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.

Carcinoid Syndrome is multiple in 1/5 cases.

Incidence of Gastric Carcinoid is increased in Achlorhydria,Hashimoto's thyroiditis,Pernicious anemia.

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.

The prognosis for DSRCT remains poor. Prognosis depends upon the stage of the cancer. Because the disease can be misdiagnosed or remain undetected, tumors frequently grow large within the abdomen and metastasize or seed to other parts of the body.

There is no known organ or area of origin. DSRCT can metastasize through lymph nodes or the blood stream. Sites of metastasis include the spleen, diaphragm, liver, large and small intestine, lungs, central nervous system, bones, uterus, bladder, genitals, abdominal cavity, and the brain.

A multi-modality approach of high-dose chemotherapy, aggressive surgical resection, radiation, and stem cell rescue improves survival for some patients. Reports have indicated that patients will initially respond to first line chemotherapy and treatment but that relapse is common.

Some patients in remission or with inoperable tumor seem to benefit from long term low dose chemotherapy, turning DSRCT into a chronic disease.

Carcinoid (also carcinoid tumor) is a slow-growing type of neuroendocrine tumor originating in the cells of the neuroendocrine system. In some cases, metastasis may occur. Carcinoid tumors of the midgut (jejunum, ileum, appendix, and cecum) are associated with carcinoid syndrome.

Carcinoid tumors are the most common malignant tumor of the appendix, but they are most commonly associated with the small intestine, and they can also be found in the rectum and stomach. They are known to grow in the liver, but this finding is usually a manifestation of metastatic disease from a primary carcinoid occurring elsewhere in the body. They have a very slow growth rate compared to most malignant tumors. The median age at diagnosis for all patients with neuroendocrine tumors is 63 years.

Genetic changes are very high in SCLC and LCNEC, but usually low for TC, intermediate for AC.

A number of PPBs have shown trisomy 8 (17 out of 23 cases studied per the PPB registry). Trisomy 2 and p53 mutations/deletions have also been described.

An association with mutations in the DICER1 gene has been reported. Mutations in this gene are found in 2/3 cases.

There are no known risk factors that have been identified specific to the disease. The tumor appears to arise from the primitive cells of childhood, and is considered a childhood cancer.

Research has indicated that there is a chimeric relationship between desmoplastic small-round-cell tumor (DSRCT) and Wilms' tumor and Ewing's sarcoma. Together with neuroblastoma and non-Hodgkin's lymphoma, they form the small cell tumors.

DSRCT is associated with a unique chromosomal translocation t(11;22)(p13:q12) resulting in an EWS/WT1 transcript that is diagnostic of this tumor. This transcript codes for a protein that acts as a transcriptional activator that fails to suppress tumor growth.

The EWS/WT1 translocation product targets ENT4. ENT4 is also known as PMAT.

Current consensus is that the long-term prognosis of c-SCLC patients is determined by the SCLC component of their tumor, given that "pure" SCLC seems to have the worst long-term prognosis of all forms of lung cancer. Although data on c-SCLC is very sparse, some studies suggest that survival rates in c-SCLC may be even worse than that of pure SCLC, likely due to the lower rate of complete response to chemoradiation in c-SCLC, although not all studies have shown a significant difference in survival.

Untreated "pure" SCLC patients have a median survival time of between 4 weeks and 4 months, depending on stage and performance status at the time of diagnosis.

Given proper multimodality treatment, SCLC patients with limited disease have median survival rates of between 16 and 24 months, and about 20% will be cured. In patients with extensive disease SCLC, although 60% to 70% will have good-to-complete responses to treatment, very few will be cured, with a median survival of only 6 to 10 months.

Some evidence suggests that c-SCLC patients who continue to smoke may have much worse outcomes after treatment than those who quit.

Reliable comprehensive incidence statistics for c-SCLC are unavailable. In the literature, the frequency with which the c-SCLC variant is diagnosed largely depends on the size of tumor samples, tending to be higher in series where large surgical resection specimens are examined, and lower when diagnoses are based on small cytology and/or biopsy samples. Tatematsu "et al." reported 15 cases of c-SCLC (12%) in their series of 122 consecutive SCLC patients, but only 20 resection specimens were examined. In contrast, Nicholson "et al." found 28 c-SCLC (28%) in a series of 100 consecutive resected SCLC cases. It appears likely, then, that the c-SCLC variant comprises 25% to 30% of all SCLC cases.

As the incidence of SCLC has declined somewhat in the U.S. in recent decades, it is likely that c-SCLC has also decreased in incidence. Nevertheless, small cell carcinomas (including the c-SCLC variant) still comprise 15–20% of all lung cancers, with c-SCLC probably accounting for 4–6%. With 220,000 cases of newly diagnosed lung cancer in the U.S. each year, it can be estimated that between 8,800 and 13,200 of these are c-SCLC.

In a study of 408 consecutive patients with SCLC, Quoix and colleagues found that presentation as a solitary pulmonary nodule (SPN) is particularly indicative of a c-SCLC — about 2/3 of their SPN's were pathologically confirmed to be c-SCLC's containing a large cell carcinoma component.

The prognosis of patients with FA as a whole is considered to be better than that of most other forms of non-small cell carcinoma, including biphasic pulmonary blastoma.

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.

