Body region (Figure 1)

Area H (In this zone, MMST is highly indicated)

- Central part of the face, eyelids, eyebrows, nose, lips, chin, ears, and the area around the ears.

- Genital region (perineal and perianal region).

- Warts/areolas, hands, feet, joints, and nails.

Area M

- Cheeks, forehead, occiput, neck, lower jaw.

- Pre-tibial region.

Area L

- Body and extremities (excluding the pretibial region, hands, feet, joints, and nails).

Patient

characteristics

Immunocompromised

HIV, transplanted organs

Genetic syndromes or disorders

Basal cell nevus syndrome, Xeroderma pigmentosum

Previously irradiated skin

The history of skin tumors

Characteristics of the tumor

The presence of tumor tissue at the margins in the previous excision of the tumor lesion

Positive margins in the previous excision

Aggressive features of a tumor

BCC: Aggressive histological subtype, perineural spread of the tumor

PCC: Poorly differentiated tumor (high degree of nuclear polymorphism, high mitotic index, or low degree of keratinization), perineural or perivascular spread of the tumor