OT are usually detected in young women; the patients' median age at diagnosis is 35 and 27 years in the case of mature cystic teratoma and immature teratoma, respectively  .
Abdominal pain is the single most important symptom of OT. Women may also experience abnormal uterine bleedings. Occasionally, OT exerts local mass effects that interfere with bladder and intestinal function. Torsion, rupture, and infection of OT are rare events, but dreaded complications causing a rapid deterioration of a patient's general condition . Of note, about one in six patients are asymptomatic. Here, OT is incidental finding diagnosed during a routine physical and gynecological examination.
Entire Body System
- Behavior Problem
Postoperatively, the patient's menstrual cycles became regular and her behavioral problems resolved. Her testosterone levels fell precipitously as well. [ncbi.nlm.nih.gov]
- Generalized Seizure
A 21-year-old woman developed psychiatric symptoms, progressive unresponsiveness, generalized seizures, severe dyskinesia, marked fluctuation of blood pressure, and hypersalivation after a flu-like episode. [ncbi.nlm.nih.gov]
Workup comprises diagnostic imaging to confirm the presence of an ovarian mass and to assess whether metastases have developed in other parts of the reproductive system, lymph nodes, or distant organs:
- Ultrasonography yields reliable results regarding the presence of ovarian tumors and allows for the detection of metastases in other organs and lymph nodes. The ultrasonographic image of OT typically comprises hypo- and hyperechogenic areas, which correspond to heterogeneous tissues, calcified and fluid-filled spaces, and septa. This technique is readily available, cost-effective, and highly specific .
- Availability and costs argue against the employment of computed tomography and magnetic resonance imaging. They are, however, of major importance for tumor staging in the case of malignant OT. Additionally, these techniques may be helpful to clarify uncertain diagnoses , owing to a higher sensitivity (60-94% for ultrasonography, 93-98% for computed tomography, ).
In order to distinguish between benign and malignant OT, measurements of serum α-1-fetoprotein, β-human chorionic gonadotropin and cancer antigen 125 (CA 125) should be performed. Enhanced concentrations of either marker are indicative of malignancy  .
Here, we report our experience with two pediatric patients, in whom no tumors were present during treatment for encephalitis, but in whom ovarian teratomas developed without encephalitis relapse after treatment was completed. [ncbi.nlm.nih.gov]
Prognosis in advanced disease condition such as the case presented is generally poor although radical pelvic surgery with resection of the adjacent involved bladder before radiotherapy would probably have improved her prognosis. [ncbi.nlm.nih.gov]
The etiological investigation is then crucial to early identification of the tumor in order to optimize the prognosis and to limit neurological sequelae. [ncbi.nlm.nih.gov]
The etiology of pneumatosis cystoides-like structures in ovarian teratomas is not clear. The first case of ovarian mature cystic teratoma with pneumatosis cystoides-like struc- tures was published in 1989 by Maudsley and Zakhour(9). [newslab.sk]
The epidemiology of ovarian cancer. Gynecol Oncol. 1991 Oct; 43 (1):9–23. [ PubMed ] Ross RK, McCurtis JW, Henderson BE, Menck HR, Mack TM, Martin SP. Descriptive epidemiology of testicular and prostatic cancer in Los Angeles. [ncbi.nlm.nih.gov]
References:    Epidemiological data refers to the US, unless otherwise specified. [amboss.com]
Epidemiology Benign ovarian tumours occur in 30% of females with regular menses (eg, luteal cysts as incidental findings on pelvic scans) and 50% of females with irregular menses. [patient.info]
They used sophisticated cytogenetic techniques to demonstrate that these tumors are of germ cell origin and arise from a single germ cell after the first meiotic division.  Epidemiology Frequency Sacrococcygeal teratomas (SCT) are the most common tumors [emedicine.medscape.com]
Josep Dalmau and colleagues in the Department of Neurology at the University of Pennsylvania published a series of papers documenting a link between encephalitis and ovarian teratomas. 1-5 The pathophysiologic connection is thought to be the presence [obgmanagement.com]
