Most bladder cancer is transitional cell, but bladder cancer associated with Schistosomiasis is often squamous cell carcinoma.

Spindle cell carcinoma is a type of cancer that begins in the skin or in tissues that line or cover internal organs and that contains long spindle-shaped cells. It is also called sarcomatoid carcinoma.

Vaginal squamous cell carcinoma spreads slowly and usually stays near the vagina, but may spread to the lungs and liver. This is the most common type of vaginal cancer.

Lung cancer is an extremely heterogeneous family of malignant neoplasms, with well over 50 different histological variants recognized under the 4th revision of the World Health Organization (WHO) typing system ("WHO-2004"), currently the most widely used lung cancer classification scheme. Because these variants have differing genetic, biological, and clinical properties, including response to treatment, correct classification of lung cancer cases are necessary to assure that lung cancer patients receive optimum management.

The WHO-2004 scheme groups lung carcinomas into 8 major types:

- Squamous cell carcinoma

- Small cell carcinoma

- Adenocarcinoma

- Large cell carcinoma

- Adenosquamous carcinoma

- Sarcomatoid carcinoma

- Carcinoid tumor

- Salivary gland-like carcinoma

EMECL is considered a subtype of salivary gland-like carcinoma, tumors so named because their histological appearance and characteristics closely resemble malignant neoplasms arising in the major and minor salivary glands.

Epithelial-myoepithelial carcinoma of the lung (EMECL) is a very rare histologic form of malignant epithelial neoplasm ("carcinoma") arising from lung tissue.

Lung cancer is a large and exceptionally heterogeneous family of malignancies. Over 50 different histological variants are explicitly recognized within the 2004 revision of the World Health Organization (WHO) typing system ("WHO-2004"), currently the most widely used lung cancer classification scheme. Many of these entities are rare, recently described, and poorly understood. However, since different forms of malignant tumors generally exhibit diverse genetic, biological, and clinical properties — including response to treatment — accurate classification of lung cancer cases are critical to assuring that patients with lung cancer receive optimum management.

Under WHO-2004, lung carcinomas are divided into 8 major taxa:

- Squamous cell carcinoma

- Small cell carcinoma

- Adenocarcinoma

- Large cell carcinoma

- Adenosquamous carcinoma

- Sarcomatoid carcinoma

- Carcinoid tumor

- Salivary gland-like carcinoma

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare subtype of renal cell carcinoma (RCC), that is included in the 2004 WHO classification of RCC. MTSCC is a rare neoplasm and is considered as a low-grade entity. It may be a variant of papillary RCC. This tumor occurs throughout life (age range 17–82 years) and is more frequent in females.

Invasive carcinoma of no special type (NST) is the most common form of invasive breast cancer. It accounts for 55% of breast cancer incidence upon diagnosis, according to statistics from the United States in 2004. On a mammogram, it is usually visualized as a mass with fine spikes radiating from the edges. On physical examination, this lump usually feels much harder or firmer than benign breast lesions such as fibroadenoma. On microscopic examination, the cancerous cells invade and replace the surrounding normal tissues. IDC is divided in several histological subtypes.

MTSCC has a gross appearance close to papillary RCC. Microscopically, it has three histologic components: mucin, tumor cells forming tubules, and spindle cells. It is characterized by the proliferation of cuboidal and spindle cells arranged in tubular or sheet-like arrays, typically with a mucinous or myxoid background.

In many cases, ductal carcinoma is asymptomatic, and detected as abnormal results on mammography. When symptoms occur, a painless, enlarging mass that does not fluctuate with the menstrual period may be felt. Pinching of the overlying skin may also be seen. Certain subtypes, such as inflammatory carcinomas, may result in a swollen, enlarged and tender breast. All variants of cancer, if there is metastatic spread, may cause enlarged lymph nodes and affect other organs.

Salivary gland–like carcinomas of the lung generally refers a class of rare cancers that arise from the uncontrolled cell division (mitosis) of mutated cancer stem cells in lung tissue. They take their name partly from the appearance of their abnormal cells, whose structure and features closely resemble those of cancers that form in the major salivary glands (parotid glands, submandibular glands and sublingual glands) of the head and neck. Carcinoma is a term for malignant neoplasms derived from cells of epithelial lineage, and/or that exhibit cytological or tissue architectural features characteristically found in epithelial cells.

