A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, when it may be called a tumor.ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology. Prior to the abnormal growth of tissue, as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia. However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word is from Ancient Greek νέος- neo new and πλάσμα plasma formation, creation. Types
A neoplasm can be benign, potentially malignant, or malignant (cancer). Benign tumors include uterine fibroids, osteophytes and melanocytic nevi (skin moles). They are circumscribed and localized and do not transform into cancer. Potentially-malignant neoplasms include carcinoma in situ. They are localised, do not invade and destroy but in time, may transform into a cancer. Malignant neoplasms are commonly called cancer. They invade and destroy the surrounding tissue, may form metastases and, if untreated or unresponsive to treatment, will generally prove fatal.
Hot tub folliculitis (pseudomonal folliculitis) is a common type of folliculitis, a condition which causes inflammation of hair follicles. : 272 This condition is caused by an infection of hair follicles by a non-pathogenic strain of the bacterium Pseudomonas aeruginosa. The bacterium is commonly found in hot tubs, water slides, and rarely in swimming pools. Children are more prone because they typically stay in the water longer than adults. Hot tub folliculitis appears on the skin in the form of a rash, roughly resembling chicken pox and then develops further to appear as a pimple. Hot tub folliculitis can be extremely painful and/or itchy, and left alone without scratching will go away much more quickly. If the rash is aggravated, it can stay, worsen, and spread, lasting for months. By that time, it is much more difficult to treat. In an immunocompetent person, the rash is self-limited and will usually resolve after about 7 to 10 days but the condition can leave a hyperpigmented lesion that goes away after a few months.Normally, the rash does not need specific treatment and will go away on its own. Antibiotics may be prescribed in some cases. If the rash continues to appear longer than the 7- to 10-day time period, a physician should be consulted. Folliculitis that is not treated properly could worsen and cause abscesses. See also
Skin lesion


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