In case of ovarian teratoma, the hypothesis of an autoimmune pathophysiology [ 9 ] is supported by its composition of ectoderm; mesoderm and endoderm which could induce an autoimmune response [ 5, 8 ]. [panafrican-med-journal.com]
Pathophysiology: Teratomas are made up of a variety of parenchymal cell types representative of more than a single germ layer, usually all 3. Arising from totipotential cells, these tumors typically are midline or para-axial. [csh.org.tw]
Teratomas, specifically solid teratomas, are essentially devoid of organization; thus, the presence of some degree of organization, a high degree of cellular differentiation, and cystic structure differentiates dermoids from teratomas.  Pathophysiology [emedicine.medscape.com]
No analysis of relapse risk has yet been reported in cases of tumor development after treatment, and at this point, whether or not resection is needed to prevent relapse remains unclear. [ncbi.nlm.nih.gov]
Brain herniation prevented CSF analysis in the infant. [n.neurology.org]
With the decrease in swelling, doctors hope that permanent brain damage may be prevented. Testing. Meredith noticed that Janell had a hemolytic anemia. [abc.go.com]
- Mature cystic teratoma is the most common type of OT. Tumor cells are well differentiated and derive from at least two of the three germ cell layers. A mature cystic teratoma typically consists of an outer layer of squamous epithelium enclosing fat, muscle, hair follicles, skin glands and liquid, sebaceous material. Therefore, this benign neoplasm is also referred to as a dermoid cyst. A considerable share of patients presents with bilateral tumors  . Of note, mature cystic teratomas have occasionally been reported to undergo malignant transformation .
- Immature teratomas are similarly composed of tumor cells deriving from at least two germ cell layers. However, these cells are poorly differentiated and this type of OT is generally associated with higher tumor grades. Fortunately, less than 1% of OT are immature teratomas.
- Monodermal teratoma differs from the afore-described variants in that it contains degenerated cells of either ectodermal, mesodermal or endodermal origin only. Struma ovarii and ovarian carcinoid tumor fall into this category and primarily contain thyroid and neuroectodermal tissue, respectively. Other types of monodermal teratoma have been described.
- Jung SE, Lee JM, Rha SE, Byun JY, Jung JI, Hahn ST. CT and MR imaging of ovarian tumors with emphasis on differential diagnosis. Radiographics. 2002;22(6):1305-1325.
- Outwater EK, Siegelman ES, Hunt JL. Ovarian teratomas: tumor types and imaging characteristics. Radiographics. 2001;21(2):475-490.
- Wu RT, Torng PL, Chang DY, et al. Mature cystic teratoma of the ovary: a clinicopathologic study of 283 cases. Zhonghua Yi Xue Za Zhi (Taipei). 1996;58(4):269-274.
- Sah SP, Uprety D, Rani S. Germ cell tumors of the ovary: a clinicopathologic study of 121 cases from Nepal. J Obstet Gynaecol Res. 2004;30(4):303-308.
- Rojas CP, Ganjei-Azar P, Garcia-Buitrago MT. Unexpected Malignant Diagnosis in Colonic Biopsies: Malignant Transformation of Ovarian Mature Teratomas-Two Case Reports and Review of the Literature. Case Rep Pathol. 2015;2015:905462.
- Jorge S, Jones NL, Chen L, et al. Characteristics, treatment and outcomes of women with immature ovarian teratoma, 1998-2012. Gynecol Oncol. 2016;142(2):261-266.
- Park SB, Kim JK, Kim KR, Cho KS. Imaging findings of complications and unusual manifestations of ovarian teratomas. Radiographics. 2008;28(4):969-983.
- Saba L, Guerriero S, Sulcis R, Virgilio B, Melis G, Mallarini G. Mature and immature ovarian teratomas: CT, US and MR imaging characteristics. Eur J Radiol. 2009;72(3):454-463.
- Wasnik AP, Menias CO, Platt JF, Lalchandani UR, Bedi DG, Elsayes KM. Multimodality imaging of ovarian cystic lesions: Review with an imaging based algorithmic approach. World J Radiol. 2013;5(3):113-125.
- Panteli C, Curry J, Kiely E, et al. Ovarian germ cell tumours: a 17-year study in a single unit. Eur J Pediatr Surg. 2009;19(2):96-100.
- Taskinen S, Fagerholm R, Lohi J, Taskinen M. Pediatric ovarian neoplastic tumors: incidence, age at presentation, tumor markers and outcome. Acta Obstet Gynecol Scand. 2015;94(4):425-429.