The treatment of choice is percutaneous balloon valvuloplasty and is done when a resting peak gradient is seen to be >60mm Hg or a mean >40mm Hg is observed.

When pulmonic stenosis (PS) is present, resistance to blood flow causes right ventricular hypertrophy. If right ventricular failure develops, right atrial pressure will increase, and this may result in a persistent opening of the foramen ovale, shunting of unoxygenated blood from the right atrium into the left atrium, and systemic cyanosis. If pulmonary stenosis is severe, congestive heart failure occurs, and systemic venous engorgement will be noted. An associated defect such as a patent ductus arteriosus partially compensates for the obstruction by shunting blood from the left ventricle to the aorta then back to the pulmonary artery (as a result of the higher pressure in the left ventricle) and back into the lungs.

A compartment syndrome is an increased pressure within a muscular compartment that compromises the circulation to the muscles.

Diffuse tightness and tenderness over the entire belly of the tibialis anterior that does not respond to elevation or pain medication can be early warning signs and suggestive of Anterior Compartment Syndrome. Other common symptoms include excessive swelling that causes the skin to become hot, stretched and glossy. Pain, paresthesias, and tenderness in both the ischemic muscles and the region supplied by the deep common fibular nerve are exhibited by patients suffering from this condition. Sensitivity to passive stretch and active contraction are common, and tend to increase the symptoms.

Perlman syndrome is a rare disease with an estimated incidence of less than 1 in 1,000,000. As of 2008, less than 30 patients had ever been reported in the world literature.

The six-week period after pregnancy is called the postpartum stage. During this time, women are at increased risk of being constipated. Multiple studies estimate the prevalence of constipation to be around 25% during the first 3 months. Constipation can cause discomfort for women, as they are still recovering from the delivery process especially if they have had a perineal tear or underwent an episiotomy. Risk factors that increase the risk of constipation in this population include:

- Damage to the levator ani muscles (pelvic floor muscles) during childbirth

- Forceps-assisted delivery

- Lengthy second stage of labor

- Delivering a large child

- Hemorrhoids

Hemorrhoids are common in pregnancy and also may get exacerbated when constipated. Anything that can cause pain with stooling (hemorrhoids, perineal tear, episiotomy) can lead to constipation because patients may withhold from having a bowel movement so as to avoid pain.

The pelvic floor muscles play an important role in helping pass a bowel movement. Injury to those muscles by some of the above risk factors (examples- delivering a large child, lengthy second stage of labor, forceps delivery) can result in constipation. Women sometimes get enemas during labor that can also alter bowel movements in the days after having given birth. However, there is insufficient evidence to make conclusions about the effectiveness and safety of laxatives in this group of people.

Perlman syndrome is an uncommon genetic disorder grouped with overgrowth syndrome in which an abnormal increase is often noted at birth in the size of the body or a body part of the infant. The disorder, also called renal hamartomas, nephroblastomatosis and fetal gigantism, has also been grouped with Renal cell carcinoma. The characteristic features include polyhydramnios, fetal overgrowth, including macrocephaly, neonatal macrosomia, visceromegaly, dysmorphic facial features, and an increased risk for Wilms' tumor at an early age.

Approximately 3% of children have constipation, with girls and boys being equally affected. With constipation accounting for approximately 5% of general pediatrician visits and 25% of pediatric gastroenterologist visits, the symptom carries a significant financial impact upon the healthcare system. While it is difficult to assess an exact age at which constipation most commonly arises, children frequently suffer from constipation in conjunction with life-changes. Examples include: toilet training, starting or transferring to a new school, and changes in diet. Especially in infants, changes in formula or transitioning from breast milk to formula can cause constipation. Fortunately, the majority of constipation cases are not tied to a medical disease, and treatment can be focused on simply relieving the symptoms.

It is usually associated with amyloid beta.

However, there are other types:

- the "Icelandic type" is associated with Cystatin C

- the "British type" is associated with ITM2B

Research is currently being conducted to determine if there is a link between cerebral amyloid angiopathy and ingestion of excessive quantities of aluminum.

Susceptibility weighted imaging has been proposed as a tool for identifying CAA-related microhemorrhages.

Biopsies also play a role in diagnosing the condition.

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.

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.

Scott syndrome is a rare congenital bleeding disorder that is due to a defect in a platelet mechanism required for blood coagulation.