This class of primary lung cancers contains several histological variants, including mucoepidermoid carcinoma of the lung, adenoid cystic carcinoma of the lung, epithelial-myoepithelial carcinoma of the lung, and other (even more rare) variants. .

Sarcomatoid carcinoma is a relatively uncommon form of cancer whose malignant cells have histological, cytological, or molecular properties of both epithelial tumors ("carcinoma") and mesenchymal tumors ("sarcoma").

Histological variants of lung cancer classified as sarcomatoid carcinoma include pleomorphic carcinoma, giant cell carcinoma, spindle cell carcinoma, carcinosarcoma, and pulmonary blastoma.

Lung cancers have been historically classified using two major paradigms. Histological classification systems group lung cancers according to the appearance of the cells and surrounding tissues when they are viewed under a microscope. Clinical classification systems divide lung cancers into groups based on medical criteria, particularly their response to different treatment regimens.

Before the mid-1900s, lung cancer was considered to be a single disease entity, with all forms treated similarly. In the 1960s, small cell lung carcinoma (SCLC) was recognized as a unique form of lung cancer, based both on its appearance (histology) and its clinical properties, including much greater susceptibility to chemotherapy and radiation, more rapid growth rate, and its propensity to metastasize widely early on in its course. Since then, most oncologists have based patient treatment decisions on a dichotomous division of lung cancers into SCLC and non-small cell lung carcinomas (NSCLC), with the former being treated primarily with chemoradiation, and the latter with surgery.

An explosion of new knowledge, accumulated mainly over the last 20 years, has proved that lung cancers should be considered an extremely heterogeneous family of neoplasms with widely varying genetic, biological, and clinical characteristics, particularly their responsiveness to the large number of newer treatment protocols. Well over 50 different histological variants are now recognized under the 2004 revision of the World Health Organization ("WHO-2004") typing system, currently the most widely used lung cancer classification scheme. Recent studies have shown beyond doubt that the old clinical classification paradigm of "SCLC vs. NSCLC" is now obsolete, and that correct "subclassification" of lung cancer cases is necessary to assure that lung cancer patients receive optimum management.

Approximately 98% of lung cancers are carcinoma, which are tumors composed of cells with epithelial characteristics. LCLC's are one of 8 major groups of lung carcinomas recognized in WHO-2004:

- Squamous cell carcinoma

- Small cell carcinoma

- Adenocarcinoma

- Large cell carcinoma

- Adenosquamous carcinoma

- Sarcomatoid carcinoma

- Carcinoid tumor

- Salivary gland-like carcinoma

Adenosquamous lung carcinoma (AdSqLC) is a biphasic malignant tumor arising from lung tissue that is composed of at least 10% by volume each of squamous cell carcinoma (SqCC) and adenocarcinoma (AdC) cells.

Giant-cell carcinoma of the lung (GCCL) is a rare histological form of large-cell lung carcinoma, a subtype of undifferentiated lung cancer, traditionally classified within the non-small-cell lung carcinomas (NSCLC).

The characteristic feature of this highly lethal malignancy is the distinctive light microscopic appearance of its extremely large cells, which are bizarre and highly pleomorphic, and which often contain more than one huge, misshapen, pleomorphic nucleus ("syncytia"), which result from cell fusion.

Although it is common in the lung cancer literature to refer to histologically mixed tumors containing significant numbers of malignant giant cells as "giant-cell carcinomas", technically a diagnosis of "giant-cell carcinoma" should be limited strictly to neoplasms containing "only" malignant giant cells (i.e. "pure" giant-cell carcinoma).

Aside from the great heterogeneity seen in lung cancers (especially those occurring among tobacco smokers), the considerable variability in diagnostic and sampling techniques used in medical practice, the high relative proportion of individuals with suspected GCCL who do not undergo complete surgical resection, and the near-universal lack of complete sectioning and pathological examination of resected tumor specimens prevent high levels of quantitative accuracy.

Like many malignancies, penile cancer can spread to other parts of the body. It is usually a primary malignancy, the initial place from which a cancer spreads in the body. Much less often it is a secondary malignancy, one in which the cancer has spread to the penis from elsewhere. The staging of penile cancer is determined by the extent of tumor invasion, nodal metastasis, and distant metastasis.

The T portion of the AJCC TNM staging guidelines are for the primary tumor as follows:

- TX: Primary tumor cannot be assessed.

