A sacral dimple (also termed pilonidal dimple or spinal dimple) is a small depression in the skin, located just above the buttocks. The name comes from the sacrum, the bone at the end of the spine, over which the dimples are found.

Sacral dimples are rare, occurring in up to 4% of the population. The majority of these dimples are minor and do not represent any underlying disease; however, the minority may be a sign of disease, notably spina bifida. Even so, this is usually the spina bifida occulta form, which is the least serious kind.

Sacral dimples are usually spotted in post-natal checks by a pediatrician, who will check:

- If the floor of the dimple be seen to be covered with skin

- If there is a tuft of hair in the dimple

- Are there any other problems in the examination of the baby, such as weak lower limbs?

- The distance from the buttocks to the dimple; lower is better.

Additionally, this can be indicative of a possible kidney problem that can be checked with an ultrasound.

Diagnosis is made primarily through physical assessment of the skin, family history of Mongolian spots, and subjective data given by the care giver. No tests are currently available for diagnosing Mongolian spots.

Management of most fetal SCTs involves watchful waiting prior to any treatment. An often used decision tree is as follows:

- Perform detailed ultrasound exam including fetal echocardiogram and Doppler flow analysis

- If fetal high output failure, placentomegaly, or hydrops

- If fetus not mature, perform pregnancy termination or fetal intervention

- Else fetus mature, perform emergency Cesarean section

- Else no emergent problems, perform serial non-stress tests and ultrasound biophysical profiles and plan delivery, as follows

- If emergent problems develop, return to top of decision tree

- Else if SCT over 5–10 cm or polyhydramnios, perform early (37 weeks gestation) elective Cesarean section

- Else SCT small and no complications, permit term spontaneous vaginal delivery

Emergent problems include maternal mirror syndrome, polyhydramnios, and preterm labor. Poor management decisions, including interventions that are either premature or delayed, can have dire consequences. A very small retrospective study of 9 babies with SCTs greater than 10 cm diameter reported slightly higher survivorship in babies remaining in utero slightly longer.

In many cases, a fetus with a small SCT (under 5 or 10 cm) may be delivered vaginally. Prior to the advent of prenatal detection and hence scheduled C-section, 90% of babies diagnosed with SCT were born full term.

SCTs are very rare in adults, and as a rule these tumors are benign and have extremely low potential for malignancy. This estimation of potential is based on the idea that because the tumor existed for decades prior to diagnosis, without becoming malignant, it has little or no potential to ever become malignant. For this reason, and because coccygectomy in adults has greater risks than in babies, some surgeons prefer not to remove the coccyx of adult survivors of SCT. There are case reports of good outcomes.

A computed tomography (CT) scan is another examination method often used for the diagnosis of Tarlov cyst. Unenhanced CT scans may show sacral erosion, asymmetric epidural fat distribution, and cystic masses that are have the same density with CSF. CT Myelogram is minimally invasive, and could be employed when MRI cannot be performed on patient.

Mongolian spots usually resolve by early childhood and hence no treatment is generally needed if they are located in the sacral area. However, sometimes it may be required for extra sacral lesions to have surgical correction. Q-switched alexandrite lasers have been used for treatment. Good results are obtained if treatment is initiated before the age of 20 years. In a study done by the University of Tokyo, the effectiveness of the Q-switched alexandrite laser in treating Mongolian spots was evaluated. A retrospective study was done from April 2003 to September 2011. 16 patients, aged 14-55, were treated with Q-switched alexandrite laser. A good therapeutic outcome was achieved on the whole group, however two patients with sacral Mongolian spots suffered from inflammatory hyperpigmentation, and two patients got post inflammatory hypopigmentation after seven sessions of laser treatment.

Two most commonly used and effective examination method for Tarlov Cysts are MRI and CT. Both CT and MRI are good imaging procedures that allow the detection of extradural spinal masses such as Tarlov cysts. Magnetic resonance neurography is an emerging imaging technology based on MRI that highlights neurologic tissue. Often cysts are under reported and under diagnosed as radiologists and neurosurgeons have been traditionally taught to ignore these cysts. Patients frequently experience difficulty in diagnosis, however this is changing as Tarlov cysts have now been recognized by NORD as a rare disease.

There are four levels (or "types") of malformation. The least severe indicates partial deformation (unilateral) of the sacrum. The second level indicates a bilateral (uniform) deformation. The most severe types involve a total absence of the sacrum.

Depending on the type of sacral agenesis, bowel or urinary bladder deficiencies may be present. A permanent colostomy may be necessary in the case of imperforate anus. Incontinence may also require some type of continence control system (e.g., self-catheterization) be utilized. Occasionally if deformities of the knees, legs or feet would prove unresponsive to corrective action, amputation at the knee may be proposed.

