A rare and particular form of goiter to recognize.

Dyshormonogenetic goiter is a rare cause of congenital hypothyroidism occurring due to a lack of enzymes necessary for the synthesis of thyroid hormones. It is morphologically characterized by architectural and cellular pleomorphism that may mimic thyroid malignancy and cause difficulties in differential diagnosis. We report a new case occurring in a 37-year-old male with history of hypothyroidism since the age of 
6 years treated by L-thyroxin. He developed a progressively slow growing multinodular goiter and consulted for recent dyspnea. Computed tomography scan showed a multinodular plunging goiter with compression of the trachea and vessels in the left side. A total thyroidectomy was performed. Gross examination revealed an enlarged and multinodular thyroid gland, presenting hemorrhagic changes in the larger nodules. Histologically, the features were consistent with dyshormonogenetic goiter. The literature on the histopathology of dyshormonogenetic goiter is reviewed and clues to avoid inappropriate overdiagnosis of malignancy are given.