As mentioned above, symptomatic features of paraneoplastic syndrome cultivate in four different ways: endocrine, neurological, mucocutaneous, and hematological. The most common presentation is a fever (release of endogenous pyrogens often related to lymphokines or tissue pyrogens), but the overall picture will often include several clinical cases observed which may specifically simulate more common benign conditions.

The following diseases manifest by means of mucocutaneous dysfunction: acanthosis nigricans, dermatomyositis, Leser-Trélat sign, necrolytic migratory erythema, Sweet's syndrome, Florid cutaneous papillomatosis, pyoderma gangrenosum, and acquired generalized hypertrichosis. Mucocutaneous dysfunctions of paraneoplastic syndromes can be seen in cases of itching (hypereosinophilia), immune system depression (latent varicella-zoster virus in sensory ganglia), pancreatic tumors (leading to adipose nodular necrosis of subcutaneous tissues, flushes (prostaglandin secretions), and even dermic melanosis (cannot be eliminated via urine and results in grey to black-blueish skin tones).

The first symptoms of neuroblastoma are often vague making diagnosis difficult. Fatigue, loss of appetite, fever, and joint pain are common. Symptoms depend on primary tumor locations and metastases if present:

- In the abdomen, a tumor may cause a swollen belly and constipation.

- A tumor in the chest may cause breathing problems.

- A tumor pressing on the spinal cord may cause weakness and thus an inability to stand, crawl, or walk.

- Bone lesions in the legs and hips may cause pain and limping.

- A tumor in the bones around the eyes or orbits may cause distinct bruising and swelling.

- Infiltration of the bone marrow may cause pallor from anemia.

Neuroblastoma often spreads to other parts of the body before any symptoms are apparent and 50 to 60% of all neuroblastoma cases present with metastases.

The most common location for neuroblastoma to originate (i.e., the primary tumor) is in the adrenal glands. This occurs in 40% of localized tumors and in 60% of cases of widespread disease. Neuroblastoma can also develop anywhere along the sympathetic nervous system chain from the neck to the pelvis. Frequencies in different locations include: neck (1%), chest (19%), abdomen (30% non-adrenal), or pelvis (1%). In rare cases, no primary tumor can be discerned.

Rare but characteristic presentations include transverse myelopathy (tumor spinal cord compression, 5% of cases), treatment-resistant diarrhea (tumor vasoactive intestinal peptide secretion, 4% of cases), Horner's syndrome (cervical tumor, 2.4% of cases), opsoclonus myoclonus syndrome and ataxia (suspected paraneoplastic cause, 1.3% of cases), and hypertension (catecholamine secretion or renal artery compression, 1.3% of cases).

Solitary fibrous tumor (SFT), also known as fibrous tumor of the pleura, is a rare mesenchymal tumor originating in the pleura or at virtually any site in the soft tissue including seminal vesicle. Approximately 78% to 88% of SFT's are benign and 12% to 22% are malignant.

Doege–Potter syndrome (DPS) is a paraneoplastic syndrome in which hypoglycemia is associated with solitary fibrous tumors. The hypoglycemia is the result of the tumors producing insulin-like growth factor 2. The syndrome was first described in 1930, by Karl Walter Doege (1867–1932), a German-American physician and by Roy Pilling Potter (1879–1968), an American radiologist, working independently; the full term "Doege–Potter syndrome" was infrequently used until the publication of a 2000 article using the eponym.

DPS is rare (as of 1976, less than one hundred cases were described), with a malignancy rate of 12–15%. Actual rates of hypoglycemia associated with a fibrous tumor are quite rare (a 1981 study of 360 solitary fibrous tumors of the lungs found that only 4% caused hypoglycemia), and are linked to large tumors with high rates of mitosis. Removal of the tumor will normally resolve the symptoms.

Tumors causing DPS tend to be quite large; in one case a , mass was removed, sufficiently large to cause a collapsed lung. In X-rays, they appear as a single mass with visible, defined borders, appearing at the edges of the lungs or a fissure dividing the lobes of the lungs. Similar hypoglycemic effects have been related to mesenchymal tumors.

About 80% of pleural SFTs originate in the visceral pleura, while 20% arise from parietal pleura. Although they are often very large tumors (up to 40 cm. in diameter), over half are asymptomatic at diagnosis. While some researchers have proposed that a SFT occupying at least 40% of the affected hemithorax be considered a "giant solitary fibrous tumor", no such "giant" variant has yet been recognized within the most widely used pleural tumor classification scheme.

Some SFTs are associated with the paraneoplastic Doege–Potter syndrome, which is caused by tumor production of IGF-2.

