Squamous cell carcinoma of the thymus with paraneoplastic hypercalcemia.

Primary thymic carcinoma is a rare neoplasm that in contradistinction to thymoma, is not supposed to be associated with a paraneoplastic syndrome. A 73-year-old man, with new onset of disorientation, was found to have an elevated serum calcium level as the cause. Computed tomography demonstrated a mediastinal mass, pericardial invasion, and metastases to the lung. Examination of a biopsy specimen revealed thymic squamous cell carcinoma. Thus, a paraneoplastic syndrome, in this case hypercalcemia, does not exclude primary carcinoma of the thymus.