While cancer is generally considered a disease of old age, children can also develop cancer. In contrast to adults, carcinomas are exceptionally rare in children..

The two biggest risk factors for ovarian carcinoma are age and family history.

This form of cancer is often seen in those who chew tobacco or use snuff orally, so much so that it is sometimes referred to as "Snuff dipper's cancer." Chewing betel nuts is an additional risk factor commonly seen in Taiwan.

EMECL is extremely rare, with only a handful of cases reported in the literature.

In the lung, two salivary gland-like carcinomas, mucoepidermoid carcinoma and adenoid cystic carcinoma, while extremely uncommon, occur far more often than does EMECL.

A Clear-cell carcinoma is a carcinoma (i.e. not a sarcoma) showing clear cells.

"A rare type of tumor, usually of the female genital tract, in which the insides of the cells look clear when viewed under a microscope. Also called clear cell adenocarcinoma and mesonephroma."

Examples :

- Clear cell renal cell carcinoma ~ clear cell kidney cancer

- Uterine clear-cell carcinoma ~ clear cell endometrial cancer

- Clear-cell ovarian carcinoma

The prognosis of EMECL is relatively good, and considerably better than most other forms of NSCLC. The skull and dura are possible sites for metastasis from pulmonary EMC. The MIB-1 index is a predictive marker of malignant potential.

LCIS (lobular neoplasia is considered pre-cancerous) is an indicator (marker) identifying women with an increased risk of developing invasive breast cancer. This risk extends more than 20 years. Most of the risk relates to subsequent invasive ductal carcinoma rather than to invasive lobular carcinoma.

While older studies have shown that the increased risk is equal for both breasts, a more recent study suggests that the ipsilateral (same side) breast may be at greater risk.

In most series, LCLC's comprise between 5% and 10% of all lung cancers.

According to the Nurses' Health Study, the risk of large cell lung carcinoma increases with a previous history of tobacco smoking, with a previous smoking duration of 30 to 40 years giving a relative risk of approximately 2.3 compared to never-smokers, and a duration of more than 40 years giving a relative risk of approximately 3.6.

Another study concluded that cigarette smoking is the predominant cause of large cell lung cancer. It estimated that the odds ratio associated with smoking two or more packs/day for current smokers is 37.0 in men and 72.9 in women.

As of 2009, there have been approximately 120 reported cases of renal medullary carcinoma. In every instance except for one, the patients were positive for cell sickling. Wilms' tumor, the most common renal tumor of childhood, is responsible for 6-7% of childhood cancer whereas all remaining primary renal tumors (among which is included renal medullary carcinoma) collectively account for less than 1% of all childhood cancer and less than 10% of primary kidney tumors in childhood.

Clear-cell adenocarcinoma is a type of adenocarcinoma that shows clear cells.

Types include:

- Clear-cell adenocarcinoma of the vagina

- Clear-cell ovarian carcinoma

- Uterine clear-cell carcinoma

- Clear-cell adenocarcinoma of the lung (which is a type of Clear-cell carcinoma of the lung)

See also:

- Clear-cell squamous cell carcinoma of the lung

Prognosis and treatment is the same as for the most common type of ovarian cancer, which is epithelial ovarian cancer.

The median survival of primary peritoneal carcinomas is usually shorter by 2–6 months time when compared with serous ovarian cancer. Studies show median survival varies between 11.3–17.8 months. One study reported 19-40 month median survival (95% CI) with a 5-year survival of 26.5%.

Elevated albumin levels have been associated with a more favorable prognosis.

The true incidence, prevalence, and mortality of GCCL is generally unknown due to a lack of accurate cancer data on a national level. It is known to be a very rare tumor variant in all populations examined, however. In an American study of a database of over 60,000 lung cancers, GCCL comprised between 0.3% and 0.4% of primary pulmonary malignancies, with an age-adjusted incidence rate of about 3 new cases per million persons per year. With approximately 220,000 total lung cancers diagnosed in the US each year, the proportion suggests that approximately 660 and 880 new cases are diagnosed in Americans annually.