Before more comprehensive medical treatment was available, full amputation of the legs at the hip was often performed. More recently, the 'amputation' (actually a disarticulation because no cutting of the bone is involved) is done at the knee for those who have bent knee positions and webbing between thigh and calf to enable more ease of mobility and better seating. Some children with knee disarticulation use prosthetic legs to walk. Prosthetics for children without substantial hip and trunk control is usually abandoned in favor of faster and easier wheelchair mobility as the child's weight and age increases. Children may 'walk' on their hands and generally are able to climb and move about to accomplish whatever they need and want to accomplish. Children more mildly affected may have normal gait and no need for assistive devices for walking. Others may walk with bracing or crutches.

There is typically no cognitive impairment associated with this disability. Adults with this disability live independently, attend college, and have careers in various fields. In 2012, Spencer West, a man with sacral agenesis and both legs amputated, climbed Mt. Kilimanjaro using only his hands.

Suspicion of a chromosome abnormality is typically raised due to the presence of developmental delays or birth defects. Diagnosis of distal 18q- is usually made from a blood sample. A routine chromosome analysis, or karyotype, is usually used to make the initial diagnosis, although it may also be made by microarray analysis. Increasingly, microarray analysis is also being used to clarify breakpoints. Prenatal diagnosis is possible using amniocentesis or chorionic villus sampling.

Courses of treatment typically include the following:

- Draining the pus once awhile as it can build up a strong odor

- Antibiotics when infection occurs.

- Surgical excision is indicated with recurrent fistular infections, preferably after significant healing of the infection. In case of a persistent infection, infection drainage is performed during the excision operation. The operation is generally performed by an appropriately trained specialist surgeon e.g. an otolaryngologist or a specialist General Surgeon.

- The fistula can be excised as a cosmetic operation even though no infection appeared. The procedure is considered an elective operation in the absence of any associated complications.

A pilonidal cyst can resemble a dermoid cyst, a kind of teratoma (germ cell tumor). In particular, a pilonidal cyst in the gluteal cleft can resemble a sacrococcygeal teratoma. Correct diagnosis is important because all teratomas require complete surgical excision, if possible without any spillage, and consultation with an oncologist.

At present, treatment for distal 18q- is symptomatic, meaning the focus is on treating the signs and symptoms of the conditions as they arise. To ensure early diagnosis and treatment, people with distal 18q- are suggested to undergo routine screenings for thyroid, hearing, and vision problems.

Surgery may be necessary to address the congenital deformities frequently occurring in conjunction with arthrogryposis. Surgery on feet, knees, hips, elbows and wrists may also be useful if more range of motion is needed after therapy has achieved maximum results. In some cases, tendon transfers can improve function. Congenital deformities of the feet, hips and spine may require surgical correction at or about one year of age.

Overall prognosis for children with amyoplasia is good. Intensive therapies throughout developing years include physical therapy, occupational therapy and multiple orthopedic procedures. Most children require therapy for years, but almost 2/3 are eventually able to walk, with or without braces, and attend school.

Adult presentation in diastematomyelia is unusual. With modern imaging techniques, various types of spinal dysraphism are being diagnosed in adults with increasing frequency. The commonest location of the lesion is at first to third lumbar vertebrae. Lumbosacral adult diastematomyelia is even rarer. Bony malformations and dysplasias are generally recognized on plain x-rays. MRI scanning is often the first choice of screening and diagnosis. MRI generally give adequate analysis of the spinal cord deformities although it has some limitations in giving detailed bone anatomy. Combined myelographic and post-myelographic CT scan is the most effective diagnostic tool in demonstrating the detailed bone, intradural and extradural pathological anatomy of the affected and adjacent spinal canal levels and of the bony spur.

Prenatal ultrasound diagnosis of this anomaly is usually possible in the early to mid third-trimester. An extra posterior echogenic focus between the fetal spinal laminae is seen with splaying of the posterior elements, thus allowing for early surgical intervention and have a favorable prognosis. Prenate ultrasound could also detect whether the diastematomyelia is isolated, with the skin intact or association with any serious neural tube defects. Progressive neurological lesions may result from the "tethering cord syndrome" (fixation of the spinal cord) by the diastematomyelia phenomenon or any of the associated disorders such as myelodysplasia, dysraphia of the spinal cord.

Suspicion of a chromosome abnormality is typically raised due to the presence of developmental delays or birth defects. Diagnosis of ring 18 is usually made via a blood sample. A routine chromosome analysis, or karyotype, is usually used to make the initial diagnosis, although it may also be made by microarray analysis. Increasingly, microarray analysis is also being used to clarify breakpoints. Prenatal diagnosis is possible via amniocentesis or chorionic villus sampling.

Some tests which detect cancer could be called "screening for epithelial dysplasia". The principle behind these tests is that physicians expect dysplasia to occur at the same rate in a typical individual as it would in many other people. Because of this, researchers design screening recommendations which assume that if a physician can find no dysplasia at certain time, then doing testing before waiting until new dysplasia could potentially develop would be a waste of medical resources for the patient and the healthcare provider because the chances of detecting anything is extremely low.

