Carney triad (CT) is characterized by the coexistence of three types of neoplasms, mainly in young women, including gastric gastrointestinal stromal tumor, pulmonary chondroma, and extra-adrenal paraganglioma. The underlying genetic defect remains elusive. CT is distinct from Carney complex, and the Carney-Stratakis syndrome.

The spotty skin pigmentation and lentigines occur most commonly on the face, especially on the lips, eyelids, conjunctiva and oral mucosa. Cardiac myxomas may lead to embolic strokes and heart failure and may present with fever, joint pain, shortness of breath, diastolic rumble and tumor plop. Myxomas may also occur outside the heart, usually in the skin and breast. Endocrine tumors may manifest as disorders such as Cushing syndrome. The most common endocrine gland manifestation is an ACTH-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD).

The LAMB acronym refers to lentigines, atrial myxomas, and blue nevi. NAME refers to nevi, atrial myxoma, myxoid neurofibromas, and ephelides.

Testicular cancer, particularly Sertoli cell type, is associated with Carney syndrome. Thyroid and pancreas cancer may also occur.

Although J Aidan Carney also described Carney's triad it is entirely different.

The Carney complex is a distinct entity, characterized by myxomatous neoplasms (cardiac, endocrine, cutaneous and neural), and a host of pigmented lesions of the skin and mucosae, including the rarely occurring epitheloid blue nevus.

Carney complex and its subsets LAMB syndrome and NAME syndrome are autosomal dominant conditions comprising myxomas of the heart and skin, hyperpigmentation of the skin (lentiginosis), and endocrine overactivity. It is distinct from Carney's triad. Approximately 7% of all cardiac myxomas are associated with Carney complex.

GISTs may present with trouble swallowing, gastrointestinal bleeding, or metastases (mainly in the liver). Intestinal obstruction is rare, due to the tumor's outward pattern of growth. Often, there is a history of vague abdominal pain or discomfort, and the tumor has become rather large by time the diagnosis is made.

The term multiple endocrine neoplasia (MEN) encompasses several distinct syndromes featuring tumors of endocrine glands, each with its own characteristic pattern. In some cases, the tumors are malignant, in others, benign. Benign or malignant tumors of nonendocrine tissues occur as components of some of these tumor syndromes.

MEN syndromes are inherited as autosomal dominant disorders.

Adrenocortical carcinoma may present differently in children and adults. Most tumors in children are functional, and virilization is by far the most common presenting symptom, followed by Cushing's syndrome and precocious puberty. Among adults presenting with hormonal syndromes, Cushing's syndrome alone is most common, followed by mixed Cushing's and virilization (glucocorticoid and androgen overproduction). Feminization and Conn syndrome (mineralocorticoid excess) occur in less than 10% of cases. Rarely, pheochromocytoma-like hypersecretion of catecholamines has been reported in adrenocortical cancers. Non-functional tumors (about 40%, authorities vary) usually present with abdominal or flank pain, varicocele and renal vein thrombosis or they may be asymptomatic and detected incidentally.

All patients with suspected adrenocortical carcinoma should be carefully evaluated for signs and symptoms of hormonal syndromes. For Cushing's syndrome (glucocorticoid excess) these include weight gain, muscle wasting, purple lines on the abdomen, a fatty "buffalo hump" on the neck, a "moonlike" face, and thinning, fragile skin. Virilism (androgen excess) is most obvious in women, and may produce excess facial and body hair, acne, enlargement of the clitoris, deepening of the voice, coarsening of facial features, cessation of menstruation. Conn syndrome (mineralcorticoid excess) is marked by high blood pressure which can result in headache and hypokalemia (low serum potassium, which can in turn produce muscle weakness, confusion, and palpitations) low plasma renin activity, and high serum aldosterone. Feminization (estrogen excess) is most readily noted in men, and includes breast enlargement, decreased libido and impotence.

The World Health Organization (WHO) classification scheme places neuroendocrine tumors into three main categories, which emphasize the tumor grade rather than the anatomical origin:

- well-differentiated neuroendocrine tumours, further subdivided into tumors with benign and those with uncertain behavior

- well-differentiated (low grade) neuroendocrine carcinomas with low-grade malignant behavior

- poorly differentiated (high grade) neuroendocrine carcinomas, which are the large cell neuroendocrine and small cell carcinomas.

