Clinical History
This patient was admitted with small bowel obstruction, for which she underwent laparotomy. On post-operative day 1, CT showed a large right acute retroperitoneal haematoma. A CT was done later on post-operative day 31 to look for resolution of the haematoma and an interesting finding was seen.
Imaging Findings
On post-operative day 1, axial, sagittal and coronal CT (Fig. 1 a-d) shows a large right retroperitoneal acute haematoma without any obstructive features. A repeat CT on day 31 showed an expanding chronic haematoma on the right side causing mild right hydroureteronephrosis (Fig. 2 a-d). Mild mass effect is also noted on the IVC (Fig. 2 a).
Discussion
Most acute haematomas subside without causing any serious clinical problems. However, some persist for long periods and appear clinically as slowly expanding lesions in soft tissues simulating neoplastic growth; these are called chronic expanding haematomas (CEH). CEH is a type of haematoma that is most commonly caused by trauma, post-surgical and haemorrhagic disorders. Haematomas are often reabsorbed, and gradually decrease in size. However, in rare cases, they may develop slowly and expand progressively over a period of time. CEH may persist and increase in size for more than 1 month after the initial haemorrhagic event [1].
CEH has been seen to occur in lungs [3], muscles [4], brain and least frequently in the retroperitoneal space [1]. The pathophysiology has been hypothesized to be due to blood degradation products, inducing a mild inflammatory response, which increases vascular wall permeability and bleeding from dilated capillaries in the granulation tissue beneath the capsular wall, thus resulting in the subsequent growth of the haematoma [1, 2].
The location of CEH in abdominal or thoracic cavity could be accompanied by compression to the adjacent organs and anatomical structures causing serious consequences like hydronephrosis, dyspnoea, or bone erosion when the haematoma is located in the retroperitoneal space, thorax and femur, respectively.
CEH may be difficult to differentiate from soft tissue tumours, sarcomas, actinomycosis, and inflammatory pseudotumours. If contrast enhancement is patchy within the lesion, a diagnosis of haemorrhagic sarcomas should be considered.
The treatment options for CEH is surgical excision of the haematoma together with its fibrous capsule. In the present case, the right kidney was hydronephrotic. A double J-stent may need to be placed in the right ureter to aid in identifying the ureter. Follow-up of CEH is always advised to look for recurrence.
Differential Diagnosis List
Retroperitoneal chronic expanding haematoma
Retroperitoneal soft tissue tumour
Inflammatory pseudotumour
Final Diagnosis
Retroperitoneal chronic expanding haematoma
