We report the case of a 48-year-old woman with a long-standing history of irritative cough and problems swallowing, in whom a computed tomography scan showed an incidental of a retrotracheal and right paraesophageal cystic mass measuring 2.5 cm, which shifted the esophagus slightly to the left, consistent with bronchogenic cyst, schwannoma, or esophageal duplication cyst. It was excised using right single-port video-assisted thoracic surgery (VATS). Histology study revealed several cystic formations covered by a flattened, cuboidal and cylindrical ciliated epithelium over a fibrous stroma, that showed immunohistochemical positivity for estrogen receptors (ER), progesterone receptors (PR), and Wilms tumor protein (WT1) (Fig. 1).
A) Computd axial tomography showing a cystic lesion measuring 2.5 cm located in the posterior mediastinum. B) Cystic formation of thin walls on a fibrous stroma coated with a single layer of epithelial cells. C) Detail of the non-stratified ciliated cylindrical epithelium covering the cyst (H&E; B: ×40, C: ×400). D) Coating epithelium shows positive immunostaining for WT1, progesterone receptors (E) and estrogen receptors (F) (D-F: ×100).
The presence of a cyst of Müllerian origin in the posterior mediastinum was first described by Hattori in 2005, but their origin is still unknown and these are rare lesions with few described cases1. They usually occur in perimenopausal women and have been associated with obesity, gynecological history, and hormone replacement therapy. They follow a benign course without recurrence. Müllerian cyst or Hattori cyst should be included in the differential diagnosis of posterior mediastinal cysts, and histologic and immunohistochemical studies are essential for diagnosis, since they can easily be confused with bronchogenic cysts2.
Please cite this article as: Barona García L, Ruiz Maciá JA. Quiste mediastínico de origen mülleriano: importancia del estudio inmunohistoquímico. Arch Bronconeumol. 2021;57:766.
