A surgical soft tissue surprise

A 56-year-old man consulted for an unchanged, painless swelling in the middle of the left fibula since fibular grafting for posttraumatic vertebral osteosynthesis 34 years ago.

No systemic symptoms or biochemical abnormalities were found.

History of left tibia plateau osteosynthesis.

Imaging work-up commenced with radiographies of the left lower leg which showed the fibular grafting site filled up with a soft tissue mass partially delineated by heterotopic ossifications (Fig. 1).

On ultrasound the soft tissue mass presented as a hetero-echogenic lesion filled with multiple small cysts and more echogenic interspersed tissue. At the edge of the lesion some foci of vascularisation were retained (Fig. 2).

For further characterisation magnetic resonance imaging (MRI) with intravenous gadolinium was performed.

MRI images showed a sharply delineated lesion with a content that was strongly T2-heterogeneous (Fig. 3a), T1-homogeneous (Fig. 3b) and not diffusion-restricted (Fig. 3c). Contrast-enhancing capsule associated with some peripheral enhancing nodules presenting fast initial enhancement followed by a plateau phase on perfusion (Fig. 3d, e).

Surrounding the lesion no pathological changes could be detected.

Background:

Textiloma, also called gossypiboma, represents a cotton matrix left behind during surgery (Fig. 4). Foreign bodies are a rare surgical complication occurring in 0.01 to 0.001% of operations, and in 80% of those cases the material left behind is a cotton matrix. 75% of textilomas are found in the abdominal cavity [1].

A textiloma can cause 2 types of foreign body reactions. Firstly an exudative response with abcedation and fistulisation. Secondly an aseptic fibrous response with encapsulation and granuloma formation [1, 2].

Clinical Perspective:

Textilomas can present as an abscess with possible fistulisation, which frequently presents shortly after surgery. On the other hand an encapsulated textiloma seldom is symptomatic, mostly depending on its location by which it sometimes presents as a chronic painless swelling. Since clinical evaluation is nonspecific in the latter case, imaging is necessary to exclude a soft tissue malignancy.

Imaging Perspective:

Radiography and computed tomography (CT) can be pathognomonic if the cotton matrix contains a radio-opaque marker [1].

A specific finding on CT is a mass with a thick contrast-enhancing wall containing spongiform air bubbles. Less frequently calcifications in the wall and mesh can be detected [2].

Ultrasound is nonspecific presenting a sharply delineated hyperechogenic lesion with heterogeneous contents and/or posterior acoustic shadowing [2].

MRI is a nonspecific technique but helpful in preoperative evaluation [3, 4]. Depending on the type of reaction, different MRI representations are possible. In an exudative response abcedation and fistulisation show a diffusion-restricted lesion with a thick contrast-enhancing wall surrounded by oedematous changes. In an aseptic fibrous response the mass presents with a thick, sharply delineated, sometimes nodular contrast-enhancing wall without surrounding soft tissue alterations. Internally the lesion is heterogeneous on T2, T1 homogeneous iso/hypo-intense and not diffusion-restricted [2].

More advanced MRI techniques such as perfusion imaging are not helpful in further characterisation but can help in distinguishing benign from malignant lesions and direct biopsy [3, 4].

Outcome:

Patients with a textiloma have a good prognosis and undergo surgery to remove the foreign body even if it’s asymptomatic due to their risk for migration and superinfection.

Take Home Message / Teaching Points:

Textilomas are rare but should be considered in postoperative patients with a chronic, aseptic soft tissue swelling.

Imaging is nonspecific in most cases, except when a radio-opaque marker is present, and thus should be closely correlated with clinical findings.

Written informed patient consent for publication has been obtained.