Pancreatic neuroendocrine tumors (PanNETs, PETs, or PNETs), often referred to as "islet cell tumors", or "pancreatic endocrine tumors" are neuroendocrine neoplasms that arise from cells of the endocrine (hormonal) and nervous system within the pancreas.

PanNETs are a type of neuroendocrine tumor, representing about one third of gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Many PanNETs are benign, while some are malignant. Aggressive PanNET tumors have traditionally been termed "islet cell carcinoma".

PanNETs are quite distinct from the usual form of pancreatic cancer, the majority of which are adenocarcinomas, which arises in the exocrine pancreas. Only 1 or 2% of clinically significant pancreas neoplasms are PanNETs.

GCCs have an aggressive course compared to other appendiceal neuroendocrine tumours.

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.

The goblet cell carcinoid, abbreviated GCC and also known as crypt cell carcinoma and neuroendocrine tumour with goblet cell differentiation, is a rare biphasic gastrointestinal tract tumour that consists of a neuroendocrine component and a conventional carcinoma, histologically arising from Paneth cells.

PanNETs are sometimes abbreviated as PETs or PNETs: such use should not to be confused with the primitive neuroectodermal tumor (PNET).

The majority of PanNETs are benign, while some are malignant. The World Health Organization (WHO) classification scheme places neuroendocrine tumors into three main categories, which emphasize the tumor grade rather than the anatomical origin. In practice, those tumors termed well or intermediately differentiated PanNETs in the WHO scheme are sometimes called "islet cell tumors." The high grade subtype, termed neuroendocrine cancer (NEC) in the WHO scheme, is synonymous with "islet cell carcinoma".

FA is a rare tumor, with a relative incidence estimated to be no more than 0.5% of all lung cancers.

FA is exceptionally rare in children, with only a handful of cases reported to date, However, several case reports have involved FA's in pregnant women or the early postnatal period.

Although estimates vary, the annual incidence of clinically significant neuroendocrine tumors is approximately 2.5–5 per 100,000; two thirds are carcinoid tumors and one third are other NETs.

The prevalence has been estimated as 35 per 100,000, and may be considerably higher if clinically silent tumors are included. An autopsy study of the pancreas in people who died from unrelated causes discovered a remarkably high incidence of tiny asymptomatic NETs. Routine microscopic study of three random sections of the pancreas found NETs in 1.6%, and multiple sections identified NETs in 10%. As diagnostic imaging increases in sensitivity, such as endoscopic ultrasonography, very small, clinically insignificant NETs may be coincidentally discovered; being unrelated to symptoms, such neoplasms may not require surgical excision.

Pleuropulmonary blastoma (PPB) is a rare cancer originating in the lung or pleural cavity. It occurs most often in infants and young children but also has been reported in adults. In a retrospective review of 204 children with lung tumors, pleuropulmonary blastoma and carcinoid tumor were the most common primary tumors (83% of the 204 children had secondary tumors spread from cancers elsewhere in the body). Pleuropulmonary blastoma is regarded as malignant. The male:female ratio is approximately one.

Most individuals come to clinical attention during the 5th decade, although the age range is broad (20 to 80 years). There is an equal gender distribution.

Surgical excision is the preferred method of treatment for benign glomus tumors.

Roughly 10–35% of NSCLC patients will have drug sensitizing mutations of the "EGFR." The distribution of these mutations have been found to be race-dependent, with one study estimating that 10% of Caucasians but 50% of Asians will be found to have such tumor markers. A number of different EGFR mutations have been discovered, however certain aberrations will result in hyperactive forms of the protein. Patients with these mutations are more likely to have adenocarcinoma histology and be non-smokers or light smokers. These patients have been shown to be sensitized to certain medications which block the EGFR protein known as tyrosine kinase inhibitors specifically, erlotinib, gefitinib or afatinib.

Reliable identification of mutations in lung cancer needs careful consideration due to the variable sensitivity of diagnostic techniques

Paragangliomas originate from paraganglia in chromaffin-negative glomus cells derived from the embryonic neural crest, functioning as part of the sympathetic nervous system (a branch of the autonomic nervous system). These cells normally act as special chemoreceptors located along blood vessels, particularly in the carotid bodies (at the bifurcation of the common carotid artery in the neck) and in aortic bodies (near the aortic arch).

Accordingly, paragangliomas are categorised as originating from a neural cell line in the World Health Organization classification of neuroendocrine tumors. In the categorization proposed by Wick, paragangliomas belong to group II. Given the fact that they originate from cells of the orthosympathetic system, paragangliomas are closely related to pheochromocytomas, which however are chromaffin-positive.

"Lung tumors" are neoplastic tumors of the lung These include:

Primary tumors of the lung/pulmonary system:

- Bronchial leiomyoma, a rare, benign tumor

- Lung cancer, the term commonly used to refer to "carcinoma of the lung"

- Pulmonary carcinoid tumor

- Pleuropulmonary blastoma

- Neuroendocrine tumors of the lung

- Lymphomas of the lung.

- Sarcomas of the lung.

- Some rare vascular tumors of the lung

Non-lung tumors which may grow into the lungs:

- Mediastinal tumors

- Pleural tumors

Metastasis or secondary tumors/neoplasms with other origin:

- Metastasis to the lung