Unresectable bulky Thymic Cancer rendered operable with Radiation Therapy

Thymus cancers are rare. The standard preferred treatment has been complete resection. The role of radiation has been reserved for postoperative treatment or for palliation. Response to radiation is not well documented.  Less well defined is whether inoperable tumors can be rendered operable.

A 31-year-old woman was suffering from progressive left shoulder pain. CT scan showed bulky upper mediastinum and left supraclavicular mass. CT guided needle biopsy in September 2011 resulted in the diagnosis of thymic carcinoma. There were also adjacent adenopathy and left sided pleural based nodules. It was considered unresectable and she was treated with cisplatin and VP16. She received 6 cycles with a mild response and then progression. She was started on carboplatin and paclitaxel and with no response was referred for radiation therapy.  (Figure 1) She completed 66. 4 Gy to the bulk of the mass in May 2012 with good response with marked shrinkage 4 years later (Figure 2).  She was continued on the carboplatin and paclitaxel and received two more cycles. With the upper mediastinal mass controlled and the other disease relatively stable, she was followed. Two years post diagnosis, it appeared the pleural based masses were progressing. She was treated with 4 cycles of Carboplatin-Paclitaxel with disease stabilization. In the interim she delivered her 6^th child. On follow up in August 2016, the pleural disease appeared to be progressing. She was restarted on Carboplatin-Paclitaxel. With further progression, she returned for radiation therapy as the disease was considered unresectable. The large left posterior sulcus mass measured 8 x11x 15 cm. (Figure 3). There was other pleural based disease, but no evidence of distant metastases. The bulky posterior sulcus tumor responded dramatically (Figure 4) early in the radiation therapy treatment and the feasibility of resection was discussed with thoracic surgery. Radiation therapy was stopped at 60 Gy and she underwent thoracotomy in September 2017 with resection of the residual bulk mass and four other pleural based masses. A thorough review of this tissue and previous biopsied result in the diagnosis of WHO type B2 (with focal areas of B3) thymoma. For the remaining pleural based disease, in May 2018 she was started on Sunitinib and then switched to Premetrexed. The pleural based disease has fluctuated some in size, but overall is considered stable through June 2022 with no progression in the area of the bulky lung disease. (figure 5).