Extramediastinal thymolipomas-challenges in diagnosis and dilemmas in approaches: A review

Objectives: Thymolipomas are rare tumors, usually located in the anterior mediastinum and may extend into the chest cavity. But the thymolipomas presenting solely in the chest cavity without demonstrable mediastinal mass are extremely rare. They can be termed as extramediastinal thymolipomas and they present as diagnostic and technical challenge for surgeons. Methods: We conducted a retrospective review of the pathologically proven 5 cases of thymolipomas which presented as chest cavity mass without mediastinal connection who had undergone surgical resection during last 10 years (1999 to 2008). Results: There were four women and one man with a mean age of 38.75 years. Four had unilateral and one had bilateral chest cavity tumors. Mediastinal connection of the chest cavity tumor was established in two cases by Computed Tomography (CT) scan while in one case by Magnetic Resonance Imaging (MRI). CT guided Fine Needle Aspiration Cytology was suggestive of lipoma in all five cases. In cases with established mediastinal connection, median sternotomy was done to evacuate chest cavity tumor and thymus. Mediastinal connection was noted during surgery in two cases approached through the posterolateral thoracotomy, in which complete excision of the thymus was achieved through the same incision. Conclusions: Median sternotomy approach is best in cases of biopsy proven thymolipoma irrespective of mediastinal extension demonstrated by imaging study and complete excision of the thymus should be ensured. If complete excision of thymus is not possible through thoracotomy approach on finding mediastinal extension intraoperatively, there should not be any hesitation for converting to the median sternotomy.