Teaching Case

A 28-year-old woman presented with vague lower abdominal pain, discomfort and swelling in the right iliac fossa which has gradually increased. She had a history of cesarean section 3 years ago. On physical examination, she had a rounded palpable mass in right iliac fossa.

Abdominal ultrasound and x-rays were performed with the provisional diagnosis of perforated appendix with lump formation.

Ultrasound showed a well-defined complex hypoechoic mass with multiple linear hyperechoic foci and major posterior acoustic shadowing. No vascularity was seen on colour doppler imaging (Fig. 1).

X-rays abdomen showed a soft tissue density mass in the right iliac fossa and a curvilinear metallic object within this mass (Fig. 2).

CT scan images showed a heterogeneous mass with a metallic wire in the right iliac fossa adherent to the adjacent small bowel loops. Prominent mesenteric nodes were also seen adjacent to the mass (Fig. 3a, b, c).

On the basis of these findings, the patient underwent surgery and a retained a piece of gauze was found which was adherent to distal ileal loops.

Gossypibomas are usually encountered after abdominal surgery, especially in emergency cases where multiple surgical teams are involved. [1] Although surgical teams take a number of precautions to avoid these unusual postoperative complications like counting the sponges and gauze pieces after surgery and using sponges and gauze pieces with radio-opaque wires or markers [2]. Nevertheless, it still happens in the incidence of 0.15-0.2% and is one of the common cause of malpractice claims. [3, 4]

The pathophysiology behind the formation of this mass is an aseptic and/or exudative type of inflammatory reactions. The former type causes fibroblastic reaction by encapsulation of foreign body and granuloma formation and the later type causes abscess formation which may be secondary to bacterial infection. [5] Patients having such masses present with very nonspecific symptoms like pain, fever, lump formation and the delaymay also greatly vary from immediate postoperative period to several years later.

The diagnosis of gossypiboma is challenging because it can resemble a benign or malignant tumour [6]. The imaging features of Gossypibomas are also not very specific. Reaching the correct diagnosis may require multi-modality approach and correlation with history. Gossypibomas appear as soft tissue mass on plain X-rays, however, the most important finding is the metallic wire. With Ultrasound, it appears as a complex hypoechoic or cystic mass with wavy internal hyperechoic material, with major posterior shadowing.  On CT  it appears as a well-defined mass of heterogeneous attenuation with or without foci of air, wall enhancement after iodine injection, calcification and metallic density object within it. There may be adjacent perilesional inflammatory changes and abscess formation. MRI does not give additional information but can be performed when other modalities have failed. On MRI it appears as complex cystic area with low signal capsule and containing serpiginous linear areas of intermediate signal intensity. [5]

Gossypibomas can be associated with many complications like formation of abscessesand bowel adhesions with a risk of obstruction and fistula formation. [5] It is therefore very important to rule out this diagnosis specifically in patients who present with abdominal pain, infection or lump with a history of surgery. Surgical removal of the foreign body should be performed.