Additionally, the WHO scheme recognizes mixed tumors with both neuroendocrine and epithelial carcinoma features, such as goblet cell cancer, a rare gastrointestinal tract tumor.

Placing a given tumor into one of categories depends on well-defined histological features: size, lymphovascular invasion, mitotic counts, Ki-67 labelling index, invasion of adjacent organs, presence of metastases and whether they produce hormones.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. GISTs arise in the smooth muscle pacemaker interstitial cell of Cajal, or similar cells. They are defined as tumors whose behavior is driven by mutations in the KIT gene (85%), PDGFRA gene (10%), or BRAF kinase (rare). 95% of GISTs stain positively for KIT (CD117). Most (66%) occur in the stomach and gastric GISTs have a lower malignant potential than tumors found elsewhere in the GI tract.

Conceptually, there are two main types of NET within this category: those which arise from the gastrointestinal (GI) system and those that arise from the pancreas. In usage, the term "carcinoid" has often been applied to both, although sometimes it is restrictively applied to NETs of GI origin (as herein), or alternatively to those tumors which secrete functional hormones or polypeptides associated with clinical symptoms, as discussed.

Primary pigmented nodular adrenocortical disease (PPNAD) was first coined in 1984 by Carney et al. it often occurs in association with Carney complex (CNC). CNC is a rare syndrome that involves the formation of abnormal tumours that cause endocrine hyperactivity.

PPNAD arises due to the enlargement of the cortex of the adrenal glands, resulting in Cushing's syndrome that is independent of the pituitary hormone ACTH.

A useful mnemonic to remember the associated neoplasias is below:

MEN I (3 Ps) - Pituitary, Parathyroid, Pancreatic

MEN IIa (2Ps, 1M) - Pheochromocytoma, Parathyroid, Medullary Thyroid Ca

MEN IIb (1P, 2Ms) - Pheochromocytoma, Medullary Thyroid Ca, Marfanoid habitus/mucosal neuroma

A cancer syndrome or family cancer syndrome is a genetic disorder in which inherited genetic mutations in one or more genes predispose the affected individuals to the development of cancers and may also cause the early onset of these cancers. Cancer syndromes often show not only a high lifetime risk of developing cancer, but also the development of multiple independent primary tumors. Many of these syndromes are caused by mutations in tumor suppressor genes, genes that are involved in protecting the cell from turning cancerous. Other genes that may be affected are DNA repair genes, oncogenes and genes involved in the production of blood vessels (angiogenesis). Common examples of inherited cancer syndromes are hereditary breast-ovarian cancer syndrome and hereditary non-polyposis colon cancer (Lynch syndrome).

Adrenocortical carcinoma (ACC, adrenal cortical carcinoma, adrenal cortical cancer, adrenal cortex cancer, etc.) is an aggressive cancer originating in the cortex (steroid hormone-producing tissue) of the adrenal gland. Adrenocortical carcinoma is a rare tumor, with incidence of 1–2 per million population annually. Adrenocortical carcinoma has a bimodal distribution by age, with cases clustering in children under 5, and in adults 30–40 years old. Adrenocortical carcinoma is remarkable for the many hormonal syndromes which can occur in patients with steroid hormone-producing ("functional") tumors, including Cushing's syndrome, Conn syndrome, virilization, and feminization. Adrenocortical carcinoma has often invaded nearby tissues or metastasized to distant organs at the time of diagnosis, and the overall 5-year survival rate is only 20–35%. The widely used angiotensin-II-responsive steroid-producing cell line H295R was originally isolated from a tumor diagnosed as adrenocortical carcinoma.

