MALIGNANT THYMOMA IN AN ECTOPIC CERVICAL THYMUS: A DIAGNOSTIC DILEMMA TO THE CLINICIAN

Thymoma is a term that should be restricted to neoplasms of thymic epithelial cells independently of the presence or number of lymphocytes. Ectopic Thymoma (ET) is a rare tumor thought to originate from ectopic rests of thymic tissue caused by defective migration of the embryonic thymus. ET has been reported in a variety of sites such as the neck (Ectopic cervical thymoma, ECT), chest wall, pleura, lung, and heart. Among these ectopic sites, the cervical region appears to be one of the most frequent locations, where close proximity to the thyroid frequently results in a mistaken clinical impression of a primary thyroid neoplasm. ECT most commonly presents as an enlarging neck mass, although one case of ECT with myasthenia gravis as the presenting symptom is on record. In this paper, we report the clinic-pathological features & management of one case of ECT seen in our institution. Thymoma is a rare neoplasm with a largely indolent growth pattern. Because of its potential for invasion and local recurrence, however, a multidisciplinary approach is recommended for the evaluation and treatment of these patients. Although responsive to both chemotherapy and radiation, the mainstay of treatment is surgical resection. Inoperable patients warrant a strategy of induction chemotherapy followed by a surgical reassessment post-therapy, and adjuvant radiation therapy is generally recommended, despite lacking prospective studies, for any evidence of invasive disease regardless of the degree of resection obtained. Durable responses can be obtained both in the metastatic and recurrent setting, and novel therapies are currently being explored.