Thymomas are relatively uncommon malignancies of the anterior mediastinum and present with four distinct histological types based on the specific epithelial to lymphocyte ratio: spindle cell, epithelial predominant, lymphocyte predominant, or mixed. Each histologic type of thymoma has a propensity for local invasion and metastasis and can have a wide variety of paraneoplastic manifestations, myasthenia being the most common. We present a unique case of a 34-year-old African-American female who initially presented with a history of profound weakness with repetitive motion, shortness of breath, horizontal nystagmus, persistent anemia, keratoconjunctivitis sicca, and what was initially thought to be azithromycin-induced hepatitis. Upon left anterior thoracotomy with biopsy of the mediastinal mass, pathology yielded a lymphocyte-predominant (B1), Masaoka stage IVA invasive thymoma with pericardial extension. This case illustrates the clinical significance of considering a multitude of extrathymic paraneoplastic manifestations, each with a unique physiological mechanism.
Keywords: autoimmune hepatitis; keratoconjuncivitis sicca; myasthenia; plasmapharesis; pure red cell aplasia; thymoma.