Mutation of the MDM2 SNP309 gene is associated with increased risks for younger women.Fair- and red-haired people, persons with multiple atypical nevi or dysplastic nevi and persons born with giant congenital melanocytic nevi are at increased risk.A family history of melanoma greatly increases a persons risk, because mutations in several genes have been found in melanoma-prone families. People with a history of one melanoma are at increased risk of developing a second primary tumor.Fair skin is the result of having less melanin in the skin, which means less protection from UV radiation exists. A family history could indicate a genetic predisposition to melanoma. Pathophysiology
The earliest stage of melanoma starts when melanocytes begin out-of-control growth. Melanocytes are found between the outer layer of the skin (the epidermis) and the next layer (the dermis). This early stage of the disease is called the radial growth phase, when the tumor is less than 1 mm thick, and spreads at the level of the basal epidermis. Because the cancer cells have not yet reached the blood vessels deeper in the skin, it is very unlikely that this early-stage melanoma will spread to other parts of the body. If the melanoma is detected at this stage, then it can usually be completely removed with surgery.When the tumor cells start to move in a different direction – vertically up into the epidermis and into the papillary dermis – cell behaviour changes dramatically.The next step in the evolution is the invasive radial growth phase, in which individual cells start to acquire invasive potential.
Neutropenic enterocolitis is inflammation of the cecum (part of the large intestine) that may be associated with infection. It is particularly associated with neutropenia, a low level of neutrophil granulocytes (the most common form of white blood cells) in the blood. Signs and symptoms
Signs and symptoms of typhlitis may include diarrhea, a distended abdomen, fever, chills, nausea, vomiting, and abdominal pain or tenderness. Cause
The condition is usually caused by Gram-positive enteric commensal bacteria of the gut (gut flora). Clostridium difficile is a species of Gram-positive bacteria that commonly causes severe diarrhea and other intestinal diseases when competing bacteria are wiped out by antibiotics, causing pseudomembranous colitis, whereas Clostridium septicum is responsible for most cases of neutropenic enterocolitis.Typhlitis most commonly occurs in immunocompromised patients, such as those undergoing chemotherapy,  patients with AIDS, kidney transplant patients, or the elderly. Diagnosis
Typhlitis is diagnosed with a radiograph CT scan showing thickening of the cecum and "fat stranding". Treatment
Typhlitis is a medical emergency and requires prompt management. Untreated typhlitis has a poor prognosis, particularly if associated with pneumatosis intestinalis (air in the bowel wall) and/or bowel perforation, and has significant morbidity unless promptly recognized and aggressively treated.Successful treatment hinges on:
Early diagnosis provided by a high index of suspicion and the use of CT scanning
Nonoperative treatment for uncomplicated cases
Empiric antibiotics, particularly if the patient is neutropenic or at other risk of infection.In rare cases of prolonged neutropenia and complications such as bowel perforation, neutrophil transfusions can be considered but have not been studied in a randomized control trial.