Hemangioma - Benign tumor, usually in the shape of a ball, but sometimes a flatter mat, formed by a collection of excess blood vessels in an area. Because blood vessel cells are usually transparent in thin smooth muscle cells, hemangiomas are usually the color of the blood that runs through them. If the blood has a lot of oxygen, or is more arterial, the color is usually bright red. If the color is dark, the blood is usually low in oxygen, venous or possibly stagnated.

Histology - The microscopic examination of individual tiny cells.

Histopathologist ­ Literally, one who studies tissue with a microscope. This all-encompassing term may include dermatologists, general pathologists and dermatopathologists. Not all of these specialties have the same experience with the same types of lesions. General pathologists spend much of their daily time in the hospital reading glass slides of internal organ specimens. Dermatopathologists and dermatologists mostly concentrate on skin and may be better trained in reading skin-tissue specimens from reading the most recent literature specific to their field, the skin. Nonetheless, the quality level of general pathologists like everything else runs the spectrum from poor to excellent; some general pathologists who specialize in melanoma and know it better than many dermatologists or dermatopathologists. The patient must do quite a bit of homework to determine the quality of a given histopathologist's specialization.

Horizontal section - A specimen of skin taken parallel to and just below the skin's surface, then tested with cellular stains and examined with a microscope. A thin horizontal section could be considered a shave excision and a thicker section could, if processed properly with correct edge orientation and staining, be considered Mohs Surgery, depending on the surgeon's training. Horizontal sections can show the entire contact edge of the tissue from which the specimen was taken. If a process (tumor or abnormal growth) involves the edges of the tested specimen, then it is highly likely that the process, be it tumor or abnormal growth, involves the edges of the tissue that remained behind in the body where the specimen was taken. In that case, further horizontal sections are taken until no tumor is detected. Horizontal sections can test the entire perimeter of a specimen; such sections have a very low failure or uncertainty rate when the Mohs form of horizontal sectioning is performed. If processed properly by the Mohs method, horizontal sections can become a highly accurate two-dimensional representation of a three-dimensional problem (problem, tumor or abnormal growth. See Mohs Surgery.

Horny layer - A term meaning the same thing as the stratum corneum. See Stratum corneum in the glossary.

Incisional biopsy - The taking of a piece of a tissue smaller than the skin area in question (lesion) in order to get an idea of what the process (tumor or abnormal growth) is. The specimen is examined under the microscope, usually after it is stained with special dyes that usually display the nucleus and nuclear material, as well as other parts of the cell(s). Incisional biopsy techniques include punching with a miniature cookie-cutter-like instrument, shaving, snipping with scissors, the author's special inverted pyramidal biopsy technique and partial scalpel sampling.

Insured Benefit ­ The payment by an insurance company for a covered procedure or examination. In these days of managed care and treatment, insurance companies have deliberately contrived gray zones regarding coverage of both diseases and treatments. Different insurance companies and, in many instances, different policies/plans issued by the same insurance company, vary tremendously in approving a given treatment. Currently, in America, difficult battles have been required in order to obtain coverage for many legitimate, truly necessary procedures. The possibly deliberate time delays involved in fighting the companies for coverage have injured and killed patients in the past. The time delays will continue to harm patients in the future as long as wealthy insurance companies can provide money to powerful politicians who protect the insurance companies with special laws like ERISA.

Interferon therapy - Interferon is a natural chemical made by white blood cells to combat abnormal cells and communicate with healthy cells. Interferon has been shown to prolong the survival of melanoma patients. Interferon has been shown, as well, to have some limited effect against the least aggressive forms of basal- and squamous-cell carcinoma when injected into the skin over a certain period of time. This type of therapy may be helpful, for example, if a young fashion model does not wish to have surgery on a very superficial well-defined basal-cell cancer on the nose. However, the author believes that anyone receiving interferon therapy should be observed closely for many years to see whether or not the tumor is returning deeply so it may be stopped with other methods if the tumor is seen and is proven to have returned. It is not advisable to do technical studies, like biopsies, unless the naked eye reveals an abnormality or a bump that can be felt arises.

In situ ­ Used in dermatology and this Web site to mean intraepithelial or inside. Used in other contexts to mean the original or normal position of something. See Intraepithelial in the glossary.

Intraepithelial ­ Occurring within the epidermis or outer layer of the skin. Intraepithelial implies that the process (tumor, problem or growth) is completely contained in that upper layer (epidermis) and has not invaded or gone into the dermis. The term in situ is also used to indicate that a process is intraepithelial.