- T0: No evidence of primary tumor.

- Tis: Carcinoma "in situ".

- Ta: Noninvasive verrucous carcinoma.

- T1a: Tumor invades subepithelial connective tissue without lymph vascular invasion and is not poorly differentiated (i.e., grade 3–4).

- T1b: Tumor invades subepithelial connective tissue with lymph vascular invasion or is poorly differentiated.

- T2: Tumor invades the corpus spongiosum or cavernosum.

- T3: Tumor invades the urethra or prostate.

- T4: Tumor invades other adjacent structures.

Anatomic Stage or Prognostic Groups of penile cancer are as follows:

- Stage 0—Carcinoma "in situ".

- Stage I—The cancer is moderately or well differentiated and only affects the subepithelial connective tissue.

- Stage II—The cancer is poorly differentiated, affects lymphatics, or invades the corpora or urethra.

- Stage IIIa—There is deep invasion into the penis and metastasis in one lymph node.

- Stage IIIb—There is deep invasion into the penis and metastasis into multiple inguinal lymph nodes.

- Stage IV—The cancer has invaded into structures adjacent to the penis, metastasized to pelvic nodes, or distant metastasis is present.

Around 95% of penile cancers are squamous cell carcinomas. They are classified into the following types:

- basaloid (4%)

- warty (6%)

- mixed warty-basaloid (17%)

- verrucous (8%)

- papillary (7%)

- other SCC mixed (7%)

- sarcomatoid carcinomas (1%)

- not otherwise specified (49%)

Other types of carcinomas are rare and may include small cell, Merkel cell, clear cell, sebaceous cell or basal cell tumors. Non-epithelial malignancies such as melanomas and sarcomas are even more rare.

Carcinoma is a type of cancer that develops from epithelial cells. Specifically, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that arises from cells originating in the endodermal, mesodermal and ectodermal germ layer during embryogenesis.

Carcinomas occur when the DNA of a cell is damaged or altered and the cell begins to grow uncontrollably and become malignant. It is from the Greek καρκίνωμα 'karkinoma' meaning sore, ulcer, or cancer, itself derived from "karkinos" 'crab'.

A urogenital neoplasm is a tumor of the urogenital system.

Types include:

- Cancer of the breast and female genital organs: (Breast cancer, Vulvar cancer, Vaginal cancer, Cervical cancer, Uterine cancer, Endometrial cancer, Ovarian cancer)

- Cancer of the male genital organs (Carcinoma of the penis, Prostate cancer, Testicular cancer)

- Cancer of the urinary organs (Renal cell carcinoma, Bladder cancer)

Bowen's disease typically presents as a gradually enlarging, well-demarcated red colored plaque with an irregular border and surface crusting or scaling. Bowen's disease may occur at any age in adults, but is rare before the age of 30 years; most patients are aged over 60. Any site may be affected, although involvement of palms or soles is uncommon. Bowen's disease occurs predominantly in women (70–85% of cases). About 60–85% of patients have lesions on the lower leg, usually in previously or presently sun-exposed areas of skin.

This is a persistent, progressive, unelevated, red, scaly or crusted plaque which is due to an intraepidermal carcinoma and is potentially malignant. The lesions may occur anywhere on the skin surface, including on mucosal surfaces. Freezing, cauterization, or diathermy coagulation is often effective treatment. Pathomorphologic study of tissue sampling revealed: polymorphism of spiny epithelial cells has progressed into atypism; increased mitosis; giant and multinucleate cells; acanthosis; hyperkeratosis and parakeratosis; basal membrane and basal layer are retained.

For several decades, primary lung cancers were consistently dichotomously classified for treatment and research purposes into small-cell lung carcinomas (SCLCs) and non-small-cell lung carcinomas (NSCLCs), based on an oversimplified approach that is now clearly outmoded. The new paradigm recognizes that lung cancers are a large and extremely heterogeneous family of malignant neoplasms, with over 50 different histological variants included in the 4th (2004) revision of the World Health Organization typing system, the most widely used lung cancer classification scheme ("WHO-2004"). These variants are increasingly appreciated as having different genetic, biological, and clinical properties, including prognoses and responses to treatment regimens, and therefore, that correct and consistent histological classification of lung cancers are necessary to validate and implement optimum management strategies.