Hemangioblastomas (or haemangioblastomas, see spelling differences) (capilliary hemangioblastomas) are tumors of the central nervous system that originate from the vascular system usually during middle-age. Sometimes these tumors occur in other sites such as the spinal cord and retina. They may be associated with other diseases such as polycythemia (increased blood cell count), pancreatic cysts and Von Hippel-Lindau syndrome (VHL syndrome). Hemangioblastomas are most commonly composed of stromal cells in small blood vessels and usually occur in the cerebellum, brain stem or spinal cord. They are classed as grade one tumors under the World Health Organization's classification system.

The diagnosis is usually confirmed by a surgical pathologist, taking into account the clinical presentation, microscopic findings, and other laboratory tests. It may arise from any neural crest element of the sympathetic nervous system (SNS).

Esthesioneuroblastoma, also known as olfactory neuroblastoma, is believed to arise from the olfactory epithelium and its classification remains controversial. However, since it is not a sympathetic nervous system malignancy, esthesioneuroblastoma is a distinct clinical entity and is not to be confused with neuroblastoma.

Paraneoplastic cerebellar degeneration (PCD) is a paraneoplastic syndrome associated with a broad variety of tumors including lung cancer, ovarian cancer, breast cancer, Hodgkin’s lymphoma and others. PCD is a rare condition that occurs in less than 1% of cancer patients.

As is the case with other paraneoplastic syndromes, PCD is believed to be due to an autoimmune reaction targeted against components of the central nervous system, mostly to Purkinje cells.

It is thought to be triggered when tumor cells (in PCD, most commonly ovarian or breast cancer) ectopically express proteins normally expressed in the cerebellum. This is believed to trigger an anti-tumor immune response that may be clinically significant, but also an anti-neural immune response. A broad spectrum of neuronal and glial proteins has been identified as target antigens in PCD.

Neurological symptoms may include, among others, dysarthria, truncal, limb and gait ataxia and nystagmus. Symptoms often develop subacutely and progress rapidly over a period of weeks or months to a plateau period that can last for months to years and which often reflects complete loss of Purkinje cells.

Of particular note, PCD symptoms precede the diagnosis of the underlying cancer in the majority of cases, and often present insidiously and progress rapidly for weeks to months to a severely disabled state followed by a variable plateau period that can last for months to years. Therefore, newly developing cerebellar ataxia should always prompt proper diagnostic measures to exclude PCD.

Tumor removal is still the therapeutic mainstay with very early treatment being essential to prevent irreversible neuronal loss. Immunosuppressive or immunomodulatory treatments are often ineffective. There may be a role for high-dose gammaglobulin therapy in the treatment PCD, but due to the rare occurrence of this disease, controlled trials of this therapy may be difficult.

Hemangioblastomas can cause polycythemia due to ectopic production of erythropoietin as a paraneoplastic syndrome.

A leiomyoma, also known as fibroids, is a benign smooth muscle tumor that very rarely becomes cancer (0.1%). They can occur in any organ, but the most common forms occur in the uterus, small bowel, and the esophagus. Polycythemia may occur due to increased erythropoietin production as part of a paraneoplastic syndrome.

The word is from "" + "" + "", "smooth-muscle tumor".

Bronchial adenomas are adenomas in the bronchi. They may cause carcinoid syndrome, a type of paraneoplastic syndrome.

Florid cutaneous papillomatosis (also known as the Schwartz-Burgess syndrome) is an obligate paraneoplastic syndrome.

FCP begins as the sudden onset of numerous cutaneous papillomas that are clinically indistinguishable from viral warts. The papillomas range from 1 to 3 mm in diameter may spread to involve the entire body, including the face. Pruritus, which may sometimes precede the onset of FCP, is evident in the affected regions in about half of patients. Evaluation of a skin biopsy clearly distinguishes FCP from viral warts.

FCP is associated with underlying cancer of the breast, bladder, ovary, uterus, prostate, and lung. Other associated underlying malignancies include squamous cell carcinomas and lymphomas such as non-Hodgkin's lymphoma.

FCP is sometimes seen together with other signs of internal cancer, especially malignant acanthosis nigricans, tripe palms, Leser–Trélat sign, and hypertrichosis lanuginosa acquisita. FCP tends to improve in association with surgical or chemotherapeutic therapy of the underlying internal cancer. A recurrence or exacerbation of FCP may be linked with tumor regrowth or metastatic spread.

See Hepatocellular adenoma. Hepatic adenomas are a rare benign tumour of the liver, which may present with hepatomegaly or other symptoms.

Castleman disease, also known as giant lymph node hyperplasia, lymphoid hamartoma, or angiofollicular lymph node hyperplasia, is a group of uncommon lymphoproliferative disorders that share common lymph node histological features. The disease is named after Benjamin Castleman.

Castleman's disease has two main forms: It may be localized to a single lymph node (unicentric) or occur systemically (multicentric).

The unicentric form can usually be cured by surgically removing the lymph node, with a 10-year survival of 95%.

