Snapshot A 38-year-old female presents with fatigable chewing and "seeing double" when reading a book. She has also noted a "head drop" when she was bathing her dog. On physical exam, pupils are equal, round, and reactive. Ptosis is elicited with prolonged staring towards the ceiling. A glove of ice is applied to the eyelids, and ptosis is improved. She is seropositive for antibodies against acetylcholine receptors. A chest CT is performed, showing an anterior mediastinal mass. (Myasthenia gravis) Introduction Arises in the anterior mediastinum thymus is involved in T-cell maturation active during infancy and childhood visible on chest radiograph i.e., thymic "sail sign" at superior, right border of the heart at puberty, will be replaced by fatty tissue Epidemiology Most patients with thymoma are between 40-60 years of age No sexual predilection Thymoma are associated with paraneoplastic syndromes (e.g., myasthenia gravis, immunodeficiency, pure red cell aplasia, good syndrome) Presentation Symptoms thyomoma dependent on size horseness recurrent larygneal nerve involvement dysphagia chest pain cough superior vena cava syndrome thymic carcinoma similar to thymoma, but more aggressive (e.g., medistainal structure invasion) extrathoracic metastasis e.g., kidneys, extrathoracic lymphnodes, brain IMAGING Thoracic CT or MRI STUDIES Histological evaluation thymic neoplasm classification Differential Retrosternal thyroid Mediastinal germ cell tumor check an hCG and AFP Lymphoma Treatment Surgical first-line in most cases when complete resection is feasible allows histological evaluation of specimen Neoadjuvant chemotherapy or chemoradiation in those who are not surgical candidates may be used prior to surgery may improve likelihood of complete resection Radiation therapy and/or chemotherapy in non-operative candidates may prolong survival Prognosis Dependent on stage and resectability