Due to its classification, a dermoid cyst can occur wherever a teratoma can occur.

A dermoid cyst is a teratoma of a cystic nature that contains an array of developmentally mature, solid tissues. It frequently consists of skin, hair follicles, and sweat glands, while other commonly found components include clumps of long hair, pockets of sebum, blood, fat, bone, nails, teeth, eyes, cartilage, and thyroid tissue.

As dermoid cysts grow slowly and contain mature tissue, this type of cystic teratoma is nearly always benign. In those rare cases wherein the dermoid cyst is malignant, a squamous cell carcinoma usually develops in adults, while infants and children usually present with an endodermal sinus tumor.

Teratomas maybe found in babies, children, and adults. Teratomas of embryonal origin are most often found in babies at birth, in young children, and, since the advent of ultrasound imaging, in fetuses.

The most commonly diagnosed fetal teratomas are sacrococcygeal teratoma (Altman types I, II, and III) and cervical (neck) teratoma. Because these teratomas project from the fetal body into the surrounding amniotic fluid, they can be seen during routine prenatal ultrasound exams. Teratomas within the fetal body are less easily seen with ultrasound; for these, MRI of the pregnant uterus is more informative.

Teratomas are not dangerous for the fetus unless there is either a mass effect or a large amount of blood flow through the tumor (known as "vascular steal"). The mass effect frequently consists of obstruction of normal passage of fluids from surrounding organs. The vascular steal can place a strain on the growing heart of the fetus, even resulting in heart failure, and thus must be monitored by fetal echocardiography.

Teratomas can cause an autoimmune illness called Anti N-methyl-D-aspartate (NMDA) Receptor Encephalitis. After surgery, there is a risk of regrowth in place, or in nearby organs.

Cystic nephromas are often asymptomatic. They are typically discovered on medical imaging incidentally (i.e. an incidentaloma).

Ovarian cystadenoma is a cystic benign tumor of the ovary. Two types are recognized: serous and mucinous.

The ovarian fibroma, also fibroma, is a benign sex cord-stromal tumour.

Ovarian fibromas represent 4% of all ovarian neoplasms. They tend to occur mostly during perimenopause and postmenopause, the median age having been reported to be about 52 years, and they are rare in children. Lesions tend to be asymptomatic. If symptoms are present, the most common one is abdominal pain.

On gross pathology, they are firm and white or tan. On microscopic examination, there are intersecting bundles of spindle cells producing collagen.

There may be thecomatous areas (fibrothecoma). The presence of an ovarian fibroma can cause ovarian torsion in some cases.

A cystic nephroma, also known as multilocular cystic nephroma, mixed epithelial stromal tumour (MEST) and renal epithelial stromal tumour (REST), is a type of rare benign kidney tumour.

Some or all of the following symptoms may be present, though it is possible not to experience any symptoms:

- Abdominal pain. Dull aching pain within the abdomen or pelvis, especially during intercourse.

- Uterine bleeding. Pain during or shortly after beginning or end of menstrual period; irregular periods, or abnormal uterine bleeding or spotting.

- Fullness, heaviness, pressure, swelling, or bloating in the abdomen.

- When a cyst ruptures from the ovary, there may be sudden and sharp pain in the lower abdomen on one side.

- Change in frequency or ease of urination (such as inability to fully empty the bladder), or difficulty with bowel movements due to pressure on adjacent pelvic anatomy.

- Constitutional symptoms such as fatigue, headaches

- Nausea or vomiting

- Weight gain

Other symptoms may depend on the cause of the cysts:

- Symptoms that may occur if the cause of the cysts is polycystic ovarian syndrome (PCOS) may include increased facial hair or body hair, acne, obesity and infertility.

- If the cause is endometriosis, then periods may be heavy, and intercourse painful.

The effect of cysts not related to PCOS on fertility is unclear.

Mucinous cystadenomas may be found in the:

- Ovary - ovarian mucinous cystadenoma

- Pancreas - pancreatic mucinous cystadenoma

- Peritoneum - peritoneal mucinous cystadenoma

- Liver - mucinous cystadenoma of the liver

- Vermiform appendix - appendiceal mucinous cystadenoma (see cystadenoma)

A struma ovarii (literally: goitre of the ovary) is a rare form of monodermal teratoma that contains mostly thyroid tissue, which may cause hyperthyroidism.

