Statistics from Altmetric.com
We read with great interest the well-written review by Kunst et al1 discussing parasitic lung infections. In the section on hydatid disease (HD), the authors report that chest scans may reveal diagnostic features including collapse of the laminated membrane from the surrounding host tissue, the presence of daughter cysts and the presence of cyst rupture. We wish to highlight an important diagnostic challenge: differentiating between the typical tomographical presentations of HD and textilomas. Recently, Miguélez-Vara and Mariñan Gorospe2 reported this problem, describing their difficulty in establishing a differential diagnosis between an HD recurrence and a complication of surgery (textiloma).
We report the case of a 47-year-old woman presenting with cough and chest pain and a thoracic mass detected during a radiological examination. A CT scan showed an encapsulated mass containing high-density opacities (figure 1). The patient lives in an area of endemic HD and had a history of surgery to remove a mediastinal tumour 16 years earlier for a mass of unknown histological type. The initial hypothesis for the present mass was a hydatid cyst, but surgical resection demonstrated a textiloma.
A textiloma is a mass composed of a retained surgical sponge or gauze surrounded by a foreign body reaction.3 4 Such foreign bodies can often mimic tumours or abscesses either clinically or radiologically.4 Textilomas generally show a high-density capsule and their contents may present an enfolded pattern, with wavy, striped high-density areas that represent the sponge.3 4 This is very similar to observations of hydatid cysts. In HD, the detached membrane inside the cyst may be seen as a twisted, undulated structure, with a snake-like appearance, called the snake (or serpent) sign.5
Therefore, both conditions can present as encapsulated cysts containing a high-density undulated structure that corresponds to the sponge of a textiloma or to the detached inner membrane of a hydatid cyst. These conditions may be indistinguishable on CT, and differential diagnosis may be made by correlation with clinical features. In some cases, diagnosis may be made only after surgery.2
Competing interests None
Provenance and peer review Not commissioned; not externally peer reviewed.