Ovary

Germ cell tumors

Teratoma-mature



Topic Completed: 10 August 2021

Minor changes: 10 August 2021

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PubMed Search: Mature teratoma [TI] ovary [TIAB]


Shannon Mingo Welter, M.D.
Mahmoud A. Khalifa, M.D., Ph.D.
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Cite this page: Welter SM, Khalifa MA. Teratoma-mature. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/ovarytumorteratomamature.html. Accessed October 21st, 2021.
Definition / general
  • Benign tumor of the ovary composed of mature tissue representing at least 2 embryonic layers (ectoderm, mesoderm or endoderm)
Essential features
  • Mature tissue representing at least 2 embryonic layers
  • If malignant transformation, prognosis is related to the type of malignancy
Terminology
  • Mature cystic teratoma
  • Not recommended: dermoid cyst, mature solid teratoma
ICD coding
  • ICD-O: 9080/0 - teratoma, benign
  • ICD-11: 2F32.0 - cystic teratoma
Epidemiology
  • Most common ovarian tumor (20% of all ovarian tumors, 95% of all ovarian germ cell tumors)
  • Reproductive age
  • 10% bilateral (Cancer 1971;27:343)
Sites
  • Ovary
Pathophysiology
Etiology
  • No known causative agents
Diagrams / tables

Images hosted on other servers:
Signs of ovarian teratomas in different imaging modalities

Signs of ovarian teratomas in different imaging modalities

Clinical features
Diagnosis
  • Mainly by ultrasound
  • Histologic examination
Radiology description
  • Wide variety of presentations, depending on the tissues present (see Diagrams / tables)
Radiology images

Images hosted on other servers:
Ultrasound characteristics Ultrasound characteristics

Ultrasound characteristics

CT characteristics CT characteristics

CT characteristics

MRI characteristics

MRI characteristics

Prognostic factors
  • Benign tumor
  • Malignant transformation occurs rarely
    • Usually in older patients
    • Most common is squamous cell carcinoma
    • Prognosis dependent on stage
  • Microscopic foci of immature neuroepithelium does not warrant diagnosis of immature teratoma and will not affect prognosis (Int J Gynecol Pathol 1987;6:203)
  • Gliomatosis peritonei (mature glial tissue implanted on peritoneal surface) does not adversely affect prognosis (J Ovarian Res 2016;9:45)
  • Anti–n-methyl-D-aspartate receptor (NMDAR) encephalitis will have best outcome with early treatment (immunotherapy and tumor removal) (Lancet Neurol 2013;12:157)
Case reports
Treatment
  • Cystectomy in young women to preserve fertility
  • Salpingo-oophorectomy in older women
Gross description
Gross images

Contributed by Shannon Mingo Welter, M.D.
Fragmented ovarian mature teratoma

Fragmented ovarian mature teratoma

Ovarian mature teratoma

Ovarian mature teratoma


AFIP images
Mature teratoma Mature teratoma

Mature teratoma

Frozen section description
  • Rarely performed but will show mixture of mature tissues
  • Solid areas should be sampled to exclude immature teratoma
Microscopic (histologic) description
  • Mixture of mature, benign tissues
    • Ectodermal (most common): squamous epithelium, sebaceous glands, hair follicles, brain tissue
    • Mesodermal (second most common): bone, cartilage, smooth muscle, fibroadipose tissue
    • Endodermal: intestinal or respiratory epithelium, thyroid, salivary gland
  • Microscopic foci of immature neuroepithelium (less than or equal to 4 foci or 21 mm2) does not warrant diagnosis of immature teratoma and will not affect prognosis (Int J Gynecol Pathol 1987;6:203)
  • Fat necrosis and foreign body reaction may be seen
  • Cases associated with NMDAR encephalitis usually show neuroglial tissue associated with lymphoid aggregates with germinal centers, low number of mature neurons and a hypercellular astrocyte population (Am J Surg Pathol 2019;43:949)
  • Reference: StatPearls: Cystic Teratoma [Accessed 29 July 2021]
Microscopic (histologic) images

Contributed by Shannon Mingo Welter, M.D.
Skin with sebaceous glands

Skin with sebaceous glands

Skin with keratin and adnexa

Skin with keratin and adnexa

Rokitansky nodule

Rokitansky nodule

Mucin producing epithelium

Mucin producing epithelium

Multiple tissue types

Multiple tissue types


Orderly arrangement of tissues

Orderly arrangement of tissues

Cartilage and other mature tissues

Cartilage and other mature tissues

Glial tissue

Glial tissue

Gliomatosis peritonei

Gliomatosis peritonei

Virtual slides

Images hosted on other servers:
Mature teratoma with well differentiated neuroendocrine tumor

Mature teratoma with
well differentiated
neuroendocrine tumor

Molecular / cytogenetics description
  • Diploid with normal (46XX) karyotype
Sample pathology report
  • Ovary, right, cystectomy:
    • Mature teratoma
Differential diagnosis
  • Immature teratoma:
  • Monodermal teratoma:
    • Contain a single germ layer
      • Neuroectodermal cyst - lined by ependymal cells
      • Epidermoid cyst - lined by squamous epithelium (no sebaceous glands present)
    • Struma ovarii - thyroid tissue is the dominant or sole component
    • Strumal carcinoid - well differentiated neuroendocrine tumor admixed / juxtaposed with thyroid tissue
Board review style question #1

A 25 year old pregnant woman is seen in the obstetrics clinic for a routine ultrasound. During the exam, a cystic mass is noted near her left ovary. The mass is eventually surgically removed and a pathologic examination shows the features in the picture shown above. What is an essential feature of this tumor?

  1. Gliomatosis peritonei
  2. Immature tissue
  3. Mature tissue representing at least 2 embryonic layers
  4. Size greater than 10 cm
Board review style answer #1
C. Mature tissue representing at least 2 embryonic layers. Mature teratoma can contain microscopic foci of immature neuroectodermal tissue in the cyst wall. This finding does not change the prognosis and should not lead to the tumor being classified as immature teratoma. Gliomatosis peritonei is a rare finding associated with teratoma and size of tumor is variable with most less than 10 cm. Mature teratomas must contain at least 2 embryonic layers.

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Reference: Teratoma - mature
Board review style question #2

A 19 year old woman presents with a symptom of left adnexal fullness. On physical examination, a 9 cm mass is palpated near the left ovary. The mass is surgically removed and a gross picture is shown above. What is the most likely diagnosis?

  1. Yolk sac tumor
  2. Immature teratoma
  3. Lipoma
  4. Mature teratoma
Board review style answer #2
D. Mature teratoma. The photo shows a mass with yellow sebaceous material and hair. In a 19 year old woman, this most likely represents a mature teratoma. Mature teratomas are the most common ovarian tumor and are especially common in women of reproductive age.

Comment Here

Reference: Teratoma - mature
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