Teaching Case

Abdominal pain, haemodynamic shock, and oliguria in a 76-year-old man with history of previously treated urothelial bladder cancer, recent orthopaedic stabilization of a pathologic humeral fracture secondary to osteolytic metastasis.
Urgent laboratory tests disclosed severe blood loss (5, 5 g/dl haemoglobin) and acute kidney failure (6, 5 mg/dl serum creatinine).

Preoperatively, body multidetector CT restaging identified spine and ribs osteolytic metastases, whereas the brain, lungs, and abdominal viscera showed no abnormal findings (Fig. 1). A month earlier, oral warfarin anticoagulant therapy was started to treat atrial flutter.
At emergency admission, ultrasound (Fig. 2) identified a 7-cm hypo-anechoic collection indissociable from the spleen, without appreciable peritoneal effusion. The International Normalized Ratio (INR) was markedly elevated (7, 1 vs. therapeutic range 2-3).
Urgent MDCT (Fig. 3), acquired without intravenous contrast medium because of impaired renal function, confirmed a subcapsular splenic haematoma with characteristic mixed hyperattenuation and fluid-fluid level.
Considering the associated comorbidities, absent haemoperitoneum, the patient was treated conservatively with infusional hydration, blood transfusions, and haemodialysis. Four days later, with improved renal function, contrast-enhanced MDCT (Fig. 4) showed stable subcapsular splenic haematoma with reduced density and absent signs of active bleeding.
Clinical conditions slowly improved, leading to hospital discharge after 25 days.

Worldwide, oral anticoagulant therapy (OAT) with vitamin K antagonist warfarin is extensively prescribed. Haemorrhage is by far the major OAT-associated complication, reaching average annual rates of fatal, major, and minor occurrences of 0.6%, 3.0%, and 9.6% respectively. Risk determinants include INR target range, treatment duration, advanced age, and coexistent cerebral, cardiovascular, lung, renal, and liver diseases [1-3].
Most usually, OAT-related bleeding occurs with abnormal INR values, and involves the abdominal wall, iliopsoas, and peripheral muscles. Brain, gastrointestinal, or genitourinary tract haemorrhages may occur in patients with underlying diseases. Conversely, liver, pancreatic, and adrenal haemorrhages are exceptional [4]. A single case of splenic bleeding from heparin anticoagulation has been reported [5].
Non-traumatic abdominal haemorrhages present with abdominal pain and distension, falling haematocrit or frank hypovolemic shock, and represent a challenge for the on-call radiologist. In elderly patients, OAT-related haemorrhages are often life-threatening, reaching a 13.4% case-fatality rate. Furthermore, clinical signs and symptoms are sometimes unclear, and haematocrit does not accurately reflect the true entity of bleeding [6, 7].
Although ultrasound may readily detect acute blood collections, MDCT can image the entire body in minutes, and is the preferred imaging modality to investigate patients with suspected abdominal bleeding. The diagnosis of haematoma relies on the identification of its characteristic unenhanced CT hyperdensity. Hyperacute blood measures 40-60 Hounsfield Units (HU) attenuation secondary to high protein content, that becomes even denser (60..80 HU) from clotting within a few hours. Subsequently, haemoglobin lysis leads to the characteristic mixed-density appearance with fluid-fluid stratification ( “haematocrit sign”), that corresponds to dependent settling of denser cellular haematic components, and is highly specific of coagulopathic haematoma [4, 6]. Furthermore, CT allows confident identification or exclusion of contrast extravasation indicating active bleeding and of high-attenuation effusion consistent with haemoperitoneum [4, 8, 9]. Splenic injuries are classified as subcapsular and intraparenchymal haematomas, parenchymal and/or capsular lacerations, contusions, or fragmentation, according to the American Association for the Surgery of Trauma organ scaling injury, that is helpful for therapeutic choice [10].
Since currently low-grade splenic traumas in haemodynamically stable patients are managed conservatively, CT has a crucial role in surgical triage and monitoring of lesions. As this case exemplifies, the same applies to uncommon spontaneous splenic haemorrhages, although underlying malignancies may require splenectomy. During conservative treatment, size and CT density of haematomas decrease over time. Alternatively, spontaneous splenic ruptures are caused by infections (such as malaria, mononucleosis, or endocarditis) and haematological malignancies [11].