Surgery, if feasible, is the only curative therapy. If the tumor has metastasized (most commonly, to the liver) and is considered incurable, there are some promising treatment modalities, such as radiolabeled octreotide (e.g. Lutetium (Lu) DOTA-octreotate) or the radiopharmaceutical 131I-mIBG (meta iodo benzyl guanidine) for arresting the growth of the tumors and prolonging survival in patients with liver metastases, though these are currently experimental.

Chemotherapy is of little benefit and is generally not indicated. Octreotide or Lanreotide (somatostatin analogues) may decrease the secretory activity of the carcinoid, and may also have an anti-proliferative effect. Interferon treatment is also effective, and usually combined with somatostatin analogues.

As the metastatic potential of a coincidental carcinoid is probably low, the current recommendation is for follow up in 3 months with CT or MRI, labs for tumor markers such as serotonin, and a history and physical, with annual physicals thereafter.

This is considered to be a hybrid between an exocrine and endocrine tumor derived from crypt cells of the appendix. Histologically, it forms clusters of goblet cells containing mucin with a minor admixture of Paneth cells and endocrine cells. The growth pattern is distinctive: typically producing a concentric band of tumor nests interspersed among the muscle and stroma of the appendiceal wall extending up the shaft of the appendix. This makes the lesion difficult to suspect grossly and difficult to measure. Small tumor nests may be camouflaged amongst the muscle or in periappendiceal fat; cytokeratin preparations best demonstrate the tumor cells; mucin stains are also helpful in identifying them. They behave in a more aggressive manner than do classical appendiceal carcinoids. Spread is usually to regional lymph nodes, peritoneum, and particularly the ovary. They do not produce sufficient hormonal substances to cause the carcinoid or other endocrine syndromes. In fact, they more closely resemble exocrine than endocrine tumors. The term 'crypt cell carcinoma' has been used for them, and though perhaps more accurate than considering them carcinoids, has not been a successful competitor.

Several issues help define appropriate treatment of a neuroendocrine tumor, including its location, invasiveness, hormone secretion, and metastasis. Treatments may be aimed at curing the disease or at relieving symptoms (palliation). Observation may be feasible for non-functioning low grade neuroendocrine tumors. If the tumor is locally advanced or has metastasized, but is nonetheless slowly growing, treatment that relieves symptoms may often be preferred over immediate challenging surgeries.

Intermediate and high grade tumors (noncarcinoids) are usually best treated by various early interventions (active therapy) rather than observation (wait-and-see approach).

Treatments have improved over the past several decades, and outcomes are improving. In malignant carcinoid tumors with carcinoid syndrome, the median survival has improved from two years to more than eight years.

Detailed guidelines for managing neuroendocrine tumors are available from ESMO, NCCN and a UK panel. The NCI has guidelines for several categories of NET: islet cell tumors of the pancreas, gastrointestinal carcinoids, Merkel cell tumors and pheochromocytoma/paraganglioma.

Even if the tumor has advanced and metastasized, making curative surgery infeasible, surgery often has a role in neuroendocrine cancers for palliation of symptoms and possibly increased lifespan.

Cholecystectomy is recommended if there is a consideration of long-term treatment with somatostatin analogs.

In general, treatment for PanNET encompasses the same array of options as other neuroendocrine tumors, as discussed in that main article. However, there are some specific differences, which are discussed here.

In functioning PanNETs, octreotide is usually recommended prior to biopsy or surgery but is generally avoided in insulinomas to avoid profound hypoglycemia.

PanNETs in MEN1 are often multiple, and thus require different treatment and surveillance strategies.

Some PanNETs are more responsive to chemotherapy than are gastroenteric carcinoid tumors. Several agents have shown activity. In well differentiated PanNETs, chemotherapy is generally reserved for when there are no other treatment options. Combinations of several medicines have been used, such as doxorubicin with streptozocin and fluorouracil (5-FU) and capecitabine with temozolomide. Although marginally effective in well-differentiated PETs, cisplatin with etoposide has some activity in poorly differentiated neuroendocrine cancers (PDNECs), particularly if the PDNEC has an extremely high Ki-67 score of over 50%.

