As of 2004, no simple and comprehensive classification system has been devised and<unk> cepted within the scientific community. Traditionally, however, malignancies have generally been classified into various types using a combination of criteria, including: The cell type from which they start; specifically: * Epithelial cells ⇨<unk>  * Non-hematopoietic mesenchymal cells ⇨ sarcoma * Hematopoietic cells *Bone marrow-derived cells that normally mature in the bloodstream ⇨ leukemia * Bone marrow-derived cells that normally mature in the lymphatic system ⇨ lymphoma * Germ cells ⇨ germinoma Other criteria that play a role include: * The degree to which the malignant cells resemble their normal, untransformed counterparts * The appearance of the local tissue and stromal architecture * The anatomical location from which tumors arise * Genetic, epigenetic, and molecular features Histological types ; Adenocarcinoma: (adeno = gland) Refers to a<unk>  featuring microscopic glandular-related tissue cytology, tissue architecture, and/or gland-related molecular products, e.g., mucin. ; Squamous cell<unk> : Refers to a<unk>  with observable features and characteristics indicative of squamous differentiation (intercellular bridges, keratinization, squamous pearls). ; Adenosquamous<unk> : Refers to a mixed tumor containing both adenocarcinoma and squamous cell<unk> , wherein each of these cell types comprise at least 10% of the tumor volume. ; Anaplastic<unk> : Refers to a heterogeneous group of high-grade<unk> s that feature cells lacking distinct histological or cytological evidence of any of the more specifically differentiated neoplasms. These tumors are referred to as anaplastic or undifferentiated<unk> s. ; Large cell<unk> : Composed of large, monotonous rounded or overtly polygonal-shaped cells with abundant cytoplasm. ; Small cell<unk> : Cells are usually round and are less than approximately 3 times the diameter of a resting lymphocyte and with little evident cytoplasm. Occasionally, small cell malignancies may themselves have significant components of slightly polygonal and/or spindle-shaped cells. There are a large number of rare subtypes of anaplastic, undifferentiated<unk> . Some of the more well known include the lesions containing pseudo-sarcomatous components: spindle cell<unk>  (containing elongated cells resembling connective tissue<unk> ncers), giant cell<unk>  (containing huge, bizarre, multinucleated cells), and sarcomatoid<unk>  (mixtures of spindle and giant cell<unk> . Pleomorphic<unk>  contains spindle cell and/or giant cell components, plus at least a 10% component of cells characteristic of more highly differentiated types (i.e. adenocarcinoma and/or squamous cell<unk> . Very rarely, tumors may contain individual components resembling both<unk>  and true sarcoma, including<unk> rcoma and pulmonary blastoma. A history of cigarette smoking is the most common<unk> use of large cell<unk> .<unk>  of unknown primary site The term<unk>  has also come to encompass malignant tumors composed of transformed cells whose origin or developmental lineage is unknown (see<unk> ncer of unknown primary origin; CUP), but that possess certain specific molecular, cellular, and histological characteristics typical of epithelial cells. This may include the production of one or more forms of cytokeratin or other intermediate filaments, intercellular bridge structures, keratin pearls, and/or tissue architectural motifs such as stratification or pseudo-stratification. ICD-10 code * (8010-8045) Epithelial neoplasms, NOS * (8050-8080) Squamous cell neoplasms * () Squamous cell<unk> , NOS * (8090-8110) Basal cell neoplasms * () Basal cell<unk> , NOS * (8120-8130) Transitional cell<unk> s * (8140-8380) Adenocarcinomas * () Adenocarcinoma, NOS * () Linitis plastica * () Vipoma * () Cholangiocarcinoma * () Hepatocellular<unk> , NOS * () Adenoid cystic<unk>  * () Renal cell<unk>  * () Grawitz tumor * (8390-8420) Adnexal and Skin appendage Neoplasms * (8430-8439) Mucoepidermoid Neoplasms * (8440-8490) Cystic, Mucinous and Serous Neoplasms * (8500-8540) Ductal, Lobular and Medullary Neoplasms * (8550-8559)<unk> inar cell neoplasms * (8560-8580) Complex epithelial neoplasms<unk>  In situ The term<unk>  in situ (or CIS) is a term for cells that are significantly abnormal but not<unk> ncer. They are thus not typically<unk> s.
Carcinoma
Papilloma
Papillomatosis
Acinic cell carcinoma
Carcinosis
Condyloma
Colorectal adenoma
Calcinosis