Multicentric Castleman disease (MCD) involves hyperactivation of the immune system, excessive release of proinflammatory chemicals (cytokines), proliferation of immune cells (B cells and T cells), and multiple organ system dysfunction. Castleman disease must be distinguished from other disorders that can demonstrate "Castleman-like" lymph node features, including reactive lymph node hyperplasia, autoimmune disorders, and malignancies. Multicentric Castleman's disease is associated with lymphoma and Kaposi's sarcoma.

MCD clinical features range from waxing and waning mild enlargement of the lymph nodes with B symptoms to more severe cases involving intense inflammation, widespread enlargement of lymph nodes enlargement of the liver and spleen, vascular leak syndrome with anasarca, fluid collections in the space around the lungs, and fluid collection in the abdomen's peritoneal space, organ failure, and even death. The most common 'B Symptoms' of MCD are high fevers, night sweats, weight loss, and loss of appetite. Acute episodes can display significant clinical overlap with acute viral illnesses, autoimmune diseases, hematologic malignancies, and even sepsis. Laboratory findings commonly include low red blood cell count, low or high platelet counts, low albumin, high gamma globulin levels, elevated C-reactive protein levels, elevated erythrocyte sedimentation rate, IL-6, vascular endothelial growth factor (VEGF), and fibrinogen; positive anti-nuclear antibody, anti-erythrocyte autoantibodies, and anti-platelet antibodies; and protein spilling into the urine, and polyclonal marrow plasmacytosis. Castleman disease is seen in POEMS syndrome and is implicated in 10% of cases of paraneoplastic pemphigus.

The more common features of the disease are summarized in the acronym POEMS:

Papilledema (swelling of the optic disc) often but not always due to increased intracranial pressure) is the most common ocular sign of POEMS syndrome, occurring in ≥29% of cases. Less frequent ocular findings include cystoid macular edema, serous macular detachment, infiltrative orbitopathy, and venous sinus thrombosis.

Pulmonary disease/ Polyneuropathy: The lungs are often affected at more severe stages of the illness, although since by then physical exertion is usually limited by neuropathy, shortness of breath is unusual. Pulmonary hypertension is the most serious effect on the lungs, and there may also be restriction of chest expansion or impaired gas exchange.

Organomegaly: The liver may be enlarged, and less often the spleen or lymph nodes, though these organs usually function normally.

Edema: Leakage of fluid into the tissues is a common and often severe problem. This may take several forms, including dependent peripheral edema, pulmonary edema, effusions such as pleural effusion or ascites, or generalized capillary leakage (anasarca).

Endocrinopathy: In women, amenorrhea, and in men, gynecomastia, erectile dysfunction and testicular atrophy, are common early symptoms due to dysfunction of the gonadal axis. Other hormonal problems occurring in at least a quarter of patients include type 2 diabetes, hypothyroidism, and adrenal insufficiency.

Monoclonal paraprotein: In most cases a serum myeloma protein can be detected, although this is not universal. This may represent IgG or IgA, but the light chain type is almost always lambda. This is in contrast to most paraproteinemic neuropathies, in which the paraprotein is usually an IgM antibody.

Skin changes: A very wide variety of skin problems have been reported in association with POEMS syndrome. The most common is non-specific hyperpigmentation. The fingernails may be clubbed or white. There may be thickening of the skin, excess hair or hair in unusual places (hypertrichosis), skin angiomas or hemangiomas, or changes reminiscent of scleroderma.

Neurocutaneous melanosis is associated with the presence of either giant congenital melanocytic nevi or non-giant nevi of the skin. It is estimated that neurocutaneous melanosis is present in 2% to 45% of patients with giant congenital melanocytic nevi. Patients with non-giant congenital melanocytic nevi seem to have a much lower, but undefined risk. Of these patients, only a small number are symptomatic, usually displaying symptoms before the age of 2.

These symptoms are the result of melanocytic lesions being present in the leptomeninges of the central nervous system.

Symptoms can include:

- Papilledema

- Cranial palsies

- Headache

- Vomiting

- Seizures

Others symptoms may also exist that are related to an increase in intracranial pressure. These symptoms seem to be present regardless of the malignancy of the melanin deposits within the central nervous system.

Approximately 10% of patient with neurocutaneous melanosis also present the Dandy–Walker syndrome and associated Dandy-Walker malformation. This malformation involves an enlargement of the posterior fossae and fourth ventricle along with agenesis of the cerebellar vermis. The abnormalities of the leptomeninges during fetal development due to neurocutaneous melanosis may be the cause of this increased incidence of the Dandy-Walker malformation. The development of hydrocephalus is the most common symptom associated with a combination of neurocutaneous melanosis and a Dandy-Walker malformation, occurring in about two out of three patients.

