Cervical thymic cysts and parathyroid cysts.

Cysts which originated from embryonal remnants are often observed in the cervical region. Among these cysts, branchiogenic cleft cysts and thyroglossal cysts are most commonly encountered. Parathyroid cysts and cervical thymic cysts are known to be a rare entity. Reviewing the world literature of the latter two, only a few reports were noted. There is, in addition, some confusion in terminology about cysts and cystic formations. We are convinced that parathy roid cysts and cervical thymic cysts should not be included with cystic formations secondary to adenoma or hyperplasia of the gland. Based upon this assumption the following discussions will be made. Since 1961 four parathyroid cysts and one cervical thymic cyst were found in the past 8 years in our clinic. Clinical and histopathological analyses were made on these two types of cysts. There are many resemblances and we would like to conclude that both of these cysts were originally developed from embryonal remnant.