Several targeted therapy agents have been approved in PanNETs by the FDA based on improved progression-free survival (PFS):

- everolimus (Afinitor) is labeled for treatment of progressive neuroendocrine tumors of pancreatic origin in patients with unresectable, locally advanced or metastatic disease. The safety and effectiveness of everolimus in carcinoid tumors have not been established.

- sunitinib (Sutent) is labeled for treatment of progressive, well-differentiated pancreatic neuroendocrine tumors in patients with unresectable locally advanced or metastatic disease. Sutent also has approval from the European Commission for the treatment of 'unresectable or metastatic, well-differentiated pancreatic neuroendocrine tumors with disease progression in adults'. A phase III study of sunitinib treatment in well differentiated pNET that had worsened within the past 12 months (either advanced or metastatic disease) showed that sunitinib treatment improved progression-free survival (11.4 months vs. 5.5 months), overall survival, and the objective response rate (9.3% vs. 0.0%) when compared with placebo.

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

The main treatment modalities are surgery, embolization and radiotherapy.

Surgery and radiation therapy have been the major treatments for medullary thyroid carcinoma.

A total thyroidectomy with bilateral neck dissection is the gold standard for treating medullary thyroid cancer, and is the most definitive means of achieving a cure in patients without distant metastases or extensive nodal involvement. Due to the extreme level of difficulty in successfully performing the neck dissection without extensive morbidity, it is very important for patients to seek care under an experienced surgeon at a Center of Excellence who operates on MTC patients at least several times a year. Risks of surgery include loss of vocal control, irreparable nerve damage, death or the need for second operation to clean out residual diseased lymph nodes left behind if the sentinel node biopsy was positive for cancerous spread. Extensive surgery can be effective when the condition is detected early, but a risk for recurrence remains, particularly in patients with multiple positive lymph nodes or extracapsular invasion. About half of patients have metastasis to regional lymph nodes at the time of diagnosis.

The European Society of Endocrine Surgeons has published recommendations for managing this condition in gene carriers. The timing of surgery depends on the type of mutation present. For those in the highest risk group, surgery is recommended in the first year of life. In lower risk cases surgery may be delayed up to the age of ten years, the precise timing depending on the mutation and other factors.

For symptomatic relief of carcinoid syndrome:

- Octreotide (a somatostatin analogue which decreases the secretion of serotonin by the tumor and, secondarily, decreases the breakdown product of serotonin (5-HIAA))

- Telotristat ethyl (Xermelo) along with a somatostatin analogue in patients not responding to somatostatin analogue monotherapy. It is a tryptophan hydroxylase inhibitor and reduces the production of serotonin.

- Peptide receptor radionuclide therapy (PRRT) with lutetium-177, yttrium-90 or indium-111 labeled to octreotate is highly effective

- Methysergide maleate (antiserotonin agent but not used because of the serious side effect of retroperitoneal fibrosis)

- Cyproheptadine (an antihistamine drug with antiserotonergic effects)

Alternative treatment for qualifying candidates:

- Surgical resection of tumor and chemotherapy (5-FU and doxorubicin)

- Endovascular, chemoembolization, targeted chemotherapy directly delivered to the liver through special catheters mixed with embolic beads (particles that block blood vessels), used for patients with liver metastases.

There is increased life-time risk of secondary cancers (relative risk 3.63), with a slightly increased mortality risk (1.21) according to a 2004 Swedish study of 481 patients.

The Stehlin Foundation currently offers DSRCT patients the opportunity to send samples of their tumors free of charge for testing. Research scientists are growing the samples on nude mice and testing various chemical agents to find which are most effective against the individual's tumor.

Patients with advanced DSRCT may qualify to participate in clinical trials that are researching new drugs to treat the disease.

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.

Disease progression is difficult to ascertain because the disease can metastasize anywhere in the body and can be too small to identify with any current technology. Markers of the condition such as chromogranin-A are imperfect indicators of disease progression.

The massive release of catecholamines in pheochromocytoma can cause damage to heart cells. This damage may be due to either compromising the coronary microcirculation or by direct toxic effects on the heart cells.