Intraepithelial squamous-cell carcinoma - Also known as Bowen's disease. Please see Bowen's Disease in glossary and in Web-site text.

Inverted pyramidal biopsy - A biopsy technique developed by the Web-site author that allows the surgeon to take biopsies as small as a pinhead to diagnose many skin cancers and as large as 8mm to diagnose atypical moles or melanoma. The shape of the biopsy is an inverted pyramid with its base at the skin's surface. The apex of the pyramid is at the deepest portion of the biopsy, usually into the dermis. The apex is the smallest portion of the biopsy specimen. Therefore, because the small apex is taken from the tissues with the potential to scar (dermis), the amount of scarring or noticeable marking is greatly reduced. Scarring is minimized while a quality biopsy specimen allowing proper diagnosis is achieved. Inverted pyramidal biopsies taken to diagnose non-melanoma skin cancer average about one to one and half times the size of a pinhead. The final scar is often invisible to the naked eye. If magnification is used, the scar looks like a miniature "Mercedes symbol." Young fashion models and people in the public eye tend to favor this technique for skin cancer diagnosis or microscopic mole evaluation.

Keratin - A protein that forms the cytoskeleton (miniature skeleton within a cell) of the epidermal cells. Keratin filaments run within a cell from the inside of the outer membrane to weave a "basket" around the nucleus of the cell. Keratins are a principle part of the epidermis, hair, nails, horny tissues and enamel of the teeth. Keratin contains a high amount of sulfur because of the amino acid cystine. Keratin accounts for 30% of the cellular protein of living epidermal cells and 85% of cellular protein of the dead cells in the stratum corunem (scaly, dead or horny layer of the outer skin).

Keratoacanthoma - Also called "KA" by dermatologists. As the name implies, the lesion usually contains keratin and may look much like a red or pink volcano with an eruptive central plug of compact or fragmented scale. The KA is considered a form of squamous-cell carcinoma by most authorities. However, some doctors consider keratoacanthoma to be a disease of its own and not a malignancy. Indeed, in many cases, KA's behave in a rather benign fashion, neither locally destructive, nor invasive (spreading internally). Nevertheless, in medicine, we do not want to miss a potentially serious problem. Therefore, because many keratoacanthomas have been reported to invade deeply, grow rapidly and destroy body parts and important structures like the nose and eyes, certain KA's, behaving in certain ways, located in special areas, merit special attention. When any growth has even the uncommon potential to cause significant harm by invading locally or spreading distantly, that growth (in this case, KA) should be classified as skin cancer to alert doctors and the general public to be vigilant. Experts with thousands of cases of experience, however, many times can split hairs and predict which KA will cause trouble and which will not with about 98% accuracy. There is also a hereditary form of KA, as well as the eruptive form that can pop up with many KA lesions, especially on the arms and legs.

Lentigo - A freckle. Lentigos are very rarely malignant, only when they are a form of melanoma. Otherwise, most maturity (age-induced) lentigos are known as senile (old-age) lentigos. Senile lentigos are usually flat, light brown, very uniformly colored "liver spots" that are present on the arms, legs and hands of more mature patients. Other benign lentigos can be solar-induced (caused by the sun) in younger patients.

Lesion - A very non-specific term that can be used in many ways. This ambiguous term encompasses almost every process occurring on the skin, from allergy spots to skin cancers to moles. The author considers "lesion" a "wastebasket" or all-encompassing term because it describes almost any blemish on the skin. Medical practitioners who cannot accurately diagnose (put a proper medical term) on the true problem. Some Board Certified Plastic Surgeons frequently use the term "lesion" on the lab paperwork when they submit skin biopsies to labs for testing this may deprive the laboratory/pathologist of vital information when reading the specimen.

Liquid nitrogen - Liquid nitrogen, also known as LN2, is liquefied-nitrogen gas. It is the greatest component of the natural air we breathe. It exists at a temperature of -196 C. When a skin lesion is "frozen" with liquid nitrogen, the skin may reach extremely cold temperatures. It is usually the thawing process that damages the cells to be reduced or removed. Liquid nitrogen may be applied to the skin by spray bottle (canister), by cotton swab or by an intermediate transfer object other than swab to bring a low temperature to the skin lesion. Liquid nitrogen is commonly used to treat precancers, benign growths and skin cancers. Treatment with LN2 has varying degrees of failure and success depending upon the skill of the treating doctor.