13q deletion syndrome can only be definitively diagnosed by genetic analysis, which can be done prenatally or after birth. Increased nuchal translucency in a first-trimester ultrasound may indicate the presence of 13q deletion.

Cardiac myxomas can be difficult to manage surgically because of recurrence within the heart, often far away from the site of the initial tumor.

The American neurosurgeon Harvey Cushing in 1914 reported a patient with a pituitary tumour that he had operated on. Post mortum finding were suggestive of Carney complex. this condition had yet to be described. In 2017 archived tissue from this operation were subjected to DNA sequencing. This revealed a Arg74His (Arginine to Histidine: Guanine (G)-> Adenosine (A) transition in the second codon position of the 74 codon in the protein) mutation in the PRKAR1A gene confirming the diagnosis of Carney complex. Cushing's paper appears to be the first report of this complex.

DNA testing is now the preferred method of establishing a diagnosis for MEN 2B, and is thought to be almost 100% sensitive and specific. Gordon et al. reported cases of a difference disease—the "multiple mucosal neuroma syndrome"—having the physical phenotype of MEN2B, but without variations in the RET gene and without malignancy.

MEN2B should be entertained as a diagnosis whenever a person is found to have either medullary thyroid carcinoma or pheochromocytoma. Before DNA testing became available, measurement of serum calcitonin was the most important laboratory test for MEN2B. Calcitonin is produced by the "C" cells of the thyroid, which, because they are always hyperplastic or malignant in MEN2B, produce more calcitonin than normal. Calcitonin levels remain a valuable marker to detect recurrence of medullary thyroid carcinoma after thyroidectomy.

Luxol fast blue staining identifies myelin sheathing of some fibers, and lesional cells react immunohistochemically for S-100 protein, collagen type IV, vimentin, NSE, and neural filaments. More mature lesions will react also for EMA, indicating a certain amount of perineurial differentiation. Early lesions, rich in acid mucopolysaccharides, stain positively with alcian blue. When medullary thyroid cancer is present, levels of the hormone calcitonin are elevated in serum and urine. Under the microscope, tumors may closely resemble traumatic neuroma, but the streaming fascicles of mucosal neuroma are usually more uniform and the intertwining nerves of the traumatic neuroma lack the thick perineurium of the mucosal neuroma. Inflammatory cells are not seen in the stroma and dysplasia is not present in the neural tissues.

Diagnosis usually occurs upon investigation of a cause for already suspected Cushing's syndrome. High levels of cortisol observed in patients with PPNAD are not suppressed upon administration of dexamethasone (dexamethasone suppression test), and upon MRI or CT imaging, the pituitary will show no abnormalities. Measuring ACTH will confirm that the cause of the patients Cushing's syndrome is ACTH independent. The nature of Cushing's syndrome itself is periodic, which can make diagnosing PPNAD increasingly difficult.

Diagnosis of PPNAD can be difficult to determine preoperatively as CT scan findings can be variable ie appear normal or suggest unilateral adrenal lesions therefore impeding the correct diagnosis. NP-59 scintigraphy may be particularly useful in identifying the bilateral nature of the disease.

Gene studies are not necessary for diagnosis as there are clear gross and histological diagnostic markers, as the nodules can usually be seen clearly in both cases A positive family history of PPNAD has been shown to be associated with abnormal histological findings, e.g. mitotic figures, which may further hinder diagnosis. At the point where abdominal CT scanning and pituitary fossa MRI show no clear abnormalities, adrenalectomy may be performed.

Without treatment, persons with MEN2B die prematurely. Details are lacking, owing to the absence of formal studies, but it is generally assumed that death in the 30s is typical unless prophylactic thyroidectomy and surveillance for pheochromocytoma are performed (see below). The range is quite variable, however: death early in childhood can occur, and it is noteworthy that a few untreated persons have been diagnosed in their 50s. Recently, a larger experience with the disease "suggests that the prognosis in an individual patient may be better than previously considered."

Thyroidectomy is the mainstay of treatment, and should be performed without delay as soon as a diagnosis of MEN2B is made, even if no malignancy is detectable in the thyroid. Without thyroidectomy, almost all patients with MEN2B develop medullary thyroid cancer, in a more aggressive form than MEN 2A. The ideal age for surgery is 4 years old or younger, since cancer may metastasize before age 10.

Pheochromocytoma - a hormone secreting tumor of the adrenal glands - is also present in 50% of cases. Affected individuals are encouraged to get yearly screenings for thyroid and adrenal cancer.

