Squamous Cell Carcnoma Higher Risk Factors

Non melanoma skin cancer ---> squamous cell carcinoma ---> metastatic risk

These include the following factors:
Recurrent tumor

Anatomic location
High risk: central face, eyelid, eyebrow, periorbital, nose, lip, chin, mandible, temple, ear, in front or behind the ear, genitalia, hand and foot
Medium risk: cheeks, forehead, scalp, and neck
Low risk: trunk, extremity (excluding hand/foot)

Size
Lesions +6 mm on high-risk area
Lesions +10 mm on medium-risk area
Lesions +20 mm on low-risk area

Histology
Poorly differentiated

Depth of invasion
Clark's level IV (lesion that involves the reticular dermis), V (lesion that invades into subcutaneous fat), or +4 mm

Perineural invasion

Rapid growth

Etiology
Scar, chronic ulcer or inflammatory process, sinus tract, sites of prior radiation therapy

Immunosupression

Basal Cell Carcnoma Higher Risk Factors

Non melanoma skin cancer ---> Basal cell carcinoma ---> metastatic risk

These include the following factors:
Recurrent tumor

Anatomic location
High risk: central face, eyelid, eyebrow, periorbital, nose, lip, chin, mandible, temple, ear, in front or behind the ear, genitalia, hand and foot
Medium risk: cheeks, forehead, scalp, and neck
Low risk: trunk, extremity (excluding hand/foot)

Size
Lesions +6 mm on high-risk area
Lesions +10 mm on medium-risk area
Lesions +20 mm on low-risk area

Histologic subtype pattern
Aggressive growth (morpheaform, fibrosing, sclerosing, infiltrating)
Micronodular

Ill-defined clinical borders
Perineural invasion
Development in sites of prior radiation
Immunosuppression