SESSION TITLE: Disorders of the Mediastinum Student/Resident Case Report Posters
SESSION TYPE: Student/Resident Case Report Poster
PRESENTED ON: Tuesday, October 27, 2015 at 01:30 PM - 02:30 PM
INTRODUCTION: Thymoma is the most common anterior mediastinal tumor arising from thymic epithelial cells. One-third to one-half of patients with thymoma are asymptomatic and incidentally detected on routine x-ray. Tumor growth can vary considerably from indolent to locally invasive, and can even disseminate into the pleural cavity. We report a case of invasive thymoma which regressed after adminstration of steroid therapy allowing for curative thymectomy.
CASE PRESENTATION: 66 year old male with history of COPD presented with dry cough for five weeks. Chest x-ray revealed a sharply demarcated mediastinal mass (Figure 1). CT chest revealed an anterior mediastinal mass. CT guided biopsy was consistent with thymoma B1 subtype. Subsequent PET scan demonstrated locally invasive thymoma without distant metastasis. He was inoperable due to mass encroaching on the pulmonary artery (Figure 2A, 2B), and was planned for neoadjuvant chemotherapy. However, patient’s clinical course was complicated by left sided chest pain secondary to pericarditis unmitigated by NSAIDs. Patient was then started on a short course of steroids with resolution of pericarditis. When CT chest was repeated 1 month after initiation of steroids, the tumor had shrunk significantly in size (Figure 2C, 2D). Patient then underwent thymectomy, which demonstrated local lung invasion without pleural or pericardial involvement.
DISCUSSION: Although surgery is treatment of choice for thymomas, invasive and large thymomas may require chemotherapy and/or radiotherapy to decrease size and improve resectability. Use of steroid therapy has not been well established in treatment of invasive thymomas. One study demonstrated that pulse dose steroids had 47.1% (8/17) reduction in tumor size especially for Type B1 and B3 thymomas. Glucocorticoids exert anti-proliferative effects in various cell types and cause apoptosis in CD4+CD8+ thymocytes. Our patient conincidentally had regression of thymoma to glucocorticoid therapy and was able undergo surgical resection of his tumor.
CONCLUSIONS: The response of Type B1 thymomas to steroids has been noted in a few published cases. Use of flow cytometry to determine CD4+CD8+ may help identify advanced stage thymomas that may be responsive to steroids. Further studies are needed to establish the role of flow cytometry and glucocorticoids in management of invasive thymomas.
Reference #1: Kobayashi, Y. et al., Preoperative steroid pulse therapy for invasive thymoma. Cancer. May 2006. Vol 106, Issue 9 pg 1901-1907.
Reference #2: Termeer A. et al., Regression of invasive thymoma following cortiosteroid therapy. The Netherlands Journal of Medicine. 2001; 58:181-184.
Reference #3: Kirkove C. et al., Dramatic response of recurrent invasive thymoma to hig dose of corticosteroids. Clinical Oncology. 1992; 4:64-6.
DISCLOSURE: The following authors have nothing to disclose: Eshan Patel, George Juan, Ami Vaidya, Anu Thomas, Jordan Taillon, Stephen Milan, Liam Gross, Saleem Shahzad
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