However, in a more recent series of 4,212 consecutive lung cancer cases, only one (0.024%) lesion was determined to be a "pure" giant-cell carcinoma after complete sectioning of all available tumor tissue. While some evidence suggests GCCL may have been considerably more common several decades ago, with one series identifying 3.4% of all lung carcinomas as giant-cell malignancies, it is possible that this number reflect

Most published case series and reports on giant cell-containing lung cancers show that they are diagnosed much more frequently in men than they are in women, with some studies showing extremely high male-to-female ratios (12:1 or more). In a study of over 150,000 lung cancer victims in the US, however, the gender ratio was just over 2:1, with women actually having a higher relative proportion of giant-cell cancers (0.4%) than men (0.3%).

Giant-cell carcinomas have been reported to be diagnosed in a significantly younger population than all non-small-cell carcinomas considered as a group. Like nearly all lung carcinomas, however, GCCs are exceedingly rare in very young people: in the US SEER program, only 2 cases were recorded to occur in persons younger than 30 years of age between 1983 and 1987. The average age at diagnosis of these tumors has been estimated at 60 years.

The vast majority of individuals with GCCL are heavy smokers.

Although the definitions of "central" and "peripheral" can vary between studies, GCCL are consistently diagnosed much more frequently in the lung periphery. In a review of literature compiled by Kallenburg and co-workers, less than 30% of GCCLs arose in the hilum or other parts of the "central" pulmonary tree.

A significant predilection for genesis of GCCL in the upper lobes of victims has also been postulated.

Since the cancer most often presents at an advanced stage, prognosis is generally very poor, with median survival times of 3 months (range 1–7 months). Longer survival of beyond one year was reported in one patient and of up to eight years in one individual whose tumor was well circumscribed and non-metastatic at the time of diagnosis, suggesting that early detection could dramatically improve survival.

Giant-cell lung cancers have long been considered to be exceptionally aggressive malignancies that grow very rapidly and have a very poor prognosis.

Many small series have suggested that the prognosis of lung tumors with giant cells is worse than that of most other forms of non-small-cell lung cancer (NSCLC), including squamous cell carcinoma, and spindle cell carcinoma.

The overall five-year survival rate in GCCL varies between studies but is generally considered to be very low. The (US) Armed Forces Institute of Pathology has reported a figure of 10%, and in a study examining over 150,000 lung cancer cases, a figure of 11.8% was given. However, in the latter report the 11.8% figure was based on data that included spindle cell carcinoma, a variant which is generally considered to have a less dismal prognosis than GCCL. Therefore, the likely survival of "pure" GCCL is probably lower than the stated figure.

In the large 1995 database review by Travis and colleagues, giant-cell carcinoma has the third-worst prognosis among 18 histological forms of lung cancer. (Only small-cell carcinoma and large-cell carcinoma had shorter average survival.)

Most GCCL have already grown and invaded locally and/or regionally, and/or have already metastasized distantly, and are inoperable, at the time of diagnosis.

Transitional cell carcinoma of the ovary, abbreviated TCC of the ovary, is a rare type of ovarian cancer that has an appearance similar to urothelial carcinoma (also known as transitional cell carcinoma).

Verrucous carcinoma (VC) is an uncommon variant of squamous cell carcinoma. This form of cancer is often seen in those who chew tobacco or use snuff orally, so much so that it is sometimes referred to as "Snuff dipper's cancer."

Most patients with verrucous carcinoma have a good prognosis. Local recurrence is not uncommon, but metastasis to distant parts of the body is rare. Patients with oral verrucous carcinoma may be at greater risk of a second oral squamous cell carcinoma, for which the prognosis is worse.

Verrucous carcinoma may occur in various head and neck locations, as well as in the genitalia. The oral cavity is the most common site of this tumor. The ages range from 50 to 80 years with a male predominance and a median age of 67 years. VC may grow large in size, resulting in the destruction of adjacent tissue, such as bone and cartilage.

The diagnosis of VC is established by close communication between surgeons and pathologists.

