Pagetoid is a term used in dermatology to refer to "upward spreading" of abnormal cells in the epidermis (ie from bottom to top). It is uncommon and a possible indication of a precancerous or cancerous condition. Cells display pagetoid growth when they invade the upper epidermis from below.

Squamous cell carcinoma Squamous-cell carcinomas (SCCs), also known as epidermoid carcinomas, comprise a number of different types of cancer that begin in squamous cells. These cells form on the surface of the skin, on the lining of hollow organs in the body, and on the ...

melanoma 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 situ ''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...

, Pagetoid

Bowen's disease 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. ...

, ocular sebaceous carcinoma, and other

carcinoma Carcinoma is a malignancy that develops from epithelial cells. Specifically, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that arises from cells originating in the endodermal, mesodermal ...

s can all display pagetoid growth. The term ''pagetoid'' (i.e., 'Paget-like') is derived from the

extramammary Paget's disease 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 Pa ...

, wherein the large tumour cells are arranged singly or in small clusters within the epidermis and its appendages. These cells are distinguished by a clear halo from the surrounding epithelial cells and a finely granular cytoplasm. This proliferation of cells in the epidermis is responsible for the "buckshot scatter" pattern.{{cite web, url=http://www.dermnetnz.org/pathology/pathology-glossary.html, title=Dermatopathological terminology - DermNet New Zealand, website=www.dermnetnz.org This is a typical feature of superficial spreading type of

References

Dermatologic terminology Oncology