Dermoid Cyst

Question 1

Types of ovarian germ cell tumors

Answer 1

Teratomas
Dysgerminoma (immature germ cells)
Endodermal sinus (yolk sac) tumors
Mixed germ cell tumors
Embryonal/choriocarcinomas

Question 2

Epidemiology of teratomas

Answer 2

Most common type of germ cell neoplasm

95% are dermoid cyst
Most common ovarian tumor in women in second and third decade of life

10-17% bilateral

Question 3

What are the 4 categories of teratomas?

Answer 3

Mature (cystic or solid, benign)
Immature (malignant)
Malignant due to component of another somatic malignant neoplasm
Monodermal/highly specialized

Question 4

Pathophysiology of dermoid cyst

Answer 4

Failure of meiosis II or from premeiotic cell in which meiosis I has failed

Question 5

Histology

Answer 5

Mature tissue of ectodermal (skin, hair, sebaceous glands), mesodermal (muscle), endodermal (lung, GI)

Macroscopic - multicystic mass with hair, teeth, skin mixed into sebaceous, thick, sticky, often foul-smelling material

Question 6

Clinical manifestations of dermoid cyst

Answer 6

Most asymptomatic
Torsion
Rupture of dermoid cyst (uncommon) followed by shock and hemorrhage (chemical peritonitis)\
NMDA receptor encephalitis

Question 7

Diagnosis

Answer 7

Ultrasound specificity is 98-100%
Accurate noninvasive diagnosis

Definitive diagnosis made at time of surgical excision

Question 8

Treatment - why

Answer 8

Ovarian cystectomy
- preserve ovarian tissue
avoid potential problems such as torsion, rupture, malignant components developing

Completed childbearing - salpingo-oophorectomy

Question 9

Malignant transformation of dermoid cyst

Answer 9

0.2-2%

squamous cell carcinoma from ectoderm is the most common secondary neoplasm

Question 10

Risk factors for malignant neoplasm in mature cystic teratoma

Answer 10

> age 45 (mean age 50)
10 cm tumor, rapid growth
flow on doppler

Question 11

Monodermal highly specialized teratomas

Answer 11

rare subset

struma ovarii and carcinoid

Question 12

Struma ovarii

Answer 12

Mature thyroid tissue
Secretes thyroid hormone in 25-35% of patients

Most are benign and by excision
Malignant transformation is exceedingly rare

Question 13

Carcinoid neoplasm

Answer 13

Bland cells with endocrine features and fine vascular network
Secrete bioactive polypeptides/amines - flushing and diarrhea

Carcinoid syndrome in 1/3 of cases, can develop without hepatic metastases due to direct venous drainage from ovary into systemic circulation

Question 14

Mature solid teratoma

Answer 14

Unilateral and benign

may be difficult to differentiate from malignant solid immature teratomas

Question 15

Immature teratoma - epidemiology

Answer 15

<1% of ovarian teratoma
most common in first 2 decades of life
36% of all malignant OGCNs

Question 16

Histology of immature teratoma

Answer 16

3 germ cell layers with varying amounts of immature tissue, most frequently with neural differentiation

Question 17

Grading of immature teratoma

Answer 17

Only OGCN that is histologically graded

Differentiation based on immature neural elements - important indicator of risk for extraovarian spread.

Question 18

Management of immature teratoma

Answer 18

Unilateral SBO alone is adequate for stage IA grade 1

Controversial about adjuvant chemotherapy for grade 2 or 3

Question 19

Staging of ovarian tumors

Answer 19

T1 (to ovaries) A (1), B (both), C (washing)
T2 pelvic extension
T3 peritoneal metastasis outside of pelvis