| Superficial spreading melanoma | |
|---|---|
| Other names | Superficially spreading melanoma [1] |
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| Specialty | Dermatology |
Superficial spreading melanoma (SSM) is usually characterized as the most common form of cutaneous melanoma [2] in Caucasians. The average age at diagnosis is in the fifth decade, and it tends to occur on sun-exposed skin, especially on the backs of males and lower limbs of females.
Often, this disease evolves from a precursor lesion, usually a dysplastic nevus. Otherwise it arises in previously normal skin. A prolonged radial growth phase, where the lesion remains thin, may eventually be followed by a vertical growth phase where the lesion becomes thick and nodular. As the risk of spread varies with the thickness, early SSM is more frequently cured than late nodular melanoma.
The microscopic hallmarks are:
Treatment is by excisional biopsy, wide local excision and possibly sentinel node biopsy. Localized melanoma, which has not spread beyond the skin, has a very good prognosis with low recurrence rates. Spread of disease to local lymph nodes or distant sites (typically brain, bone, skin and lung) marks a decidedly poor prognosis.
A melanocytic nevus is a type of melanocytic tumor that contains nevus cells. Some sources equate the term mole with "melanocytic nevus", but there are also sources that equate the term mole with any nevus form.
Squamous-cell skin cancer, also known as cutaneous squamous-cell carcinoma (cSCC), is one of the main types of skin cancer along with basal cell cancer, and melanoma. It usually presents as a hard lump with a scaly top but can also form an ulcer. Onset is often over months. Squamous-cell skin cancer is more likely to spread to distant areas than basal cell cancer. When confined to the outermost layer of the skin, a precancerous or in situ form of cSCC is known as Bowen's disease.
Basal-cell carcinoma (BCC), also known as basal-cell cancer, is the most common type of skin cancer. It often appears as a painless raised area of skin, which may be shiny with small blood vessels running over it. It may also present as a raised area with ulceration. Basal-cell cancer grows slowly and can damage the tissue around it, but it is unlikely to spread to distant areas or result in death.
In medicine, Breslow's depth was used as a prognostic factor in melanoma of the skin. It is a description of how deeply tumor cells have invaded. Currently, the standard Breslow's depth has been replaced by the AJCC depth, in the AJCC staging system of melanoma. Originally, Breslow's depth was divided into 5 stages.
Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin but may rarely occur in the mouth, intestines or eye. In women, they most commonly occur on the legs, while in men they most commonly occur on the back. About 25% of melanomas develop from moles. Changes in a mole that can indicate melanoma include an increase in size, irregular edges, change in color, itchiness or skin breakdown.
Melanoma is a group of serious skin cancers that arise from pigment cells (melanocytes); acral lentiginous melanoma is a kind of lentiginous skin melanoma. Acral lentiginous melanoma is the most common subtype in people with darker skins and is rare in people with lighter skin types. Acral lentiginous melanoma is observed on the palms, soles, under the nails and in the oral mucosa. It occurs on non-hair-bearing surfaces of the body, which have not necessarily been exposed to sunlight. It is also found on mucous membranes. It is the most common form of melanoma diagnosed amongst Asian and sub-Saharan African ethnic groups. The average age at diagnosis is between sixty and seventy years.
A mastocytoma or mast cell tumor is a type of round-cell tumor consisting of mast cells. It is found in humans and many animal species; it also can refer to an accumulation or nodule of mast cells that resembles a tumor.
A dysplastic nevus or atypical mole is a nevus (mole) whose appearance is different from that of common moles. In 1992, the NIH recommended that the term "dysplastic nevus" be avoided in favor of the term "atypical mole". An atypical mole may also be referred to as an atypical melanocytic nevus, atypical nevus, B-K mole, Clark's nevus, dysplastic melanocytic nevus, or nevus with architectural disorder.
Dysplastic nevus syndrome, also known as familial atypical multiple mole–melanoma (FAMMM) syndrome, is an inherited cutaneous condition described in certain families, and characterized by unusual nevi and multiple inherited melanomas. First described in 1820, the condition is inherited in an autosomal dominant pattern, and caused by mutations in the CDKN2A gene. In addition to melanoma, individuals with the condition are at increased risk for pancreatic cancer.