Normally when a vascular injury occurs, platelets are activated and phosphatidylserine (PS) in the inner leaflet of the platelet membrane is transported to the outer leaflet of the platelet membrane, where it provides a binding site for plasma protein complexes that are involved in the conversion of prothrombin to thrombin, such as factor VIIIa-IXa (tenase) and factor Va-Xa (prothrombinase).

In Scott syndrome, the mechanism for translocating PS to the platelet membrane is defective, resulting in impaired thrombin formation. A similar defect in PS translocation has also been demonstrated in Scott syndrome red blood cells and Epstein-Barr virus transformed lymphocytes, suggesting that the defect in Scott syndrome reflects a mutation in a stem cell that affects multiple hematological lineages.

The basis for the defect in PS translocation is, at present, unknown. A candidate protein, scramblase, that may be involved in this process appears to be normal in Scott syndrome platelets. Other possible defects in PS translocation, reported in some patients, require further study. The initially reported patient with Scott Syndrome has been found to have a mutation at a splice-acceptor site of the gene encoding transmembrane protein 16F (TMEM16F). At present, the only treatment for episodes of bleeding is the transfusion of normal platelets.

Crush syndrome (also traumatic rhabdomyolysis or Bywaters' syndrome) is a medical condition characterized by major shock and renal failure after a injury to skeletal muscle. Crush "injury" is compression of extremities or other parts of the body that causes muscle swelling and/or neurological disturbances in the affected areas of the body, while crush "syndrome" is localized crush injury with systemic manifestations. Cases occur commonly in catastrophes such as earthquakes, to victims that have been trapped under fallen or moving masonry.

Victims of crushing damage present some of the greatest challenges in field medicine, and may be among the few situations where a physician is needed in the field. The most drastic response to crushing under massive objects may be field amputation. Even if it is possible to extricate the patient without amputation, appropriate physiological preparation is mandatory: where permissive hypotension is the standard for prehospital care, fluid loading is the requirement in crush syndrome.

Seigo Minami, a Japanese physician, first reported the crush syndrome in 1923. He studied the pathology of three soldiers who died in World War I from insufficiency of the kidney. The renal changes were due to methemoglobin infarction, resulting from the destruction of muscles, which is also seen in persons who are buried alive. The progressive acute renal failure is because of acute tubular necrosis.

The syndrome was later described by British physician Eric Bywaters in patients during the 1941 London Blitz. It is a reperfusion injury that appears after the release of the crushing pressure. The mechanism is believed to be the release into the bloodstream of muscle breakdown products—notably myoglobin, potassium and phosphorus—that are the products of rhabdomyolysis (the breakdown of skeletal muscle damaged by ischemic conditions).

The specific action on the kidneys is not understood completely, but may be due partly to nephrotoxic metabolites of myoglobin.

The most devastating systemic effects can occur when the crushing pressure is suddenly released, without proper preparation of the patient, causing reperfusion syndrome. In addition to tissue directly suffering the crush mechanism, down stream tissue is subject to Ischemia-reperfusion injuries of the appendicular musculoskeletal system. Without proper preparation, the patient, with pain control, may be cheerful before extrication, but die shortly thereafter. This sudden decompensation is called the "smiling death."

These systemic effects are caused by a traumatic rhabdomyolysis. As muscle cells die, they absorb sodium, water and calcium; the rhabdomyolysis releases potassium, myoglobin, phosphate, thromboplastin, creatine and creatine kinase.

Compartment syndrome can be secondary to crush syndrome. Monitor for the classic 5 Ps: pain, pallor, parasthesias, pain with passive movement, and pulselessness.

The presence of HPV within the tumour has been realised to be an important factor for predicting survival since the 1990s. Tumor HPV status is strongly associated with positive therapeutic response and survival compared with HPV-negative cancer, independent of the treatment modality chosen and even after adjustment for stage. While HPV+OPC patients have a number of favourable demographic features compared to HPV-OPC patients, such differences account for only about ten per cent of the survival difference seen between the two groups. Response rates of over 80% are reported in HPV+ cancer and three-year progression free survival has been reported as 75–82% and 45–57%, respectively, for HPV+ and HPV- cancer, and improving over increasing time. It is likely that HPV+OPC is inherently less maligant than HPV-OPC, since patients treated by surgery alone have a better survival after adjustment for stage. In one study, less than 50% of patients with HPV-OPC were still alive after five years, compared to more than 70% with HPV+OPC and an equivalent stage and disease burden.

