Calcified multilocular thymic cyst associated with thymoma: a case report

There are few case reports of thymoma with a thymic cyst. Such an association renders it difficult for any pathologist to differentiate from other neoplasms, such as a cystic thymoma.

A 50-year-old Berber woman from Morocco was admitted with a chronic cough of more than 10 years duration. Her medical history and physical examination were normal. Anterior chest radiography demonstrated a calcified opacity in her right anterior mediastinum. A chest-computed tomogram revealed a round cystic tumor, with significant calcification in her right anterior mediastinum. A surgical exploration was performed. The tumor seemed to be a well-encapsulated and totally calcified lesion, arising from the right lobe of her thymus. It was removed by partial resection of her thymus. Through histology, the calcified tumor exhibited some areas of multilocular fibrous-wall cysts. These cysts were partially lined by small cuboidal cells with severe chronic inflammation and an AB thymoma that arose from the wall of the cyst.

Greater attention should be given to multilocular thymic cysts, to exclude the possibility of neoplasm, especially when the cyst wall is thickened.