Mediastinal lymphangioma in adults: CT and MR imaging features

Adult mediastinal lymphangiomas are rare lesions the diagnosis of which is difficult based on imaging studies. A retrospective study of CT, MR, and pa thologic findings of mediastinal lymphangioma was performed in order to cor relate pathological and imaging findings. Nine cases of adult lymphangiomas were identified in the records of our institution over a 12-year period. T he CT, MR, and pathologic findings were reviewed. Lesions were classified p athologically as unilocular, cavernous, and intermediate types. Pathologic examination identified six cases of unilocular lesion, two cases of caverno us type, and one intermediate type. The CT features (n = 9) included a smoo thly marginated non-enhancing mass of water attenuation (n = 7), a non-enha ncing mass of soft tissue attenuation (n = 1), and an enhancing multiseptat ed mass (n = 1). Lesions were located in the anterior mediastinum (n = 2), right paratracheal (n = 4), subcarinal (n = 1), aortopulmonic window (n = 1 ) areas, and below the left hilum extending into the posterior mediastinum (n = 1). The MR features (n = 3) were characterized by an enhancing multicy stic and multiseptated appearance, evocative of a cavernous type in two cas es. The CT appearance of mediastinal thoracic lymphangioma is variable depe nding on the pathologic type. The most common uniocular type is a non-enhan cing thin-walled mass on CT. A less frequent cavernous type can be suggeste d based on a multiseptated and loculated mass on CT and/or MR examination.