In RTOG clinical trial 0129, in which all patients with advanced disease received radiation and chemotherapy, a retrospective analysis (recursive-partitioning analysis, or RPA) at three years identified three risk groups for survival (low, intermediate, and high) based on HPV status, smoking, T stage and N stage ("see" Ang et al., Fig. 2). HPV status was the major determinant of survival, followed by smoking history and stage. 64% were HPV+ and all were in the low and intermediate risk group, with all non-smoking HPV+ patients in the low risk group. 82% of the HPV+ patients were alive at three years compared to 57% of the HPV- patients, a 58% reduction in the risk of death. Locoregional failure is also lower in HPV+, being 14% compared to 35% for HPV-. HPV positivity confers a 50–60% lower risk of disease progression and death, but the use of tobacco is an independently negative prognostic factor. A pooled analysis of HPV+OPC and HPV-OPC patients with disease progression in RTOG trials 0129 and 0522 showed that although less HPV+OPC experienced disease progression (23 v. 40%), the median time to disease progression following treatment was similar (8 months). The majority (65%) of recurrences in both groups occurred within the first year after treatment and were locoregional. HPV+ did not reduce the rate of metastases (about 45% of patients experiencing progression), which are predominantly to the lungs (70%), although some studies have reported a lower rate. with 3-year distant recurrence rates of about 10% for patients treated with primary radiation or chemoradiation. Even if recurrence or metastases occur, HPV positivity still confers an advantage.

By contrast tobacco usage is an independently negative prognostic factor, with decreased response to therapy, increased disease recurrence rates and decreased survival. The negative effects of smoking, increases with amount smoked, particularly

if greater than 10 pack-years. For patients such as those treated on RTOG 0129 with primary chemoradiation, detailed nomograms have been derived from that dataset combined with RTOG 0522, enabling prediction of outcome based on a large number of variables. For instance, a 71 year old married non-smoking high school graduate with a performance status (PS) of 0, and no weight loss or anaemia and a T3N1 HPV+OPC would expect to have a progression-free survival of 92% at 2 years and 88% at 5 years. A 60 year old unmarried nonsmoking high school graduate with a PS of 1, weight loss and anaemia and a T4N2 HPV+OPC would expect to have a survival of 70% at two years and 48% at five years. Less detailed information is available for those treated primarily with surgery, for whom less patients are available, as well as low rates of recurrence (7–10%), but features that have traditionally been useful in predicting prognosis in other head and neck cancers, appear to be less useful in HPV+OPC. These patients are frequently stratified into three risk groups:

- Low risk: No adverse pathological features

- Intermediate risk: T3–T4 primary, perineural or lymphovascular invasion, N2 (AJCC 7)

- High risk: Positive margins, ECE

HPV+OPC patients are less likely to develop other cancers, compared to other head and neck cancer patients. A possible explanation for the favourable impact of HPV+ is "the lower probability of occurrence of 11q13 gene amplification, which is considered to be a factor underlying faster and more frequent recurrence of the disease" Presence of TP53 mutations, a marker for HPV- OPC, is associated with worse prognosis. High grade of p16 staining is thought to be better than HPV PCR analysis in predicting radiotherapy response.

HCC mostly occurs in people with cirrhosis of the liver, and so risk factors generally include factors which cause chronic liver disease that may lead to cirrhosis. Still, certain risk factors are much more highly associated with HCC than others. For example, while heavy alcohol consumption is estimated to cause 60-70% of cirrhosis, the vast majority of HCC occurs in cirrhosis attributed to viral hepatitis (although there may be overlap). Recognized risk factors include:

- Chronic viral hepatitis (estimated cause of 80% cases globally)

- Chronic hepatitis B (approximately 50% cases)

- Chronic hepatitis C (approximately 25% cases)

- Toxins:

- Alcohol abuse: the most common cause of cirrhosis

- Aflatoxin

- Iron overload state (Hemochromatosis)

- Metabolic:

- Nonalcoholic steatohepatitis: up to 20% progress to cirrhosis

- Type 2 diabetes (probably aided by obesity)

- Congenital disorders:

- Alpha 1-antitrypsin deficiency

- Wilson's disease (controversial; while some theorise the risk increases, case studies are rare and suggest the opposite where Wilson's disease actually may confer protection)

- Hemophilia, although statistically associated with higher risk of HCC, this is due to coincident chronic viral hepatitis infection related to repeated blood transfusions over lifetime.