PPNAD is a rare cause of high cortisol levels in the blood and often manifests as ACTH-independent Cushing's syndrome. The effects of PPNAD can often be cyclical so the symptoms of Cushing's syndrome will not always be as severe, which may complicate diagnosis. The classic symptoms of Cushing's syndrome include rapid central weight gain, a puffy red face and a buffalo hump at the back of the neck due to fat deposits. Skin changes in Cushing's syndrome include thinning and bruising easily, developing striae and hyperpigmentation at skin folds. The hormonal changes can lead to hirsuitism, males developing breast tissue, females no longer having periods and both sexes may become infertile. High cortisol levels can lead to psychological disturbances such as anxiety or depression and insomnia. Bone health can deteriorate, leading to an increased fracture risk in people with Cushing's syndrome. PPNAD is unique as it often causes Cushing's at a young age, in children and adolescents. In addition to the other symptoms of Cushing's syndrome, the patient may have a short stature due to interrupted growth because of ACTH suppression.

In 90% of people with PPNAD it is associated with Carney Complex. Carney Complex is usually inherited, however it can also occur sporadically. A visible sign of Carney complex is abnormal skin hyperpigmentation. There may also be myxomas which can appear as lumps in the skin and breast as well as often being present in the heart, which can lead to multiple cardiovascular problems. The majority of people with PPNAD will have some of these signs/symptoms due to the strong association between PPNAD and Carney Complex.

Hereditary cancer syndromes underlie 5 to 10% of all cancers. Scientific understanding of cancer susceptibility syndromes is actively expanding: additional syndromes are being found, the underlying biology is becoming clearer, and commercialization of diagnostic genetics methodology is improving clinical access. Given the prevalence of breast and colon cancer, the most widely recognized syndromes include hereditary breast-ovarian cancer syndrome (HBOC) and hereditary non-polyposis colon cancer (HNPCC, Lynch syndrome).

Some rare cancers are strongly associated with hereditary cancer predisposition syndromes. Genetic testing should be considered with adrenocortical carcinoma; carcinoid tumors; diffuse gastric cancer; fallopian tube/primary peritoneal cancer; leiomyosarcoma; medullary thyroid cancer; paraganglioma/pheochromocytoma; renal cell carcinoma of chromophobe, hybrid oncocytic, or oncocytoma histology; sebaceous carcinoma; and sex cord tumors with annular tubules. Primary care physicians can identify people who are at risk of heridatary cancer syndrome.

Generalized lentiginosis is a cutaneous condition that will occasionally present without other associated abnormalities. It may be caused by carney complex, LEOPARD syndrome or Peutz–Jeghers syndrome.

Hormone secreting pituitary adenomas cause one of several forms of hyperpituitarism. The specifics depend on the type of hormone. Some tumors secrete more than one hormone, the most common combination being GH and prolactin, which present as unexpected bone growth and unexpected lactation (in both men and women).

A patient with pituitary adenoma may present with visual field defects, classically bitemporal hemianopsia. It arises from the compression of the optic nerve by the tumor. The specific area of the visual pathway at which compression by these tumours occurs is at the optic chiasma.

The anatomy of this structure causes pressure on it to produce a defect in the temporal visual field on both sides, a condition called bitemporal hemianopsia. If originating superior to the optic chiasm, more commonly in a craniopharyngioma of the pituitary stalk, the visual field defect will first appear as bitemporal inferior quadrantanopia, if originating inferior to the optic chiasm the visual field defect will first appear as bitemporal superior quadrantanopia. Lateral expansion of a pituitary adenoma can also compress the abducens nerve, causing a lateral rectus palsy.

Also, a pituitary adenoma can cause symptoms of increased intracranial pressure.

Prolactinomas often start to give symptoms especially during pregnancy, when the hormone progesterone increases the tumor's growth rate.

Various types of headaches are common in patients with pituitary adenomas. The adenoma may be the prime causative factor behind the headache or may serve to exacerbate a headache caused by other factors. Amongst the types of headaches experienced are both chronic and episodic migraine, and more uncommonly various unilateral headaches; primary stabbing headache, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) - another type of stabbing headache characterized by short stabs of pain -, cluster headache, and hemicrania continua (HS).

Non-secreting adenomas can go undetected for an extended time because no obvious abnormalities are seen; the gradual reduction in normal activities due to decreased production of hormones is rather less evident. For example, insufficient adrenocorticotropic hormone means that the adrenal glands will not produce sufficient cortisol, resulting in slow recovery from illness, inflammation and chronic fatigue; insufficient growth hormone in children and adolescents leads to diminished stature but which can have many other explanations.