Because prophylactic thyroidectomy improves survival, blood relatives of a person with MEN2B should be evaluated for MEN2B, even if lacking the typical signs and symptoms of the disorder.The mucosal neuromas of this syndrome are asymptomatic and self-limiting, and present no problem requiring treatment. They may, however, be surgically removed for aesthetic purposes or if they are being constantly traumatized.

A recommend surveillance program for Multiple Endocrine Neoplasia Type 1 has been suggested by the International Guidelines for Diagnosis and Therapy of MEN syndromes group.

Although there is no cure for 13q deletion syndrome, symptoms can be managed, usually with the involvement of a neurologist, rehabilitation physician, occupational therapist, physiotherapist, psychotherapist, nutritionist, special education professional, and/or speech therapist. If the affected child's growth is particularly slow, growth hormone treatment can be used to augment growth. Plastic surgeries can repair cleft palates, and surgical repair or monitoring by a pediatric cardiologist can manage cardiac defects. Some skeletal, neurological, genitourinary, gastrointestinal, and ophthalmic abnormalities can be definitively treated with surgery. Endocrine abnormalities can often be managed medically. Special educators, speech and occupational therapists, and physiotherapists can help a child develop skills in and out of school.

Treatment with isotretinoin may induce substantial resolution of skin lesions, but the risk of secondary infection remains.

In terms of diagnosis for this condition, the following methods/tests are available:

- Endoscopic

- CT scan

- Serum endocrine autoantibody screen

- Histologic test

Modeling EEC syndrome in vitro has been achieved by reprogramming EEC fibroblasts carrying mutations R304W and R204W into induced pluripotent stem cell (iPSC) lines. EEC-iPSC recapitulated defective epidermal and corneal fates. This model further identified PRIMA-1MET, a small compound that was identified as a compound targeting and reactivating p53 mutants based on a cell-based screening for rescuing the apoptotic activity of p53, as efficient to rescue R304W mutation defect. Of interest, similar effect had been observed on keratinocytes derived from the same patients. PRIMA-1MET could become an effective therapeutic tool for EEC patients.

Further genetic research is necessary to identify and rule out other possible loci contributing to EEC syndrome, though it seems certain that disruption of the p63 gene is involved to some extent. In addition, genetic research with an emphasis on genetic syndrome differentiation should prove to be very useful in distinguishing between syndromes that present with very similar clinical findings. There is much debate in current literature regarding clinical markers for syndromic diagnoses. Genetic findings could have great implications in clinical diagnosis and treatment of not only EEC, but also many other related syndromes.

Only symptomatic treatment for the management of disturbances can be indicated for affected individuals. The genetic origin of this disease would indicate gene therapy holds the most promise for future development of a cure. But at this time no specific treatments for Flynn–Aird syndrome exist.

Management of MEN2 patients includes thyroidectomy including cervical central and bilateral lymph nodes dissection for MTC, unilateral adrenalectomy for unilateral pheochromocytoma or bilateral adrenalectomy when both glands are involved and selective resection of pathologic parathyroid glands for primary hyperparathyroidism.

Familial genetic screening is recommended to identify at risk subjects who will develop the disease, permitting early management by performing prophylactic thyroidectomy, giving them the best chance of cure.

Prognosis of MEN2 is mainly related to the stage-dependant prognosis of MTC indicating the necessity of a complete thyroid surgery for index cases with MTC and the early thyroidectomy for screened at risk subjects.

While there is no cure for JBS, treatment and management of specific symptoms and features of the disorder are applied and can often be successful. Variability in the severity of JBS on a case-by-case basis determines the requirements and effectiveness of any treatment selected.

Pancreatic insufficiency and malabsorption can be managed with pancreatic enzyme replacement therapy, such as pancrelipase supplementation and other related methods.

Craniofacial and skeletal deformities may require surgical correction, using techniques including bone grafts and osteotomy procedures. Sensorineural hearing loss can be managed with the use of hearing aids and educational services designated for the hearing impaired.

Special education, specialized counseling methods and occupational therapy designed for those with mental retardation have proven to be effective, for both the patient and their families. This, too, is carefully considered for JBS patients.

Immunosuppressive therapy may be used in "type I" of this condition, ketoconazole can be used for "autoimmune polyendocrine syndrome type I" under certain conditions The component diseases are managed as usual, the challenge is to detect the possibility of any of the syndromes, and to anticipate other manifestations. For example, in a person with known Type 2 autoimmune polyendocrine syndrome but no features of Addison's disease, regular screening for antibodies against 21-hydroxylase may prompt early intervention and hydrocortisone replacement to prevent characteristic crises

Neurocristopathy is a diverse class of pathologies that may arise from defects in the development of tissues containing cells commonly derived from the embryonic neural crest cell lineage. The term was coined by Robert P. Bolande in 1974.