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.

Atypical pulmonary carcinoid tumour is a subtype of pulmonary carcinoid tumor. It is an uncommon low-grade malignant lung mass that is most often in the central airways of the lung. It is also known as "atypical lung carcinoid tumour", " atypical lung carcinoid" or "moderately differentiated neuroendocrine carcinoma".

It is a more aggressive than typical carcinoid tumors: nodal metastases in 70% vs. 5%. The 5 year survival is 49-69%.

Atypical carcinoid tumors have increased mitotic activity (2-10 per 10 HPF), nuclear pleomorphism or foci of necrosis.

The strumal carcinoid is a type of monodermal teratoma with histomorphologic features of (1) the thyroid gland and (2) a neuroendocrine tumour (carcinoid).

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.

Because of its rarity, there have been no randomized clinical trials of treatment of GCCL, and all information available derives from small retrospective institutional series or multicenter metadata.

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.

Pulmonary neuroendocrine tumors are neuroendocrine tumors localized to the lung: bronchus or pulmonary parenchyma.

Pulmonary neuroendocrine tumors include a spectrum of tumors from the low-grade typical pulmonary carcinoid tumor and intermediate-grade atypical pulmonary carcinoid tumor to the high-grade pulmonary large cell neuroendocrine carcinoma (LCNEC) and pulmonary small cell carcinoma (SCLC), with significant clinical, epidemiologic and genetic differences.

Treating PPB depends on the size and location of the tumor, whether the cancer has spread, and the child's overall health. Surgery is the main treatment for PPB. The main goal of surgery is to remove the tumor. If the tumor is too large to be completely removed, or if it's not possible to completely remove the tumor, surgery may be performed after chemotherapy. Because PPB can return after treatment, regular screening for possible recurrence should continue for 48 to 60 months, after diagnosis.

Pulmonary carcinoid tumour is a neuroendocrine tumour of the lung.

There are two types:

- Typical pulmonary carcinoid tumour

- Atypical pulmonary carcinoid tumour

A very large number of clinical trials have been conducted in "pure" SCLC over the past several decades. As a result, evidence-based sets of guidelines for treating monophasic SCLC are available. While the current set of SCLC treatment guidelines recommend that c-SCLC be treated in the same manner as "pure" SCLC, they also note that the evidence supporting their recommendation is quite weak. It is likely, then, that the optimum treatment for patients with c-SCLC remains unknown.

The current generally accepted standard of care for all forms of SCLC is concurrent chemotherapy (CT) and thoracic radiation therapy (TRT) in LD, and CT only in ED. For complete responders (patients in whom all evidence of disease disappears), prophylactic cranial irradiation (PCI) is also given. TRT serves to increase the probability of total eradication of residual locoregional disease, while PCI aims to eliminate any micrometastases to the brain.

Surgery is not often considered as a treatment option in SCLC (including c-SCLC) due to the high probability of distant metastases at the time of diagnosis. This paradigm was driven by early studies showing that the administration of systemic therapies resulted in improved survival as compared to patients undergoing surgical resection. Recent studies, however, have suggested that surgery for highly selected, very early-stage c-SCLC patients may indeed improve outcomes. Other experts recommend resection for residual masses of NSCLC components after complete local tumor response to chemotherapy and/or radiotherapy in c-SCLC.

Although other combinations of drugs have occasionally been shown to be noninferior at various endpoints and in some subgroups of patients, the combination of cisplatin or carboplatin plus etoposide or irinotecan are considered comparable first-line regimens for SCLC. For patients who do not respond to first line therapy, or who relapse after complete remission, topotecan is the only agent which has been definitively shown to offer increased survival over best supportive care (BSC), although in Japan amirubicin is considered effective as salvage therapy.

Importantly, c-SCLC is usually much more resistant to CT and RT than "pure" SCLC. While the mechanisms for this increased resistance of c-SCLC to conventional cytotoxic treatments highly active in "pure" SCLC remain mostly unknown, recent studies suggest that the earlier in its biological history that a c-SCLC is treated, the more likely it is to resemble "pure" SCLC in its response to CT and RT.