The significance of these risk factors varies globally. In regions where hepatitis B infection is endemic, such as southeast China, this is the predominant cause. In populations largely protected by hepatitis B vaccination, such as the United States, HCC is most often linked to causes of cirrhosis such as chronic hepatitis C, obesity, and alcohol abuse.

Certain benign liver tumors, such as hepatocellular adenoma, may sometimes be associated with coexisting malignant HCC. There is limited evidence for the true incidence of malignancy associated with benign adenomas; however, the size of hepatic adenoma is considered to correspond to risk of malignancy and so larger tumors may be surgically removed. Certain subtypes of adenoma, particularly those with β-catenin activation mutation, are particularly associated with increased risk of HCC.

Children and adolescents are unlikely to have chronic liver disease, however, if they suffer from congenital liver disorders, this fact increases the chance of developing hepatocellular carcinoma. Specifically, children with biliary atresia, infantile cholestasis, glycogen-storage diseases, and other cirrhotic diseases of the liver are predisposed to developing HCC in childhood.

Young adults afflicted by the rare fibrolamellar variant of hepatocellular carcinoma may have none of the typical risk factors, i.e. cirrhosis and hepatitis.

Most mucosal squamous cell head and neck cancers, including oropharyngeal cancer (OPC), have historically been attributed to tobacco and alcohol use. However this pattern has changed considerably since the 1980s. It was realised that some cancers occur in the absence of these risk factors and

an association between human papilloma virus (HPV) and various squamous cell cancers, including OPC, was first described in 1983. Since then both molecular and epidemiological evidence has been accumulating, with the International Agency for Research on Cancer (IARC) stating that high-risk HPV types 16 and 18 are carcinogenic in humans, in 1995, and In 2007 that HPV was a cause for oral cancers. Human papillomavirus (HPV)-positive cancer (HPV+OPC) incidence has been increasing while HPV-negative (HPV-OPC) cancer incidence is declining, a trend that is estimated to increase further in coming years. Since there are marked differences in clinical presentation and treatment relative to HPV status, HPV+OPC is now viewed as a distinct biologic and clinical condition.

Human HPV has long been implicated in the pathogenesis of several anogenital cancers including those of the anus, vulva, vagina, cervix, and penis. In 2007 it was also implicated by both molecular and epidemiological evidence in cancers arising outside of the anogenital tract, namely oral cancers. HPV infection is common among healthy individuals, and is acquired largely through sexual contact. Although less data is available, prevalence of HPV infection is at least as common among men as among women, with 2004 estimates of about 27% among US women aged 14–59.

HPV oral infection precedes the development of HPV+OPC. Slight injuries in the mucous membrane serve as an entry gate for HPV, which thus works into the basal layer of the epithelium. People testing positive for HPV type 16 virus (HPV16) oral infection have a 14 times increased risk of developing HPV+OPC. Immunosuppression seems to be an increased risk factor for HPV+OPC. Individuals with TGF-β1 genetic variations, specially T869C, are more likely to have HPV16+OPC. TGF-β1 plays an important role in controlling the immune system. In 1993 it was noted that patients with human papillomavirus (HPV)-associated anogenital cancers had a 4-fold increased risk of tonsillar squamous-cell carcinoma. Although evidence suggests that HPV16 is the main cause of OPC in humans not exposed to smoking and alcohol, the degree to which tobacco and/or alcohol use may contribute to increase the risk of HPV+OPC has not always been clear but it appears that both smoking and HPV infection are independent and additive risk factors for developing OPC. Human herpesvirus-8 infection can potentiate the effects of HPV-16.

Risk factors include a high number of sexual partners (25% increase >= 6 partners), a history of oral-genital sex (125% >= 4 partners), or anal–oral sex, a female partner with a history of either an abnormal Pap smear or cervical dysplasia, chronic periodontitis, and, among men, decreasing age at first intercourse and history of genital warts.

Progeroid syndromes (PS) are a group of rare genetic disorders which mimic physiological aging, making affected individuals appear to be older than they are. The term "progeroid syndrome" does not necessarily imply progeria (Hutchinson–Gilford progeria syndrome), which is a specific type of progeroid syndrome.

"Progeroid" means "resembling premature aging", a definition that can apply to a broad range of diseases. Familial Alzheimer's disease and familial Parkinson's disease are two well-known accelerated-aging diseases that are more frequent in older individuals. They affect only one tissue and can be classified as unimodal progeroid syndromes. Segmental progeria, which is more frequently associated with the term "progeroid syndrome", tends to affect multiple or all tissues while causing affected individuals to exhibit only some of the features associated with aging.