Despite its name, struma ovarii is not restricted to the ovary.

The vast majority of struma ovarii are benign tumors; however, malignant tumors of this type is found in a small percentage of cases.

Mucinous cystadenoma is a benign cystic tumor lined by a mucinous epithelium. It is a type of cystic adenoma (cystadenoma).

Mucinous cystadenoma may arise in a number of locations; however, mucinous cystadenoma at different locations are not generally considered to be related to one another.

Variants with edema can be associated with Meigs' syndrome. They may be a part of nevoid basal cell carcinoma syndrome (Gorlin syndrome).

Polyembryoma is a rare, very aggressive form of germ cell tumor usually found in the ovaries. Polyembryoma has features of both yolk sac tumour and undifferentiated teratoma/embryonal carcinoma, with a characteristic finding of embryoid bodies lying in a loose mesenchymal stroma.

It has been found in association with Klinefelter syndrome.

A ruptured ovarian cyst is usually self-limiting, and only requires keeping an eye on the situation and pain medications. The main symptom is abdominal pain, which may last a few days to a several weeks, but they can also be asymptomatic. Rupture of large ovarian cysts can cause bleeding inside the abdominal cavity and in some cases shock.

Ovarian serous cystadenoma, also (less precisely) known as serous cystadenoma, is the most common ovarian neoplasm, representing 20% of ovarian neoplasms, and is benign.Human Reproduction. University of Utah Medpath http://library.med.utah.edu/kw/human_reprod/seminars/seminar4B2.html.

It has a very superficial resemblance to the most common type of ovarian cancer (serous carcinoma of the ovary) under the microscope; however, (1) it is virtually impossible to mix-up with its malignant counterpart (serous carcinoma), and (2) does not share genetic traits of indeterminate serous tumours, also called "serous borderline tumours", that may transform into serous carcinoma.

Serous cystadenomas (of the ovary) are not related to serous cystadenomas of the pancreas, i.e. the presence of an ovarian "or" pancreatic one does "not" suggest an increased risk for the other one.

Serous tumours are part of the surface epithelial-stromal tumour group of ovarian neoplasms, which derive from Mullerian epithelium.

They are common neoplasms with a strong tendency to bilaterality, and they account for 50% of all ovarian tumours.

Sixty percent are benign (cystadenoma), 10% are borderline and 30% are malignant (cystadenocarcinoma).

The soft fibroma (fibroma molle) or fibroma with a shaft (acrochordon, skin tag, fibroma pendulans) consist of many loosely connected cells and less fibroid tissue. It mostly appears at the neck, armpits or groin. The photo shows a soft fibroma of the eyelid.

SCT is seen in 1 in every 35,000 live births, and is the most common tumor presenting in newborn humans. Most SCTs are found in babies and children, but SCTs have been reported in adults and the increasingly routine use of prenatal ultrasound exams has dramatically increased the number of diagnosed SCTs presenting in fetuses. Like other teratomas, an SCT can grow very large. Unlike other teratomas, an SCT sometimes grows larger than the rest of the fetus.

Sacrococcygeal teratomas are the most common type of germ cell tumors (both benign and malignant) diagnosed in neonates, infants, and children younger than 4 years. SCTs occur more often in girls than in boys; ratios of 3:1 to 4:1 have been reported.

Historically, sacrococcygeal teratomas present in 2 clinical patterns related to the child’s age, tumor location, and likelihood of tumor malignancy. With the advent of routine prenatal ultrasound examinations, a third clinical pattern is emerging.

- Fetal tumors present during prenatal ultrasound exams, with or without maternal symptoms. SCTs found during routine exams tend to be small and partly or entirely external. The internal SCTs are not easily seen via ultrasound, unless they are large enough to reveal their presence by the abnormal position of the fetal urinary bladder and other organs, but large fetal SCTs frequently produce maternal complications which necessitate non-routine, investigative ultrasounds.

- Neonatal tumors present at birth protruding from the sacral site and are usually mature or immature teratomas.

