Ectopic cervical thymoma accompanied by Good's syndrome.

Ectopic cervical thymoma (ECT) is a rare tumor that is frequently misdiagnosed as a thyroid tumor or other malignancy. A 34-year-old male with a right palpable neck mass had been mistakenly diagnosed with T-cell lymphoblastic lymphoma even after an open biopsy. The atypical clinical course, including hypogammaglobulinemia, led us to the correct diagnosis; ECT accompanied by Good's syndrome (GS).