All disorders within this group are thought to be monogenic, meaning they arise from mutations of a single gene. Most known PS are due to genetic mutations that lead to either defects in the DNA repair mechanism or defects in lamin A/C.

Examples of PS include Werner syndrome (WS), Bloom syndrome (BS), Rothmund–Thomson syndrome (RTS), Cockayne syndrome (CS), xeroderma pigmentosum (XP), trichothiodystrophy (TTD), combined xeroderma pigmentosum-Cockayne syndrome (XP-CS), restrictive dermopathy (RD), and Hutchinson–Gilford progeria syndrome (HGPS). Individuals with these disorders tend to have a reduced lifespan. Progeroid syndromes have been widely studied in the fields of aging, regeneration, stem cells, and cancer. The most widely studied of the progeroid syndromes are Werner syndrome and Hutchinson–Gilford progeria, as they are seen to most resemble natural aging.

In contrast to cutaneous LP, which is self limited, lichen planus lesions in the mouth may persist for many years, and tend to be difficult to treat, with relapses being common. Atrophic/erosive lichen planus is associated with a small risk of cancerous transformation, and so people with OLP tend to be monitored closely over time to detect any potential change early. Sometimes OLP can become secondarily infected with Candida organisms.

The overall prevalence of lichen planus in the general population is about 0.1–4.0%. It generally occurs more commonly in females, in a ratio of 3:2, and most cases are diagnosed between the ages of 30 and 60, but it can occur at any age.

Oral lichen planus is relatively common, It is one of the most common mucosal diseases. The prevalence in the general population is about 1.27–2.0%, and it occurs more commonly in middle aged people. OLP in children is rare. About 50% of females with oral lichen planus were reported to have undiagnosed vulvar lichen planus.

The risk of hepatocellular carcinoma in type 2 diabetics is greater (from 2.5 to 7.1 times the non diabetic risk) depending on the duration of diabetes and treatment protocol. A suspected contributor to this increased risk is circulating insulin concentration such that diabetics with poor insulin control or on treatments that elevate their insulin output (both states that contribute to a higher circulating insulin concentration) show far greater risk of hepatocellular carcinoma than diabetics on treatments that reduce circulating insulin concentration. On this note, some diabetics who engage in tight insulin control (by keeping it from being elevated) show risk levels low enough to be indistinguishable from the general population. This phenomenon is thus not isolated to diabetes mellitus type 2 since poor insulin regulation is also found in other conditions such as metabolic syndrome (specifically, when evidence of non alcoholic fatty liver disease or NAFLD is present) and again there is evidence of greater risk here too. While there are claims that anabolic steroid abusers are at greater risk (theorized to be due to insulin and IGF exacerbation), the only evidence that has been confirmed is that anabolic steroid users are more likely to have hepatocellular adenomas (a benign form of HCC) transform into the more dangerous hepatocellular carcinoma.

"Wiedemann–Rautenstrauch (WR) syndrome", also known as "neonatal progeroid syndrome", is an autosomal recessive progeroid syndrome. More than 30 cases have been reported. Most affected individuals die by seven months of age, but some do survive into their teens.

WR is associated with abnormalities in bone maturation, and lipids and hormone metabolism. Affected individuals exhibit intrauterine and postnatal growth retardation, leading to short stature and an aged appearance from birth. They have physical abnormalities including a large head (macrocephaly), sparse hair, prominent scalp veins, inward-folded eyelids, widened anterior fontanelles, hollow cheeks (malar hypoplasia), general loss of fat tissues under the skin, delayed tooth eruption, abnormal hair pattern, beaked noses, mild to severe mental retardation and dysmorphism.

The cause of WR is unknown, although defects in DNA repair have been implicated.

It is possible to classify epidermolytic hyperkeratosis based upon palm and sole hyperkeratosis.

This is a dominant genetic condition caused by mutations in the genes encoding the proteins keratin 1 or keratin 10.

- Keratin 1 is associated with the variants affecting the palms and soles.

- Keratin 10 is associated with the variants in which these are unaffected.

Epidermolytic ichthyosis (EI), (also known as "epidermolytic hyperkeratosis (EHK)", "bullous congenital ichthyosiform erythroderma (BCIE), bullous ichthyosiform erythroderma, or bullous congenital ichthyosiform erythroderma Brocq) is a rare and severe form of ichthyosis this skin disease affects around 1 in 300,000 people.

It involves the clumping of keratin filaments.