- Among infants and young children, the tumor presents as a palpable mass in the sacropelvic region compressing the bladder or rectum. These pelvic tumors have a greater likelihood of being malignant. An early survey found that the rate of tumor malignancy was 48% for girls and 67% for boys older than 2 months at the time of sacrococcygeal tumor diagnosis, compared with a malignant tumor incidence of 7% for girls and 10% for boys younger than 2 months at the time of diagnosis. The pelvic site of the primary tumor has been reported to be an adverse prognostic factor, most likely caused by a higher rate of incomplete resection.

- In older children and adults, the tumor may be mistaken for a pilonidal sinus, or it may be found during a rectal exam or other evaluation.

The hard fibroma (fibroma durum) consists of many fibres and few cells, e.g. in skin it is called dermatofibroma (fibroma simplex or nodulus cutaneous). A special form is the keloid, which derives from hyperplastic growth of scars.

Cystic hygromas are increasingly diagnosed by prenatal ultrasonography. A common symptom is a neck growth. It may be found at birth, or discovered later in an infant after an upper respiratory tract infection. Cystic hygromas can grow very large and may affect breathing and swallowing. Some symptoms may include a mass or lump in the mouth, neck, cheek, or tongue. It feels like a large fluid-filled sac. In addition, cystic hygromas can be found in other body parts such as the arm, chest, legs, groin, and buttocks. Cystic hygromas are also often seen in Turner's syndrome, although a patient who does not have Turner's syndrome can present with this condition.

The ultrasound (US) features of struma ovarii are nonspecific, but a heterogeneous, predominantly solid mass may be seen. US demonstrates a complex appearance with multiple cystic and solid areas, findings that reflect the gross pathologic appearance of the tumor.

Magnetic resonance imaging findings may be more characteristic: The cystic spaces demonstrate both high and low signal intensity on T1- and T2-weighted images. Some of the cystic spaces may demonstrate low signal intensity on both T1- and T2-weighted images due to the thick, gelatinous colloid of the struma. No fat is evident in these lesions.

"Benign" serous tumours are unilocular (have one lobe); however if very large may be multilocular, contain clear fluid and have a smooth lining composed of columnar epithelial cells with cilia. On gross examination, the serous tumor may present as either a cystic lesion in which the papillary epithelium is contained within a few fibrous walled cysts, or the papillary projections may be away from the surface epithelium. Surgery is curative.

During prenatal ultrasound, an SCT having an external component may appear as a fluid-filled cyst or a solid mass sticking out from the fetus' body. Fetal SCTs that are entirely internal may be undetected if they are small; detection (or at least suspicion) is possible when the fetal bladder is seen in an abnormal position, due to the SCT pushing other organs out of place.

At birth, the usual presentation is a visible lump or mass under the skin at the top of the buttocks crease. If not visible, it can sometimes be felt; gently prodded, it feels somewhat like a hardboiled egg. A small SCT, if it is entirely inside the body, may not present for years, until it grows large enough to cause pain, constipation and other symptoms of a large mass inside the pelvis, or until it begins to extend out of the pelvis. Even a relatively large SCT may be missed, if it is internal, because the bony pelvis conceals and protects it. Mediastinal tumors, including teratomas, are similarly concealed and protected by the rib cage.

Some SCTs are discovered when a child begins to talk at about age 2 years and complains of their bottom hurting or feeling "poopy" when they ride in a car seat.

Other tumors can occur in the sacrococcygeal and/or presacral regions and hence must be ruled out to obtain a differential diagnosis. These include extraspinal ependymoma, ependymoblastoma, neuroblastoma and rhabdomyosarcoma.

Smaller SCTs with an external component, seen in prenatal ultrasounds or at birth, often are mistaken for spina bifida. Cystic SCT and terminal myelocystocele are especially difficult to distinguish; for more accurate diagnosis, MRI has been recommended.

Ovarian diseases can be classified as endocrine disorders or as a disorders of the reproductive system.

If the egg fails to release from the follicle in the ovary an ovarian cyst may form. Small ovarian cysts are common in healthy women. Some women have more follicles than usual (polycystic ovary syndrome), which inhibits the follicles to grow normally and this will cause cycle irregularities.

Other conditions include:

- Ovarian cancer

- Luteoma

- Hypogonadism

- Hyperthecosis