An 86-year-old man was referred to the emergency department with the chief complaint of difficulty in moving due to fever and general malaise. The patient had a history of pulmonary tuberculosis 40 years previously and smoking. He was taking abiraterone acetate for the treatment of prostate cancer and 5 mg prednisolone daily to prevent adrenal insufficiency. His fever had started 11 days before the visit and gradually worsened with a decrease in appetite and fatigue. The day before admission, the patient was found collapsed and immobile on the floor and was admitted to a hospital.
On admission, he was febrile, with a body temperature of 37.8 C, blood pressure of 120/60 mmHg, heart rate of 94 beats/min, and respiratory rate of 24 breaths/min. Although his oxygen saturation was 97% in ambient air, he seemed to breathe with difficulty. Chest computed tomography (CT) on admission showed patchy ground-glass opacities in the bilateral lungs (Figure 1A). Laboratory findings showed normal complete blood count profile but elevated levels of C-reactive protein at 9.91 and ferritin at 513.0 (normal, 50-200) ng/ml. Regarding the coagulation system, D-dimer level was mildly elevated at 1.8 (cut-off <1.0) mug/ml, but other data were within normal limits. The patient tested positive for COVID-19 according to polymerase chain reaction for severe acute respiratory syndrome-coronavirus-2 performed using a nasal swab.
The patient received remdesivir (200 mg loading dose on day 1, followed by 100 mg daily for 4 days) and a subcutaneous injection of 5000 units of unfractionated heparin twice daily for prophylaxis of deep vein thrombosis.
One week after admission, the patient complained of pain in his right thigh when he changed his position. The attending physician carefully repeated the physical examination and detected psoas muscle signs. The patient's haemoglobin level dropped from 13.8 to 4.5 g/dl. The patient's coagulation system status was as follows: prothrombin time-international normalized ratio was 1.47, activated partial thromboplastin time was 47.4 s, and D-dimer level was slightly elevated at 1.4 ng/ml.
Contrast-enhanced abdominal and pelvic CT revealed a massive haematoma (6.0 x 9.5 x 10.5 cm) in the right iliopsoas muscle spreading to the retroperitoneal space (Figure 1B, C). He immediately received 4 units of red blood cell transfusions. Although the radiologist considered interventional radiology to stop the bleeding, the attending physicians decided not to perform endovascular treatment considering the deterioration of respiratory condition due to pulmonary oedema caused by the transfusion.
Fortunately, the patient's vital signs were stable, and his haemoglobin level had stopped decreasing. One month later, CT showed that the haematoma had reduced in size. He started rehabilitation with a physiotherapist and was transferred to a rehabilitation hospital 2 months after haematoma onset. Throughout his hospitalization, prophylactic heparin was not readministered after haematoma development.