treating any future bleeding episodes in the same supportive way.
COMMENT
The association of DIC with abdominal aortic aneurysms is well recorded. The DIC can occur perioperatively, in relation to the release of the aortic cross-clamp1, and after dissection or rupture2. Studies with indium-111-labelled monoclonal antibody against human tissue plasminogen activator and with indium-labelled platelets have shown increased uptake within the wall of the aneurysm consistent with, respectively, increases in fibrinolytic activity3 and platelet deposition4. This continuous process is thought to account for the presence of chronic DIC in some patients with abdominal aortic aneurysms. In such cases operative repair of the aneurysm can be curative5,6.
Presenting features in our patient were spontaneous bruising and bleeding, both of which are very uncommon with a platelet count as high as 70 x 109/L. In retrospect, it would have been advisable to do a coagulation screen before the bone marrow examination, particularly in the light of the known aneurysms. Any patient with an aortic aneurysm who reports easy bruising should have a platelet count and a coagulation profile performed.
REFERENCES
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