Surgeons must provide adequate specimens including the full thickness of the tumors and adjacent uninvolved mucosa for correct diagnoses.

Surgery is considered as the treatment of choice, but the extent of surgical margin and the adjuvant radiotherapy are still controversial.

The major risk factors are cigarette smoking and alcohol consumption, while betel nut is an additional factor in Taiwan. Different gene mutation sites in head and neck cancer between western countries and Taiwan have been reported. The presentation of VC originated from exposure to different carcinogens may not be the same.

When associated with the lung, it is typically a centrally located large cell cancer (non-small cell lung cancer or NSCLC). It often has a paraneoplastic syndrome causing ectopic production of parathyroid hormone-related protein (PTHrP), resulting in hypercalcemia, however paraneoplastic syndrome is more commonly associated with small cell lung cancer.

It is primarily due to smoking.

LCC is, in effect, a "diagnosis of exclusion", in that the tumor cells lack light microscopic characteristics that would classify the neoplasm as a small-cell carcinoma, squamous-cell carcinoma, adenocarcinoma, or other more specific histologic type of lung cancer.

LCC is differentiated from small-cell lung carcinoma (SCLC) primarily by the larger size of the anaplastic cells, a higher cytoplasmic-to-nuclear size ratio, and a lack of "salt-and-pepper" chromatin.

15% of lung cancers in the US are of this type. Small cell lung cancer occurs almost exclusively in smokers; most commonly in heavy smokers and rarely in non-smokers.

Acinic cell carcinoma appears in all age groups, but presents at a younger median age (approx. 52 years) than most other salivary gland cancers. Occurrences in children are quite common.

Human papillomavirus infection (HPV) has been associated with SCC of the oropharynx, lung, fingers and anogenital region.

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").

Lymphoepithelioma-like carcinoma (LELC) is a medical term referring to a histological variant of malignant tumor arising from the uncontrolled mitosis of transformed cells originating in epithelial tissue (or in cells that display epithelial characteristics) that bear microscopic resemblance to lymphoepithelioma (nasopharyngeal carcinoma).

There is considerable variation in the classification of LELC—while it is perhaps most commonly considered a subtype of squamous cell carcinoma, it can also be classified as a form of large cell carcinoma (i.e. when occurring in the lung), and can be considered as a separate, unique entity.

In most anatomical sites, many cases are associated with the Epstein-Barr virus.

In the breast, the macroscopic, microscopic, epidemiologic, and prognostic features of LELC are very similar to "medullary carcinoma"; EBV status is one differentiator.

Basal-cell cancer is a very common skin cancer. It is much more common in fair-skinned individuals with a family history of basal-cell cancer and increases in incidence closer to the equator or at higher altitude. There are approximately 800,000 new cases yearly in the United States alone. Up to 30% of Caucasians develop basal-cell carcinomas in their lifetime. In Canada, the most common skin cancer is basal cell carcinoma (as much as one third of all cancer diagnoses), affecting 1 in 7 individuals over a lifetime.

In the United States approximately 3 out of 10 caucasians develop a basal cell carcinoma during their lifetime. This tumor accounts for approximately 70% of non-melanoma skin cancers. In 80 percent of all cases, basal cell carcinoma affects the skin of head and neck. Furthermore, there appears to be an increase in the incidence of basal-cell cancer of the trunk in recent years.

Most sporadic BCC arises in small numbers on sun-exposed skin of people over age 50, although younger people may also be affected. The development of multiple basal-cell cancer at an early age could be indicative of nevoid basal-cell carcinoma syndrome, also known as Gorlin's Syndrome.

Prognosis is good for acinic cell carcinoma of the parotid gland, with five-year survival rates approaching is 90%, and 20-year survival exceeding 50%. Patients with acinic cell carcinomas with high grade transformation (sometimes also called dedifferentiation) have significantly worse survival.

The prognosis of an acinic cell carcinoma originating in the lung is much more guarded than cases of this rare histotype occurring in most other organs, but is still considerably better than for other types of lung cancer.

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