Nodular melanoma (NM) is the most aggressive form of melanoma. It tends to grow more rapidly in thickness than in diameter compared to other melanoma subtypes. Instead of arising from a pre-existing mole, it may appear in a spot where a lesion did not previously exist. Since NM tends to grow in depth more quickly than it does in width, and can occur in a place that did not have a previous lesion, the prognosis is often worse because it takes longer for a person to be aware of the changes. NM is most often darkly pigmented; however, some NM lesions can be light brown, multicolored or even colorless (non-pigmented). A light-colored or non-pigmented NM lesion may escape detection because the appearance is not alarming, however an ulcerated and/or bleeding lesion is common. Polypoid melanoma is a virulent variant of nodular melanoma.
Lentigo maligna melanoma is a melanoma that has evolved from a lentigo maligna, as seen as a lentigo maligna with melanoma cells invading below the boundaries of the epidermis. They are usually found on chronically sun damaged skin such as the face and the forearms of the elderly.
Extramammary Paget’s Disease (EMPD), is a rare and slow-growing malignancy which occurs within the epithelium and accounts for 6.5% of all Paget’s disease. The clinical presentation of this disease is similar to the characteristics of mammary Paget’s disease (MPD). However, unlike MPD, which occurs in large lactiferous ducts and then extends into the epidermis, EMPD originates in glandular regions rich in apocrine secretions outside the mammary glands. EMPD incidence is increasing by 3.2% every year, affecting hormonally-targeted tissues such as the vulva and scrotum. In women, 81.3% of EMPD cases are related to the vulva, while for men, 43.2% of the manifestations present at the scrotum.
Vulvar cancer is a cancer of the vulva, the outer portion of the female genitals. It most commonly affects the labia majora. Less often, the labia minora, clitoris, or vaginal glands. Symptoms include a lump, itchiness, changes in the skin, or bleeding from the vulva.
Skin biopsy is a biopsy technique in which a skin lesion is removed to be sent to a pathologist to render a microscopic diagnosis. It is usually done under local anesthetic in a physician's office, and results are often available in 4 to 10 days. It is commonly performed by dermatologists. Skin biopsies are also done by family physicians, internists, surgeons, and other specialties. However, performed incorrectly, and without appropriate clinical information, a pathologist's interpretation of a skin biopsy can be severely limited, and therefore doctors and patients may forgo traditional biopsy techniques and instead choose Mohs surgery. There are four main types of skin biopsies: shave biopsy, punch biopsy, excisional biopsy, and incisional biopsy. The choice of the different skin biopsies is dependent on the suspected diagnosis of the skin lesion. Like most biopsies, patient consent and anesthesia are prerequisites.
Clear cell sarcoma is a rare form of cancer called a sarcoma. It is known to occur mainly in the soft tissues and dermis. Rare forms were thought to occur in the gastrointestinal tract before they were discovered to be different and redesignated as GNET.
Pseudomelanoma is a cutaneous condition in which melanotic skin lesions clinically resemble a superficial spreading melanoma at the site of a recent shave removal of a melanocytic nevus.
A malignant chondroid syringoma is a very uncommon cutaneous (skin) condition characterised by an adnexal eccrine tumour.
Histiocytic diseases in dogs are a group of diseases in dogs which may involve the skin, and which can be difficult to differentiate from granulomatous, reactive inflammatory or lymphoproliferative diseases. The clinical presentation and behaviour as well as response to therapy vary greatly among the syndromes.
Skin cancer, or neoplasia, is the most common type of cancer diagnosed in horses, accounting for 45 to 80% of all cancers diagnosed. Sarcoids are the most common type of skin neoplasm and are the most common type of cancer overall in horses. Squamous-cell carcinoma is the second-most prevalent skin cancer, followed by melanoma. Squamous-cell carcinoma and melanoma usually occur in horses greater than 9-years-old, while sarcoids commonly affect horses 3 to 6 years old. Surgical biopsy is the method of choice for diagnosis of most equine skin cancers, but is contraindicated for cases of sarcoids. Prognosis and treatment effectiveness varies based on type of cancer, degree of local tissue destruction, evidence of spread to other organs (metastasis) and location of the tumor. Not all cancers metastasize and some can be cured or mitigated by surgical removal of the cancerous tissue or through use of chemotherapeutic drugs.
Conjunctival squamous cell carcinoma and corneal intraepithelial neoplasia comprise what are called ocular surface squamous cell neoplasias. SCC is the most common malignancy of the conjunctiva in the US, with a yearly incidence of 1-2.8 per 100,000. Risk factors for the disease are exposure to sun, exposure to UVB, and light-colored skin. Other risk factors include radiation, smoking, HPV, arsenic, and exposure to polycyclic hydrocarbons.
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