Squamous cell carcinoma is often transformed from keratosis, leukoplakia and other precancerous diseases. It grows faster and forms ulcers at an early stage. Some of them are nodular or cauliflower-like, which has less invasion on the deep movable basement; Some are butterfly-shaped, with obvious infiltration into the deep and strong destructiveness, often involving bones. Squamous cell carcinoma is often accompanied by purulent infection, odor and pain. Regional lymph node metastasis is more common. The patient's head is a huge squamous cell carcinoma, which is extremely smelly and has more purulent secretions and is easy to bleed. Cervical lymph node metastasis occurred. Squamous cell carcinoma at the junction of mucosa and skin develops fastest, and patients with mucosa are more likely to metastasize.

2. The onset of basal cell carcinoma is usually asymptomatic. At the beginning, it was mostly patchy papules with hard base, some of which were verrucous bulges, and then it broke into ulcer lesions with irregular, edge bulges, crater-like, uneven bottom and slow growth. Metastasis is rare. Superficial ulcers with translucent nodules at the edge first occur, and then gradually expand, which can erode the surrounding tissues and organs and become erosive ulcers. 3. Squamous cell carcinoma usually occurs in 30 ~ 50 years old, and basal cell carcinoma usually occurs in over 50 years old. The former has a rapid onset and often grows rapidly in a short period of time; The latter is slow. Squamous cell carcinoma usually occurs in the lower lip, tongue, nose and vulva, mostly at the junction of skin and mucosa. The edge of the ulcer is high, red and hard, ring-shaped and vegetable-shaped, with obvious peripheral inflammatory reaction and swollen lymph glands in many places. Basal cell carcinoma mainly occurs in orbit, canthus, nose, cheek, forehead and back of hand. The edge of the ulcer is waxy, nodular, rolled up, partially black, with little or no inflammatory reaction and little metastasis, mainly infiltrating into deep tissues.

Second, the clinical manifestations

1. Basal cell carcinoma is generally divided into four types, and the most common type is nodular ulcer. (1) Nodular ulcer type: At first, there were waxy nodules the size of a rice grain to a pea on the epidermis. Generally, the epidermis is quite hard, and there are often a few dilated capillaries on the surface, which are slightly higher than the skin surface, or no swelling like erythema, or slightly nodular, and the surface skin is slightly concave downward. Nodules can gradually expand or new lesions appear nearby, and merge with each other to form disc-shaped plaques with waxy luster. A brown, tan or dark gray scab often forms in the center, and then an ulcer appears under the scab, which gradually expands to form a round, oval or plastic ulcer, ranging in size from fingernails to copper coins. The edge of the ulcer is solid, rolled up, often translucent, skinny, and there is no inflammation around the skin. The bottom is pearly or waxy, and sometimes the damaged surface is complete. Ulcer slowly spread to the periphery and deep, like a mouse bite, forming a typical clinical form of basal cell carcinoma, called erosive ulcer. Ulcer can partially heal and scar, or spread to subcutaneous tissue, even cartilage and bones. All kinds of tissues can be destroyed into deep pits. Occurring on the face can destroy the cartilage and bone tissue of the nose, ears, orbit and maxillary sinus, causing bleeding or intracranial invasion or disfigurement. The damage of basal cell carcinoma develops slowly, with little regional lymph node metastasis and no metastasis to other places. (2) Pigmented type: Nodules are shallower than the plane, and the damage is the same as nodular ulcer type. Because it contains a lot of pigments, the damaged edges are dotted or reticulated dark brown or dark brown pigment spots besides pearl luster, and pigmentation can also be seen in the central part. After scab, scab is easy to bleed, and the scab can be dark brown or even carbon black particles, similar to malignant melanoma, which is easy to be misdiagnosed. (3) Sclerosing spot or fibrotic type: it occurs in the head and neck, and it is a hard yellowish or yellowish-white mottled block, slightly raised, with unclear boundary, like scleroderma, which can remain intact for a long time and finally fester. (4) Superficial type: The skin lesions are superficial, mostly occurring in the trunk, showing one or several pieces of infiltrating erythema, with desquamation or scabbing on the surface, and the edges or the whole skin lesions are slightly raised, and at least some edges are in the shape of small pearls or linear dikes. This type will eventually fibrosis. Similar to psoriasis, eczema or seborrheic dermatitis. 2. There is no obvious difference between the early clinical manifestations of squamous cell carcinoma and basal cell carcinoma. However, squamous cell carcinoma mostly occurs in long-term abnormal skin, which is often transformed from keratinization, mucosal leukoplakia or other precancerous diseases. The initial skin injury is usually a dry papule or a small nodule as big as millet to soybean. The surface is dark red or has telangiectasia, rough and uneven, and the center has closely attached keratin, which is not easy to fall off. Forced peeling is easy to cause bleeding, and the keratin will grow again after peeling. In the future, there may be an ulcer in the center, and the ulcer surface will continue to increase and develop faster than basal cell carcinoma. A cancerous ulcer with milky white particles or necrotic tissue is formed in a short time. Sometimes it will form a deep cave that looks like a volcanic vent. When complicated with infection, there is sticky pus, peculiar smell and conscious pain. Some squamous cell carcinoma develops outward and can attach to deep tissues, forming a vegetation with a wide base, which looks like a milky white or cauliflower tumor. The disease is developing rapidly and destructive. It can extend to connective tissue, cartilage, periosteum and bone, and regional lymph node metastasis can often occur, and visceral metastasis can occur in the later stage. Especially squamous cell carcinoma of mucosa is easy to metastasize.