Abscessed leiomyosarcoma of the terminal ileum

Clinical History

The patient presented with a painful mass in the right lower quadrant of the abdomen, abdominal defence and fever.

Imaging Findings

The patient presented with a history of acute abdominal pain and fever for 5 days. Physical examination revealed a painful mass in the right lower quadrant of the abdomen with abdominal defence. Laboratory tests showed an elevated white blood cell count: 10600 cell/mm3 (normal: 4600-9600 cell/mm3).

The initial radiological study performed was a CT (10-mm section thickness and 10-mm interval) following oral and intravenous administration of contrast material, which showed a mass in the right lower quadrant of the abdomen with a central low-density area, enhanced smooth wall and gas bubbles within (Fig. 1).

As a result of these imaging, laboratory and physical findings an abscess was the first suspected diagnosis and CT-guided percutaneous drainage with a 18-French catheter was performed; but pus was not obtained. The patient was taken to the operating room. Excision of the mass and part of the terminal ileum was performed.

Discussion

Neoplasms of the small intestine are relatively uncommon. Malignant spindle cell tumours represent 10-16% of small-bowel neoplasms. They arise mainly in the distal small intestine (1). These tumours have their highest frequency in the fifth and sixth decades, but cases in young patients have been reported (2-3). Diagnosis of these tumours can be a challenge for clinicians owing to their nonspecific presentation. Rarely they have an acute infectious presentation with fever, painful mass with abdominal defence and leukocytosis due to the formation of an abscess within the tumour (4).

On CT scans, spindle cell tumours are usually seen as bulky big masses situated eccentrically relative to the bowel lumen, with necrotic central areas and peripheral irregular walls. Air and/or air-fluid levels caused by cavitation may be recognised. Calcification is uncommonly seen (3).

Spindle cell tumours can undergo central liquefactive necrosis and haemorrhage and appear on images as cystic masses with irregular walls and a high-attenuation peripheral rim, corresponding to existing tumour (5). A potential problem on CT is the differentiation of these predominantly fluid-filled masses. If the soft-tissue elements and the point of attachment to the bowel are not identified and there are no features that suggest a tumoral disease (metastatic spread), a misdiagnosis of a non-neoplastic cystic mass may be falsely entertained (2).

Differential Diagnosis List

Final Diagnosis

Abscessed leiomyosarcoma of the terminal ileum

URL:	https://www.eurorad.org/case/1273
DOI:	10.1594/EURORAD/CASE.1273
ISSN:	1563-4086