1. Squamous cell carcinoma, referred to as squamous cell carcinoma, often occurs in parts of the body covered by original squamous epithelium, such as skin, mouth, lips, cervix, vagina, esophagus, throat, penis, etc. It can also occur in other non-squamous epithelial covering parts with squamous metaplasia, such as bronchus, gallbladder and renal pelvis. Macroscopically, it often appears as a vegetable pattern, or it can form an ulcer-like shape due to necrosis and shedding, and the cancer tissue grows in deep infiltration at the same time. Microscopically, cancer cells are nested and have a clear boundary with stroma. In well-differentiated cancer nests of squamous cell carcinoma, intercellular bridges can be seen between cells, and layered keratin, called keratin beads or cancer beads, can appear in the center of cancer nests. Low-differentiated squamous cell carcinoma has no keratinized beads or even intercellular bridges, with obvious cell atypia and many mitotic images.
2. Basal cell carcinoma is caused by primitive epithelial buds or basal cells of epidermis, and it is more common in the face of the elderly, such as eyelids, cheeks and nose wings. Cancer nests are mainly composed of densely stained basal cell-like cancer cells. This kind of cancer grows slowly, often forms ulcers on the surface, and can penetrate and destroy deep tissues. But it hardly metastasizes, is very sensitive to radiotherapy and has a low clinical course of malignancy.
3. Transitional cell carcinoma comes from the transitional epithelium of bladder or renal pelvis, and painless hematuria often occurs in clinic. Tumors are often multiple, showing * or cauliflower shape, which can fester to form ulcer examination, large collection or extensive infiltration of deep tissues. Microscopically, cancer cells are like transitional epithelium, arranged in multiple layers and atypical. Generally, according to the cell atypia and infiltration, it is divided into grade I, II and III.
4. Adenocarcinoma is a malignant tumor originating from glands, ducts or secretory epithelium. According to its morphological structure and differentiation degree, it can be divided into tubular or *-shaped adenocarcinoma, solid carcinoma and mucinous carcinoma.
(1) Tubular or glandular adenocarcinoma: more common in stomach, intestine, thyroid, gallbladder, uterus and ovary. Cancer cells form gland structures with different sizes, shapes and irregular arrangements, that is, cancer nests. Cells are often arranged in multiple layers, with different nuclear sizes and mitotic images. When adenocarcinoma is accompanied by a large number of *-shaped structures, it is called *-shaped cancer; Adenocarcinoma with highly dilated glandular cavity and cystic shape is called cystadenocarcinoma; A cystadenocarcinoma that grows in a * shape is called a *-shaped cystadenocarcinoma.
(2) Solid cancer: poorly differentiated adenocarcinoma with high malignancy. Most of them occur in the breast, and a few can occur in the stomach and thyroid. The cancer nest is solid and has no glandular structure, with obvious dysplasia and many mitotic images. Some cancer nests are small and few, with many interstitial connective tissues and hard texture, which is called hard cancer. Other cancers have large nests, relatively few interstitial connective tissues, and can be accompanied by abundant lymphocyte infiltration, which is as soft as brain marrow, and is called medullary cancer.
(3) Myxoid carcinoma: common in stomach and large intestine. Visually, the cancer tissue is gray and translucent, like jelly, also known as glial cancer. Microscopically, due to the disintegration of the gland, mucus can accumulate in the gland cavity and form a mucus lake. When the mucus content in cancer tissue exceeds 50%, it is called mucinous adenocarcinoma. The other is the accumulation of mucus in cancer cells, which pushes the nucleus aside and makes the cells appear signet ring-like. This cell is called signet ring cell carcinoma. Signet-ring cell carcinoma can have extensive infiltration and metastasis in the early stage, and its prognosis is not good.