Giant Mobile Intraperitoneal Loose Body

Case Report

A 70-year-old man presented to our institute with chief concerns of vague intermittent abdominal pain, predominantly in the hypogastrium, and occasional history of constipation. The pain was gradual in onset, dull in nature, and nonradiating, with a duration of 4–5 weeks. There was no history of fever. The blood pressure, pulse rate, and body temperature were within normal limits. On local examination, there was no tenderness in the abdomen. A large, hard intra-abdominal mobile lump was felt on deep palpation in the hypogastric region. The complete blood count and coagulation profile were within normal limits.

Abdominal ultrasonography revealed a large, predominantly calcified, mobile lesion in the pelvis with a central hyperechoic dense, calcific focus and surrounding alternate soft-tissue area (Figure 1). The lesion was separate from all the intraperitoneal viscera, with a well-maintained interface with the surrounding structures. Abdominal computed tomography (CT) was performed, which revealed a large, well-defined round to oval soft-tissue mass in the pelvis at the L-5 vertebral level with dense central calcification surrounded by lamellated soft tissue, measuring 10.2 × 8.3 × 8.1 cm. The mass had a well-maintained interface with surrounding fat planes (Figure 2).

Figure 1.

Sonographic image showing a large predominantly hypoechoic lesion with central hyperechoic calcific focus.

Figure 2.

(A) Sagittal and (B) axial images of abdominal computed tomography showing a large lesion with a dense calcified core (“C”) with lamellated surrounding soft tissue (arrows) with the upper margin at the L-5 vertebral level. Maintained fat planes are also seen in the axial image.

Another CT scan was performed after 11 days. The scan revealed that the mass had changed its position and descended in the pelvis below the L-5 vertebral level (Figure 3). All other features remained the same, thus confirming the mobile nature of the mass. With the clinical, sonographic, and CT evidence, the diagnosis of a large mobile intraperitoneal loose body was formulated. The patient underwent exploratory laparotomy, and the loose body was removed. He is currently free of symptoms.

Figure 3.

Sagittal view of abdominal computed tomography taken 11 days after the initial scan showing the same mass with the calcified core (“C” note) and surrounding soft tissue (arrows), but the position of the mass is well within the pelvis below the L-5 vertebral level.

The formation of the peritoneal loose bodies is due to the transformation of torsed, infarcted, and detached epiploic appendages that transform into fibrotic masses.¹ They are usually small, ranging from few millimeters to few centimeters, and detected incidentally during laparotomy for other reasons. Gayer et al. described a case of a 3-cm, round, mobile intraperitoneal loose body.² In another report, Kim et al. described a case of giant peritoneal loose body measuring 7.5 × 7.0 × 6.8 cm.³ The largest peritoneal loose body measured 95 × 86 mm and was reported by Mohri et al.⁴ Large loose bodies in the peritoneum are a rare entity with only a few documented cases.

The typical CT appearance is concentric, oval or round well-defined mass with central calcification surrounded by peripheral soft tissue as seen in the present case. The differential diagnosis of a pelvic mass with central calcification on CT will either be a retained sponge or a loose body.² As there was no history of previous surgery in this patient, so the possibility of a retained sponge was excluded.

The purpose of this article is to make clinicians and radiologists aware of this rare occurrence and its typical CT appearance. These giant bodies need to be removed even if they are asymptomatic because of their ability to cause pressure symptoms on surrounding viscera. They can be followed with serial imaging if small.

Disclosures

Author Contributions: M. Ilyas and M. Wani wrote and edited the manuscript. M.A. Dar and F.A. Shaheen edited the manuscript. M. Ilyas is the article guarantor.

Financial disclosure: None to report.

Informed consent was obtained for this case report.