Cystic lesions


Last author update: 1 December 2012
Last staff update: 22 March 2023

Copyright: 2003-2024,, Inc.

PubMed Search: Teratoma cystic mediastinum

Hanni Gulwani, M.B.B.S.
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Cite this page: Gulwani H. Teratoma-cystic. website. Accessed April 14th, 2024.
Definition / general
  • Common; 10 - 20% of mediastinal lesions
  • In anterosuperior mediastinum
  • Neoplastic, not a developmental malformation
  • Usually contain tissue derived from at least 2 of 3 germ cell layers - endoderm, mesoderm, ectoderm
  • 50% have cough, dyspnea or chest pain
  • Tumors adhering to lung, pericardium or blood vessels are either malignant or ruptured mature teratomas with inflammatory reaction
  • Usually children or young adults (mean age 20 years)
Clinical features
  • May be associated with Klinefelter syndrome (XXY)
  • Rarely associated with acute myelogenous leukemia
Case reports
Gross description
  • Cystic with variable solid component
  • Malignant tumors are often adherent to adjacent structures or have necrosis
  • Benign tumors often have keratinous debris, cartilage or mucus
Microscopic (histologic) description
  • Mature squamous epithelium with cutaneous appendages (commonly), GI columnar epithelium, neuroglia, bone, cartilage, fat, striated muscle
  • Also choroid plexus, hepatocytes, pancreas, retinal type tissue
  • May contain immature neuroepithelial tissue (see Immature teratoma below)
  • No cholesterol granulomas
Microscopic (histologic) images

Images hosted on other servers:

Mature cystic teratoma

Mature teratoma

Immature teratoma
Definition / general
  • Contains immature neuroepithelial tissue such as embryonic tubules
  • Benign behavior in patents under age 15
Mature teratoma with malignant transformation
Definition / general
  • Very rare
  • Contain overtly malignant tissue
  • Tumors with germ cell components are classified as malignant mixed germ cell tumors

Case reports
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