Pagetoid is a term used in dermatology to refer to "upward spreading" of melanocyte

Melanocyte

-External links: - "Eye: fovea, RPE" - "Integument: pigmented skin"...

s into the epidermis. 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 carcinoma

Squamous cell carcinoma , occasionally rendered as "squamous-cell carcinoma", is a histologically distinct form of cancer. It arises from the uncontrolled multiplication of malignant cells deriving from epithelium, or showing particular cytological or tissue architectural characteristics of...

, melanoma

Melanoma

Melanoma is a malignant tumor of melanocytes. Melanocytes are cells that produce the dark pigment, melanin, which is responsible for the color of skin. They predominantly occur in skin, but are also found in other parts of the body, including the bowel and the eye...

 in situ

In situ

In situ is a Latin phrase which translated literally as 'In position'. It is used in many different contexts.-Aerospace:In the aerospace industry, equipment on board aircraft must be tested in situ, or in place, to confirm everything functions properly as a system. Individually, each piece may...

, Pagetoid Bowen disease and other carcinoma

Carcinoma

Carcinoma is the medical term for the most common type of cancer occurring in humans. Put simply, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that generally arises from cells originating in the endodermal or ectodermal germ layer during...

s can all display pagetoid growth.