Uterine fibroids are leiomyomata of the uterine smooth muscle. As other leiomyomata, they are benign, but may lead to excessive menstrual bleeding (menorrhagia), often cause anemia and may lead to infertility.

A rare form of these tumors is uterine lipoleiomyoma—benign tumors consisting of a mixture of adipocytes and smooth muscle cells. Uterine lipoleiomyomata have been observed together with ovarian and other pathologies and some of them may develop into liposarcoma. These tumors are monoclonal, and non-random chromosomal abnormalities have been seen in 40% of the tumors.

Small-cell lung carcinoma can occur in combination with a wide variety of other histological variants of lung cancer, including extremely complex malignant tissue admixtures.

When it is found with one or more differentiated forms of lung cancer, such as squamous cell carcinoma or adenocarcinoma, the malignant tumor is then diagnosed and classified as a combined small cell lung carcinoma (c-SCLC). C-SCLC is the only currently recognized subtype of SCLC.

Although combined small-cell lung carcinoma is currently staged and treated similarly to "pure" small-cell carcinoma of the lung, recent research suggests surgery might improve outcomes in very early stages of this tumor type.

Smoking is a significant risk factor.

Symptoms and signs are as for other lung cancers. In addition, because of their neuroendocrine cell origin, small-cell carcinomas will often secrete substances that result in paraneoplastic syndromes such as Lambert-Eaton myasthenic syndrome.

The characteristic eruption is of multiple warty papules and nodules beginning on acral skin, especially the hands and wrists, and disseminating onto the skin of the entire body. These skin lesions develop on the trunk, extremities, and face, and are almost twice as common in men than in women, especially individuals aged 53–72 years. Pruritus is also associated.

The signs and symptoms of POEMS syndrome are highly variable. This often leads to long delays (e.g. 13–18 months) between the onset of initial symptoms and diagnosis. In addition to the signs and symptoms indicated by the POEMS acronym, the PEST acronym is used to describe some of the other signs and symptoms of the disease. PEST stands for Papilledema, evidence of Extravascular volume overload (ascites, pleural effusion, pericardial effusion, and lower extremity edema), Sclerotic bone lesions, and Thrombocytosis/erythrocytosis (i.e. increased in blood platelets and red blood cells). Other features of the disease include a tendency toward leukocytosis, blood clot formation, abnormal lung function (restrictive lung disease, pulmonary hypertension, and impaired lung diffusion capacity), very high blood levels of the cytokine vascular endothelial growth factor (VEGF), and an overlap with the signs and symptoms of multicentric Castleman disease.

Very rarely, the primary site for small-cell carcinoma is outside of the lungs and pleural space, it is referred to as extrapulmonary small-cell carcinoma (EPSCC). Outside of the respiratory tract, small-cell carcinoma can appear in the cervix, prostate, liver, pancreas, gastrointestinal tract, or bladder. It is estimated to account for 1,000 new cases a year in the U.S. Histologically similar to small-cell lung cancer, therapies for small-cell lung cancer are usually used to treat EPSCC. First line treatment is usually with cisplatin and etoposide. In Japan, the first line treatment is shifting to irinotecan and cisplatin.

When the primary site is in the skin, it is referred to as a cutaneous metastasis.

Bing–Neel syndrome (BNS) is an extremely rare neurologic complication of Waldenström macroglobulinemia (WM), which is a chronic lymphoproliferative disorder.

There's no clear definition of BNS but what is known so far is that unlike WM, It involves the central nervous system (CNS), infiltrated by differentiated malignant B cells and by having hyperglobulinemia. This infiltration increases blood viscosity, which impairs blood circulation through small blood vessels of the brain and the eye. Some scientists proposed that a person diagnosed with BNS is typically classified into Group A and Group B depending on whether or not plasma cells are present within the brain parenchyma, leptomeninges, dura, and/or the cerebral spinal fluid (CSF). Symptoms are diverse and nonspecific, and they can vary depending on which aspect of the CNS is being affected. Symptoms can include a range of severity of nausea and seizures. Since the symptoms vary, there are multiple treatment options to treat the symptoms for this non-curable disease. Although there is no specific set of diagnosis for BNS, different combinations of diagnostic tools are used to narrow down and conclude the presence of BNS.

Symptoms of BNS gradually progress over the span of a week or even a month, and there is typically a delay in diagnosis after the initial symptoms arise. Although BNS arises due to complications from WM, some individuals may experience symptoms of BNS without having a past history of WM.

Given that BNS is so rare, the symptoms are diverse and nonspecific. Symptoms range in severity from nausea to seizures and are characterized by how they interfere with the function of the CNS. Where certain symptoms are present depends on which branch of the CNS is being affected by plasma B-cells. People diagnosed with BNS experience some sensory symptoms as well. Some sensory symptoms include a pin and needles sensation experienced in the lower limbs, the hands, and in the arms, along with pain and extreme numbness.