Teratoma.Teratomas are neoplasms made up of tissues foreign to the site of occurrence. They contain tissue from all three embryonic germ layers (endoderm endoderm (ĕn`dədûrm'), in biology, inner layer of tissue formed in the gastrula stage of the developing embryo. At the end of the blastula stage, cells of the embryo are arranged in the form of a hollow ball. , mesoderm mesoderm, in biology, middle layer of tissue formed in the gastrula stage of the developing embryo. At the end of the blastula stage, cells of the embryo are arranged in the form of a hollow ball. , and ectoderm ectoderm, layer of cells that covers the surface of an animal embryo after the process of gastrulation has occurred. This outer layer, together with the endoderm, or inner layer, is present in all early embryos. ). Other terms--choristoma, hamartoma, heterotopia, epignathus, and dermoid--refer to separate, unique entities that are not covered here. Only about 6% of all teratomas occur in the head and neck. Patients range in age from newborns to those in their 9th decade, although most patients are neonates and infants. Many of these patients are born prematurely, and their births are often complicated by polyhydramnios. Teratomas are distributed equally between the sexes. Interestingly, neonates have benign tumors, while malignant tumors are seen only in adults. The anatomic site of involvement varies (e.g., neck, sinonasal tract, or nasopharynx nasopharynx /na·so·phar·ynx/ (-far´inks) the part of the pharynx above the soft palate.nasopharyn´geal na·so·phar·ynx n. ). Most patients present with a midline mid·line n. A medial line, especially the medial line or plane of the body. midline, n the line equidistant from bilateral features of the head. mass lesion and a facial deformity, which are often accompanied by other associated symptoms (e.g., respiratory distress, dyspnea, stridor Stridor Definition Stridor is a term used to describe noisy breathing in general, and to refer specifically to a high-pitched crowing sound associated with croup, respiratory infection, and airway obstruction. , or difficulty swallowing). Other congenital anomalies may be present, especially in neonatal patients. Macroscopically, these tumors are well-circumscribed, lobulated lobulated /lob·u·lat·ed/ (lob´ul-at-id) made up of lobules. lobulated made up of lobules. , soft, and cystic. Islands of gritty material consistent with bone and cartilage are often identified. These tumors contain a wide array of mature and immature tissues interspersed with one another. Squamous epithelium, respiratory epithelium, glandular epithelium, gastrointestinal epithelium, thyroid gland, pancreas, liver, neural tissue, pigmented retinal anlage anlage /an·lage/ (ahn-lah´ge) (an´laj) pl. anla´gen [Ger.] primordium. an·la·ge or An·la·ge n. pl. an·la·ges or an·la·gen 1. , immature neuroblastomal elements, cartilage, bone, muscle, fat, and loose myxoid-to-fibrous embryonic mesenchymal connective tissue are identified (figures 1 and 2). If the entire tumor is made up of predominantly immature elements, a malignant teratoma or teratocarcinosarcoma must be excluded. [FIGURES 1-2 OMITTED] Complete surgical excision is curative, although complications and death may occur secondary to the space-occupying and destructive character of these benign neoplasms. Suggested reading Batsakis JG, el-Naggar AK, Luna MA. Teratomas of the head and neck with emphasis on malignancy. Ann Otol Rhinol Laryngol 1995;104:496-500. Thompson LD, Rosai J, Heffess CS. Primary thyroid teratomas: A clinicopathologic study of 30 cases. Cancer 2000;88:1149-58. From the Department of Pathology, Woodland Hills Medical Center, Southern California Permanente Medical Group, Woodland Hills, Calif. |
|
||||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion