Neoplasms of the Skin

A precancerous skin lesion, often linked to prolonged sun exposure. A small percentage may progress to squamous cell carcinoma if left untreated.

A type of skin cancer that originates in the squamous cells of the epidermis. It typically appears as a scaly, reddish plaque or nodule.

A type of skin cancer that originates in the squamous cells of the epidermis. It is characterized by abnormal keratinocytes, involving the full thickness of the epidermis, and mitosis throughout the epidermis.

A type of skin cancer that originates in the squamous cells of the epidermis and has spread to the dermis or subcutis. It is characterized by atypical keratinocytes proliferating and invading deeper tissue.

A benign melanocytic nevus (mole) where the melanocytes are located within the epidermis and dermis.

A benign melanocytic nevus (mole) where the melanocytes are located only within the dermis.

A benign skin growth characterized by a symmetrical shape, mature melanocytes, minimal cell abnormalities, and rare cell division.

A type of skin cancer that develops from melanocytes, which are the cells that produce pigment.

The most common type of melanoma, accounting for nearly 70% of cases.

A type of melanoma that appears as a raised nodule.

A type of melanoma that occurs mainly on the trunk of the body.

A type of melanoma that often occurs in the hands, soles of feet, and mucous membranes.

A flat, wart-like growth on the skin that is usually harmless. It can be light tan/pink to dark brown/gray, but doesn't have a true pigment pattern.

A characteristic feature of seborrheic keratoses where the keratinocytes are arranged in a rope-like pattern.

A common, benign growth of skin cells (keratinocytes) that often occurs on the face, neck, and upper chest.

A benign, non-cancerous growth of skin tissue (derived from melanocytes) that often appears as a brown, flat or raised spot.

These cells do not show any signs of cancer, such as abnormal growth (atypia) or increased cell division (mitoses).

The cells in seborrheic keratosis are arranged in a characteristic rope-like pattern, suggesting a "string" appearance.

These are benign proliferations of melanocytes.

A type of benign skin lesion that is often brown and may be flat or raised.

Acral lentiginous melanoma (ALM) is a subtype of melanoma that primarily occurs in darker-skinned individuals.

Pagetoid spread describes the upward migration of melanoma cells within the epidermis, spreading horizontally and creating a characteristic pattern.

Melanoma cells don't mature deeply as they grow, maintaining an immature appearance, unlike nevi.

The presence of mitoses (cell division) in melanoma indicates a higher risk of aggressive growth.

The depth of invasion, measured using the Breslow thickness, is the most critical factor determining melanoma prognosis.

BRAF V600E is a common genetic mutation found in melanoma, which can be targeted by specific therapies.

BRAF inhibitors like Vemurafenib and Dabrafenib are used to target specific melanoma mutations, potentially benefiting patients with metastatic or unresectable melanoma.

The most common type of skin cancer, Basal Cell Carcinoma (BCC) is typically diagnosed through a biopsy.

Basal Cell Carcinoma (BCC) is a type of skin cancer that arises from the basal layer of the epidermis. It is characterized by slow growth and rarely metastasizes. BCC is commonly found on sun-exposed areas of the body and often presents as a pearly or shiny papule with telangiectasias (tiny dilated blood vessels).

The histological appearance of BCC reveals nests of basaloid cells. These cells are small and have a dark-staining nucleus, resembling the basal layer of the epidermis.

BCC is characterized by nests of basaloid cells with a darkly stained nucleus.

Actinic keratosis (AK) is a precancerous skin lesion caused by sun exposure. It typically appears as a rough, scaly, or crusty patch on the skin. AK can transform into squamous cell carcinoma (SCC) if left untreated.

The histological appearance of AK reveals abnormal cells with atypical features. The severity of these changes can vary, and some AKs may have more concerning features.

Approximately 10% of AKs can progress to squamous cell carcinoma over time if left untreated. It is important to monitor AKs and seek treatment to prevent the development of more serious skin cancers.

While BCC is the most common type of skin cancer, it is generally considered less aggressive than melanoma. Although it may invade surrounding tissues, metastatic spread to distant organs is rare.

The risk of developing BCC is significantly increased by sun exposure. Genetics may also play a role, with some individuals having an increased susceptibility to this type of skin cancer.

A rare genetic disorder causing a deficiency in DNA repair, leading to increased sensitivity to sunlight and a high risk of skin cancers.

A syndrome characterized by multiple basal cell carcinomas (BCCs), odontogenic keratocysts, and skeletal abnormalities. It is associated with a mutation in the PTCH gene.

A genetic condition that causes unusual moles (nevi) and a significantly increased risk of melanoma. It is often associated with mutations in the CDKN2A gene.

A common benign vascular tumor that develops on the skin, often after minor trauma or exposure to foreign bodies. It appears as a bright red, soft nodule.

The most common vascular tumor of infancy, typically appearing within weeks of birth. It's more common in Caucasian girls, premature infants, and those with placental abnormalities.

A type of infantile hemangioma characterized by small, well-defined, bright red nodules that resemble strawberries. They are raised and soft to the touch.

A type of infantile hemangioma located deeper in the dermis or subcutaneous fat. It appears as a bluish, poorly defined, firm nodule.

A type of infantile hemangioma that combines features of both superficial and deep hemangiomas.

A common, benign vascular tumor in adults, typically appearing as small, dome-shaped, red papules. They are most common on the trunk and upper arms.

A type of cancer that affects blood vessels and lymph vessels. It typically presents as purplish or brown patches on the skin. It can be associated with the HHV-8 virus.

A common type of basal cell carcinoma, a slow-growing skin cancer. It typically appears as a pearly or waxy bump with small blood vessels.

Melanomas are of most concern due their high chances of spreading, unlike benign nevi.

Melanoma cells don't mature deeply as they grow, retaining an immature appearance. This is unlike nevi, which mature with depth.

A type of skin cancer that originates in the basal layer of the epidermis, often caused by sun exposure. It's characterized by slow growth and rarely spreads to other parts of the body. It usually appears as a pearly or waxy bump, often with small blood vessels.

Basal cell carcinoma is characterized by nests of basaloid cells that are small and have a dark-staining nucleus, resembling the basal layer of the epidermis.

It involves an accumulation of abnormal cells with varying levels of atypia, which can range from mild to severe.

If left untreated, about 10% of actinic keratoses can transform into squamous cell carcinoma.

It is a common, benign growth of skin cells. It typically appears as a brown, flat or raised spot, often with a ‘stuck-on’ appearance.

They are characterized by a rope-like pattern of cells, also known as 'string sign'.

They are benign proliferations of melanocytes, which are the cells that produce pigment.

A precancerous skin lesion often caused by prolonged sun exposure. About 10% may progress to squamous cell carcinoma if untreated.

A type of skin cancer arising from the squamous cells of the epidermis. It's often found in sun-damaged areas, scars, or sites with chronic infection. SCC is more likely to spread (metastasize) than BCC.

A type of skin cancer that originates in the squamous cells of the epidermis but hasn't yet invaded deeper tissue.

This type of SCC has spread beyond the epidermis and into the dermis or subcutis. It's characterized by abnormal keratinocytes invading deeper layers.

UVB radiation is strongly linked to sunburn, while UVA radiation contributes to tanning and premature aging.

UVB radiation can directly damage DNA within keratinocytes, which are skin cells, increasing the risk of skin cancer.

Exposure to UV light is the most common trigger for SCC development.

SCC is more likely to develop in individuals with weakened immune systems, such as transplant recipients, and those with genetic disorders like xeroderma pigmentosum.