Pituitary adenomas are tumors that occur in the pituitary gland. Pituitary adenomas are generally divided into three categories dependent upon their biological functioning: benign adenoma, invasive adenoma, and carcinomas. Most adenomas are benign, approximately 35% are invasive and just 0.1% to 0.2 are carcinomas. Pituitary adenomas represent from 10% to 25% of all intracranial neoplasms and the estimated prevalence rate in the general population is approximately 17%.

Non-invasive and non-secreting pituitary adenomas are considered to be benign in the literal as well as the clinical sense; however a recent meta-analysis (Fernández-Balsells, "et al." 2011) of available research has shown there are to date scant studies – of poor quality – to either support or refute this assumption.

Adenomas which exceed in size are defined as "macroadenomas", with those smaller than 10 mm referred to as "microadenomas". Most pituitary adenomas are microadenomas, and have an estimated prevalence of 16.7% (14.4% in autopsy studies and 22.5% in radiologic studies). A majority of pituitary microadenomas often remain undiagnosed and those that are diagnosed are often found as an "incidental finding", and are referred to as "incidentalomas".

Pituitary macroadenomas are the most common cause of hypopituitarism, and in the majority of cases they are non-secreting adenomas.

While pituitary adenomas are common, affecting approximately one in 6 of the general population, clinically active pituitary adenomas that require surgical treatment are more rare, affecting approximately one in 1000 of the general population.

A lentigo () (plural lentigines, ) is a small pigmented spot on the skin with a clearly defined edge, surrounded by normal-appearing skin. It is a harmless (benign) hyperplasia of melanocytes which is linear in its spread. This means the hyperplasia of melanocytes is restricted to the cell layer directly above the basement membrane of the epidermis where melanocytes normally reside. This is in contrast to the "nests" of multi-layer melanocytes found in moles (melanocytic nevi). Because of this characteristic feature, the adjective "lentiginous" is used to describe other skin lesions that similarly proliferate linearly within the basal cell layer.

Lentigines are distinguished from freckles (ephelis) based on the proliferation of melanocytes. Freckles have a relatively normal number of melanocytes but an increased "amount" of melanin. A lentigo has an increased "number" of melanocytes. Freckles will increase in number and darkness with sunlight exposure, whereas lentigines will stay stable in their color regardless of sunlight exposure.

Lentigines by themselves are benign, however one might desire the removal or treatment of some of them for cosmetic purposes. In this case they can be removed surgically, or lightened with the use of topical depigmentation agents. Some common depigmentation agents such as azelaic acid and kojic acid seem to be inefficient in this case, however other agents might work well (4% hydroquinone, 5% topical cysteamine, 10% topical ascorbic acid).

Conditions characterized by lentigines include:

- Lentigo simplex

- Solar lentigo (Liver spots)

- PUVA lentigines

- Ink spot lentigo

- LEOPARD syndrome

- Mucosal lentigines

- Multiple lentigines syndrome

- Moynahan syndrome

- Generalized lentiginosis

- Centrofacial lentiginosis

- Carney complex

- Inherited patterned lentiginosis in black persons

- Partial unilateral lentiginosis

- Peutz-Jeghers syndrome

- Lentigo maligna

- Lentigo maligna melanoma

- Acral lentiginous melanoma

A cutaneous myxoma, a.k.a. superficial angiomyxoma, consists of a multilobulated myxoid mass containing stellate or spindled fibroblasts with pools of mucin forming cleft-like spaces. There is often a proliferation of blood vessels and an inflammatory infiltrate. Staining is positive for vimentin, negative for cytokeratin and desmin, and variable for CD34, Factor VIIIa, SMA, MSA and S-100.

Clinically, it may present as solitary or multiple flesh-colored nodules on the face, trunk, or extremities. It may occur as part of the Carney complex, and is sometimes the first sign. Local recurrence is common.

Blue nevi may be divided into the following types:

- A "patch blue nevus" (also known as an "acquired dermal melanocytosis", and "dermal melanocyte hamartoma") is a cutaneous condition characterized by a diffusely gray-blue area that may have superimposed darker macules.