About 1% of lung cancers are sarcomas, germ cell tumors, and hematopoietic tumors, while 99% of lung cancers are carcinoma. Carcinomas are tumors composed of transformed, abnormal cells with epithelial tissue architecture and/or molecular characteristics, and which derive from embryonic endoderm. Eight major taxa of lung carcinomas are recognized within the WHO-2004 classification:

1. Small-cell carcinoma

2. Squamous cell carcinoma

3. Adenocarcinoma

4. Large-cell carcinoma

5. Adenosquamous carcinoma

6. Sarcomatoid carcinoma

7. Carcinoid

8. Salivary gland-like carcinoma

The subclassification of GCCL among these major taxa has undergone significant changes in recent decades. Under the 2nd revision (1981) of the WHO classification, it was considered a subtype of large-cell carcinoma. In the 3rd (1999) revision, it was placed within a taxon called "Carcinomas with Pleomorphic, Sarcomatoid, or Sarcomatous Elements", along with pleomorphic carcinoma, spindle cell carcinoma, carcinosarcoma, and pulmonary blastoma, which are (arguably) related variants. While the 4th revision ("WHO-2004") retained the same grouping of lesions as the 3rd revision, the name of the major taxon was shortened to "sarcomatoid carcinomas".

The current rules for classifying lung cancers under WHO-2004, while useful and improved, remain to some extent fairly complex, ambiguous, arbitrary, and incomplete. Although it is fairly common for mixed tumors that are seen to contain malignant giant cells to be called "giant-cell carcinomas", "accurate" classification of a pulmonary tumor as a GCCL requires that the "entire tumor" consists "only" of malignant giant cells. Therefore, complete sampling of the entire tumor — obtained via a surgical resection — is absolutely necessary for a definitive diagnosis of GCCL to be made.

Bowen's disease, also known as squamous cell carcinoma" in situ" is a neoplastic skin disease. It can be considered as an early stage or intraepidermal form of squamous cell carcinoma. It was named after John T. Bowen.

Erythroplasia of Queyrat is a particular type of Bowen's disease that can arise on the glans or prepuce in males, and, on the vulva in females, and may be induced by human papilloma virus. It is reported to occur in the corneoscleral limbus.

Lung cancer is a large and exceptionally heterogeneous family of malignancies. Over 50 different histological variants are explicitly recognized within the 2004 revision of the World Health Organization (WHO) typing system ("WHO-2004"), currently the most widely used lung cancer classification scheme. Many of these entities are rare, recently described, and poorly understood. However, since different forms of malignant tumors generally exhibit diverse genetic, biological, and clinical properties — including response to treatment — accurate classification of lung cancer cases are critical to assuring that patients with lung cancer receive optimum management.

Approximately 99% of lung cancers are carcinoma, a term that indicates that the malignant neoplasm is composed of, or descended from, cells of epithelial lineage (i.e. derived from embryonic endoderm, as is the case in lung carcinomas, or from ectoderm), and/or that the malignant cells exhibit tissue architectural, cytological, or molecular features characteristically found in epithelial cells. Under WHO-2004, lung carcinomas are divided into 8 major taxa:

- Squamous cell carcinoma

- Small cell carcinoma

- Adenocarcinoma

- Large cell carcinoma

- Adenosquamous carcinoma

- Sarcomatoid carcinoma

- Carcinoid tumor

- Salivary gland-like carcinoma

SCLC is generally considered to be the most aggressive of these major forms of lung cancer, with the worst long term prognosis and survival rates. As a result, it is recommended that all multiphasic malignant lung tumors (i.e. those with more than one histological pattern) that are found to contain "any" proportion of SCLC cells should be classified as c-SCLC, and "not" as combined forms of any of the other histological variants present in the tumor. Currently, the only exception to this recommendation occurs in cases where anaplastic large cell lung carcinoma (LCLC) is the second histological component. In these instances, a minimum of 10% of the viable malignant cells present must be identified as LCLC before the tumor is considered to be a c-SCLC. Under the WHO-2004 classification scheme, c-SCLC is the only recognized variant of SCLC.

Combined small cell lung carcinoma (or c-SCLC, and rarely rendered as "small-cell lung carcinoma") is a form of multiphasic lung cancer that is diagnosed by a pathologist when a malignant tumor arising from transformed cells originating in lung tissue contains a component of small cell lung carcinoma (SCLC) admixed with one (or more) components of non-small cell lung carcinoma (NSCLC).