Some examples of this in practice are that if a patient whose endoscopy did not detect dysplasia on biopsy during screening for Barrett's esophagus, then research shows that there is little chance of any test detecting dysplasia for that patient within three years.

Individuals at average-risk for colorectal cancer should have another screening after ten years if they get a normal result and after five years if they have only one or two adenomatous polyps removed.

Surgery

Surgical intervention is warranted in patients who present with new onset neurological signs and symptoms or have a history of progressive neurological manifestations which can be related to this abnormality. The surgical procedure required for the effective treatment of diastematomyelia includes decompression (surgery) of neural elements and removal of bony spur. This may be accomplished with or without resection and repair of the duplicated dural sacs. Resection and repair of the duplicated dural sacs is preferred since the dural abnormality may partly contribute to the "tethering" process responsible for the symptoms of this condition.

Post-myelographic CT scanning provides individualized detailed maps that enable surgical treatment of cervical diastematomyelia, first performed in 1983.

Observation

Asymptomatic patients do not require surgical treatment. These patients should have regular neurological examinations since it is known that the condition can deteriorate. If any progression is identified, then a resection should be performed.

The disorder is an autosomal dominant genetic trait caused by a mutation in the HLXB9 homeobox gene. In 2000 the first large series of Currarino cases was genetically screened for HLXB9 mutations, and it was shown that the gene is specifically causative for the syndrome, but not for other forms of sacral agenesis. The study was published on the American Journal of Human Genetics.

Benign fibrous histiocytomas (also known as dermal dendrocytoma, dermatofibroma, fibrous dermatofibroma, fibrous histiocytoma, fibroma simplex, nodular subepidermal fibrosis, and sclerosing hemangioma) are benign skin growths.

Open spina bifida can usually be detected during pregnancy by fetal ultrasound. Increased levels of maternal serum alpha-fetoprotein (MSAFP) should be followed up by two tests – an ultrasound of the fetal spine and amniocentesis of the mother's amniotic fluid (to test for alpha-fetoprotein and acetylcholinesterase). AFP tests are now mandated by some state laws (including California). and failure to provide them can have legal ramifications. In one case, a man born with spina bifida was awarded a $2-million settlement after court found his mother's OBGYN negligent for not performing these tests. Spina bifida may be associated with other malformations as in dysmorphic syndromes, often resulting in spontaneous miscarriage. In the majority of cases, though, spina bifida is an isolated malformation.

Genetic counseling and further genetic testing, such as amniocentesis, may be offered during the pregnancy, as some neural tube defects are associated with genetic disorders such as trisomy 18. Ultrasound screening for spina bifida is partly responsible for the decline in new cases, because many pregnancies are terminated out of fear that a newborn might have a poor future quality of life. With modern medical care, the quality of life of patients has greatly improved.

The prognosis for vaginal atresia is one that is complicated. There are variations in patients' anatomic findings as well as an absence in consistent surgical techniques which makes it difficult to give a prognosis for this condition. Along with other conditions that give rise to an abnormal perineum (i.e. ambiguous genitalia and other various abnormalities that range from cloaca to urogenital sinus), individuals with vaginal atresia often report reconstruction as an outcome of treatment. Due to this, it is difficult to compare outcomes between individuals with vaginal atresia.

The diagnosis depends on appropriate patient history backed by imaging studies like X ray and MRI. Lumbosacral spine radiographs help in the identification of the skeletal abnormality. MRI helps in confirmation.

The Currarino syndrome (also Currarino triad) is an inherited congenital disorder where either the sacrum (the fused vertebrae forming the back of the pelvis) is not formed properly, or there is a mass in the presacral space in front of the sacrum, and (3) there are malformations of the anus or rectum. It can also cause an anterior meningocele or a presacral teratoma.

Presacral teratoma usually is considered to be a variant of sacrococcygeal teratoma. However, the presacral teratoma that is characteristic of the Currarino syndrome may be a distinct kind.

Fertility options for girls and women with Rokitansky-Mayer-Küster-Hauser syndrome has a bit more information. Girls and women who are born without a complete vagina, but still have a regular sized uterus more than likely will be able to become pregnant and have a baby. However, if the female is born with a tiny uterus, or without a uterus, they will not be able to have a baby. As the ovaries may be normal in this case, the egg may be fertilized with a donor's or partner's sperm. In this case, surrogacy, would be an option where there will be a gestational carrier to carry the pregnancy for the couple. Adoption may also be an option for females with Rokitansky-Mayer-Küster-Hauser syndrome. Another possibility could be uterine transplants, however this a new and developing form of treatment. Fertility options are being researched daily, so there can always be a new method available.

Any pain associated with Rokitansky-Mayer-Küster-Hauser syndrome comes from menstruation related cramping and can be treated with several ways. Individuals with this syndrome may be born with a uterine remnant (tiny uterus), which can fill with become filled with blood in the pelvic cavity causing pain. A medical professional can assess the severity of having a uterine remnant within each patient to determine if removal of the uterus is necessary.