- A "blue nevus of Jadassohn–Tièche" (also known as a "common blue nevus", and "nevus ceruleus") is a cutaneous condition characterized by a steel-blue papule or nodule.

- A "cellular blue nevus" is a cutaneous condition characterized by large, firm, blue or blue-black nodules.

- An "epithelioid blue nevus" is a cutaneous condition most commonly seen in patients with the Carney complex.

- A "deep penetrating nevus" is a type of benign melanocytic skin tumor characterized, as its name suggests, by penetration into the deep dermis and/or subcutis. Smudged chromatic is a typical finding. In some cases mitotic figures or atypical melanocytic cytology are seen, potentially mimicking a malignant melanoma. Evaluation by an expert skin pathologist is advisable in some cases to help differentiate from invasive melanoma.

- An "amelanotic blue nevus" (also known as a "hypomelanotic blue nevus") is a cutaneous condition characterized by mild atypia and pleomorphism.

- A "malignant blue nevus" is a cutaneous condition characterized by a sheet-like growth pattern, mitoses, necrosis, and cellular atypia.

Papillary thyroid cancer gets its name from the among its cells, visible on microscopy. Features include:

- Characteristic Orphan Annie eye nuclear inclusions (nuclei with uniform staining, which appear empty due to powdery chromatin and marginal micronucleoli) and psammoma bodies on light microscopy. The former is useful in identifying the follicular variant of papillary thyroid carcinomas.

- Lymphatic spread is more common than hematogenous spread

- Multifocality is common

- The so-called Lateral Aberrant Thyroid is actually a lymph node metastasis from papillary thyroid carcinoma.

- Papillary microcarcinoma is a subset of papillary thyroid cancer defined as measuring less than or equal to 1 cm. The highest incidence of papillary thyroid microcarcinoma in an autopsy series was reported by Harach et al. in 1985, who found 36 of 101 consecutive autopsies to have an incidental microcarcinoma. Michael Pakdaman et al. report the highest incidence in a retrospective surgical series at 49.9 percent of 860 cases. Management strategies for incidental papillary microcarcinoma on ultrasound (and confirmed on FNAB) range from total thyroidectomy with radioactive iodine ablation to observation alone. Harach et al. suggest using the term "occult papillary tumor" to avoid giving patients distress over having cancer. It was Woolner et al. who first arbitrarily coined the term "occult papillary carcinoma" in 1960, to describe papillary carcinomas ≤ 1.5 cm in diameter.

Several variants are recognized, although classical papillary thyroid carcinoma is the most frequent; microscopic, follicular variant, diffuse sclerosing variant, tall cell variant, columnar cell variant, hobnail variant, among others. The encapsulated follicular variant, specifically when noninvasive, has been newly reclassified as the noninvasive follicular thyroid neoplasm with papillary-like nuclear features.

Although papillary carcinoma has a propensity to invade lymphatics, it is less likely to invade blood vessels.

These kinds of tumors are most commonly unencapsulated, and they have a high tendency to metastasize locally to lymph nodes, which may produce cystic structures near the thyroid that are difficult to diagnose because of the paucity of malignant tissue. Furthermore, papillary tumors may metastasize to the lungs and produce a few nodules or the lung fields may exhibit a snowflake appearance throughout.

Other characteristics of the papillary carcinoma is that E.M. shows increased mitochondria, increased RER, as well as increased apical microvilli. Moreover, papillary carcinomas have an indolent growth, and 40 percent of cases spread out of the capsule.

Papillary thyroid cancer or papillary thyroid carcinoma is the most common type of thyroid cancer, representing 75 percent to 85 percent of all thyroid cancer cases. It occurs more frequently in women and presents in the 20–55 year age group. It is also the predominant cancer type in children with thyroid cancer, and in patients with thyroid cancer who have had previous radiation to the head and neck. It is often well-differentiated, slow-growing, and localized, although it can metastasize.

Blue nevus (also known as "blue neuronevus", "dermal melanocytoma", and "nevus bleu") is a type of melanocytic nevus. The blue colour is caused by the pigment being deeper in the skin than in ordinary nevi. In principle they are harmless but they can sometimes be mimicked by malignant lesions, i.e. some melanomas can look like a blue nevus.