<unk> s<unk> n be definitively diagnosed through biopsy, including fine-needle aspiration (FNA), core biopsy, or subtotal removal of single node,. Microscopic examination by a pathologist is then necessary to identify molecular, cellular, or tissue architectural characteristics of epithelial cells. Types *Oral: Most oral<unk> ncers are squamous-cell<unk>  *Lung:<unk>  comprises >98% of all lung<unk> ncers. *Breast: Nearly all breast<unk> ncers are ductal<unk> . *Prostate: The most common form of<unk>  of the prostate is adenocarcinoma. *Colon and rectum: Nearly all malignancies of the colon and rectum are either adenocarcinoma or squamous cell<unk> . *Pancreas: Pancreatic<unk>  is almost always of the adenocarcinoma type and is highly lethal. *Ovaries: One of the most deadly forms due to late detection. Some<unk> s are named for their or the putative cell of origin, (e.g.hepatocellular<unk> , renal cell<unk> . Staging Staging of<unk>  refers to the process of combining physical/clinical examination, pathological review of cells and tissues, surgical techniques, laboratory tests, and imaging studies in a logical fashion to obtain information about the size of the neoplasm and the extent of its invasion and metastasis.<unk> s are usually staged with Roman numerals. In most classifications, Stage I and Stage II<unk> s are confirmed when the tumor has been found to be small and/or to have spread to local structures only. Stage III<unk> s typically have been found to have spread to regional lymph nodes, tissues, and/or organ structures, while Stage IV tumors have already metastasized through the blood to distant sites, tissues, or organs. In some types of<unk> s, Stage 0<unk>  has been used to describe<unk>  in situ, and occult<unk> s detectable only via examination of sputum for malignant cells (in lung<unk> s). In more recent staging systems, substages (a, b, c) are becoming more commonly used to better define groups of patients with similar prognosis or treatment options.<unk>  stage is the variable that has been most consistently and tightly linked to the prognosis of the malignancy. The criteria for staging<unk> n differ dramatically based upon the organ system in which the tumor arises. For example, the colon and bladder<unk> ncer staging system relies on depth of invasion, staging of breast<unk>  is more dependent on the size of the tumor, and in renal<unk> , staging is based on both the size of the tumor and the depth of the tumor invasion into the renal sinus.<unk>  of the lung has a more complicated staging system, taking into account a number of size and anatomic variables. The UICC/AJCC TNM systems are most often used. For some common tumors, however, classical staging methods (such as the Dukes classification for colon<unk> ncer) are still used. Grading Grading of<unk> s refers to the employment of criteria intended to semi-quantify the degree of cellular and tissue maturity seen in the transformed cells relative to the appearance of the normal parent epithelial tissue from which the<unk>  derives. Grading of<unk>  is most often done after a treating physician and/or surgeon obtains a sample of suspected tumor tissue using surgical resection, needle or surgical biopsy, direct washing or brushing of tumor tissue, sputum cytopathology, etc. A pathologist then examines the tumor and its stroma, perhaps utilizing staining, immunohistochemistry, flow cytometry, or other methods. Finally, the pathologist classifies the tumor semi-quantitatively into one of three or four grades, including: *Grade 1, or well differentiated: there is a close, or very close, resemblance to the normal parent tissue, and the tumor cells are easily identified and classified as a particular malignant histological entity; *Grade 2, or moderately differentiated: there is considerable resemblance to the parent cells and tissues, but abnormalities<unk> n commonly be seen and the more complex features are not particularly well-formed; *Grade 3, or poorly differentiated: there is very little resemblance between the malignant tissue and the normal parent tissue, abnormalities are evident, and the more complex architectural features are usually rudimentary or primitive; *Grade 4, or undifferentiated<unk> : these<unk> s bear no significant resemblance to the corresponding parent cells and tissues, with no visible formation of glands, ducts, bridges, stratified layers, keratin pearls, or other notable characteristics consistent with a more highly differentiated neoplasm. Although there is definite and convincing statistical correlation between<unk>  grade and tumor prognosis for some tumor types and sites of origin, the strength of this association<unk> n be highly variable. It may be stated generally, however, that the higher the grade of the lesion, the worse is its prognosis.
Carcinoma
Papilloma
Papillomatosis
Acinic cell carcinoma
Carcinosis
Condyloma
Colorectal adenoma
Calcinosis