ovary chapter aca

Overview of Tumors

• Certain benign tumors, like teratomas, are often self-limiting if composed entirely of mature tissues.

• There are different types of teratomas that primarily occur in the ovaries, with mature solid and cystic teratomas being the most common types.

Mature Solid Teratoma

• Predominantly solid in gross appearance, with small cystic areas present.

• Composed entirely of adult tissues from all three germ layers.

• Requires extensive sampling to differentiate from grade 1 immature teratoma; some refer to it as "grade 0" immature teratoma.

• Primarily occurs in young women (second decade of life) and has an excellent prognosis, including cases with peritoneal implants.

Mature Cystic Teratoma

• Accounts for about 20% of all ovarian neoplasms and is most common in childhood (88% unilateral).

• Often manifests symptoms related to mass effects but can lead to complications such as hemolytic anemia, virilization, or paraneoplastic encephalitis, commonly linked to NMDA receptor antibodies.

• Grossly multiloculated with cystic content primarily containing keratin, sebum, and hair; may have structures like teeth and even rudimentary human features (fetiform teratomas).

• Histologically, it includes variations in tissue types such as epidermis, glial tissue, respiratory tissue, gastrointestinal tract tissue, and thyroid tissue in 10% of cases.

Grading of Immature Teratomas

• Grade I: Rare foci of immature neuroepithelial tissue.

• Grade II: Occasional immature neuroepithelial foci with mitoses.

• Grade III: Few mature tissues, extensive neuroepithelial elements present.

• Distinguishing features are necessary to differentiate from teratomas with yolk sac or embryonal carcinoma patterns.

Complications and Changes Related to Teratoma

• Peritoneal nodules composed of mature glial and neuronal tissue indicate a benign condition known as gliomatosis peritonei.

• Rupture of mature teratomas can lead to foreign body reactions mimicking metastatic cancers.

Somatic-type Tumors in Mature Cystic Teratomas

• Rare, occurring in approximately 2% of cases; can exhibit malignant changes like squamous cell carcinoma.

• Other possible tumors include carcinoid tumors, adenocarcinoma, and various sarcomas.

• Malignant transformations may result in significant chromosomal aberrations.

Epidermoid Cyst and Struma Ovarii

• Epidermoid cysts represent a different entity from mature cystic teratomas; may arise from epithelial cell nests but lack skin adnexal components.

• Struma ovarii refers to the predominance of thyroid tissue in a teratoma, which may lead to conditions like hyperthyroidism and is distinguishable by immunohistochemical studies.

Carcinoid Tumors

• Can occur as metastases or primary tumors in the ovary.

• Primary ovarian carcinoids can exhibit aggressive behavior and may develop carcinoid syndrome independent of metastases.

• Mucinous types are aggressive and may carry a poor prognosis.

Sex Cord–Stromal Tumors

• Make up about 5% of ovarian neoplasms, differentiating in the direction of sex cords and specialized stroma.

• Granulosa cell tumors are the most significant subtype, with hormonal implications, variable growth patterns, and specific immunohistochemical markers like inhibin and FOXL2.

• Adult type is often linked with hyperestrinism, while juvenile type can occur in younger patients.

Immunohistochemical Markers

• Inhibin, FOXL2, SF-1: These markers help identify sex cord-stromal tumors.

• Variability in staining may complicate diagnosis, and the absence of immunohistochemical staining does not exclude tumoral presence.

Key Considerations

• Thorough sampling and accurate diagnosis are essential due to overlapping characteristics between different tumor types.