Accepted examples are piebaldism, Waardenburg syndrome, Hirschsprung disease, Ondine's curse (congenital central hypoventilation syndrome), pheochromocytoma, paraganglioma, Merkel cell carcinoma, multiple endocrine neoplasia, neurofibromatosis type I, CHARGE syndrome, familial dysautonomia, DiGeorge syndrome, Axenfeld-Rieger syndrome, Goldenhar syndrome (a.k.a. hemifacial microsomia), craniofrontonasal syndrome, congenital melanocytic nevus, melanoma, and certain congenital heart defects of the outflow tract, in particular.

Multiple sclerosis has also been suggested as being neurocristopathic in origin.

The usefulness of the definition resides in its ability to refer to a potentially common etiological factor for certain neoplasms and/or congenital malformation associations that are otherwise difficult to group with other means of nosology.

Johnson–McMillin syndrome is a neuroectodermal syndrome that consist of conductive hearing loss and microtia.

After diagnosis, it is important for patients to be continually monitored. The most common treatment for PPNAD is bilateral laparoscopic adrenalectomy; the process by which both adrenal glands are removed by a small incision.

Patients who have received this treatment will be prescribed mineralocorticoid and glucocorticoid steroids as they are no longer being naturally produced.

This is a treatment which has been used and refined since 1984.

Zunich–Kaye syndrome, also known as Zunich neuroectodermal syndrome, is a rare congenital ichthyosis first described in 1983. It is also referred to as CHIME syndrome, after its main symptoms (colobomas, heart defects, ichthyosiform dermatosis, intellectual disability, and either ear defects or epilepsy). It is a congenital syndrome with only a few cases studied and published.

This includes Chediak-Higashi syndrome and Elejalde syndrome (neuroectodermal melanolysosomal disease).

Before gene testing was available, the type and location of tumors determined which type of MEN2 a person had. Gene testing now allows a diagnosis before tumors or symptoms develop.

A table in the multiple endocrine neoplasia article compares the various MEN syndromes. MEN2 and MEN1 are distinct conditions, despite their similar names. MEN2 includes MEN2A, MEN2B and familial medullary thyroid cancer (FMTC).

The common feature among the three sub-types of MEN2 is a high propensity to develop medullary thyroid carcinoma.

Diagnosis for "type 1" of this condition for example, sees that the following methods/tests are available:

- Endoscopic

- CT scan

- Histologic test

Diagnostic testing in a possible paraneoplastic syndrome depends on the symptoms and the suspected underlying cancer.

Diagnosis may be difficult in patients in whom paraneoplastic antibodies cannot be detected. In the absence of these antibodies, other tests that may be helpful include MRI, PET, lumbar puncture and electrophysiology.

Carney triad (CT) is characterized by the coexistence of three types of neoplasms, mainly in young women, including gastric gastrointestinal stromal tumor, pulmonary chondroma, and extra-adrenal paraganglioma. The underlying genetic defect remains elusive. CT is distinct from Carney complex, and the Carney-Stratakis syndrome.

Multiple Endocrine Neoplasia type 1 (MEN1) is a rare hereditary endocrine cancer syndrome characterized primarily by tumors of the parathyroid glands (95% of cases), endocrine gastroenteropancreatic (GEP) tract (30-80% of cases), and anterior pituitary (15-90% of cases). Other endocrine and non-endocrine neoplasms including adrenocortical and thyroid tumors, visceral and cutaneous lipomas, meningiomas, facial angiofibromas and collagenomas, and thymic, gastric, and bronchial carcinoids also occur. The phenotype of MEN1 is broad, and over 20 different combinations of endocrine and non-endocrine manifestations have been described. MEN1 should be suspected in patients with an endocrinopathy of two of the three characteristic affected organs, or with an endocrinopathy of one of these organs plus a first-degree relative affected by MEN1 syndrome.

MEN1 patients usually have a family history of MEN1. Inheritance is autosomal dominant; any affected parent has a 50% chance to transmit the disease to his or her progeny. MEN1 gene mutations can be identified in 70-95% of MEN1 patients.

Many endocrine tumors in MEN1 are benign and cause symptoms by overproduction of hormones or local mass effects, while other MEN1 tumors are associated with an elevated risk for malignancy. About one third of patients affected with MEN1 will die early from an MEN1-related cancer or associated malignancy. Entero-pancreatic gastrinomas and thymic and bronchial carcinoids are the leading cause of morbidity and mortality. Consequently, the average age of death in untreated individuals with MEN1 is significantly lower (55.4 years for men and 46.8 years for women) than that of the general population.