In this disorder lesions can occur anywhere from the stomach to the anus. The clinical presentation depends on the location of the lesions(s).

Clinically, three distinct patterns of palmoplantar keratoderma may be identified: diffuse, focal, and punctate.

Jaffe–Campanacci syndrome is one of the disorders associated with café au lait macules (CALMs). Presentations may include Intellectual Disability, disseminated non-ossifying fibromas of the long bones and jaw, hypogonadism or cryptorchidism, or giant cell granulomas of the jaw.

It was characterized in 1958 and 1983.

Familial multiple intestinal atresia is an inherited disorder where atresia occurs at multiple locations throughout the small and large intestines. It presents at birth and the prognosis is very poor with almost all those diagnosed with this condition dying with one month. It may be associated with combined immunodeficiency.

The classification of this syndrome is difficult. Three conditions are known to be caused by mutations in the" CYLD" gene: Brooke-Spiegler syndrome, multiple familial trichoepithelioma, and familial cylindromatosis. Clinically, these are distinct, but appear to arise from mutations in the same gene.

Types include:

Retinal lesions, called astrocytic hamartomas (or "phakomas"), which appear as a greyish or yellowish-white lesion in the back of the globe on the ophthalmic examination. Astrocytic hamartomas can calcify, and they are in the differential diagnosis of a calcified globe mass on a CT scan.

Nonretinal lesions associated with TSC include:

- Coloboma

- Angiofibromas of the eyelids

- Papilledema (related to hydrocephalus)

Diffuse palmoplantar keratoderma is a type of palmoplantar keratoderma that is characterized by an even, thick, symmetric hyperkeratosis over the whole of the palm and sole, usually evident at birth or in the first few months of life. Restated, diffuse palmoplantar keratoderma is an autosomal dominant disorder in which hyperkeratosis is confined to the palms and soles. The two major types can have a similar clinical appearance:

- "Diffuse epidermolytic palmoplantar keratoderma" (also known as "Palmoplantar keratoderma cum degeneratione granulosa Vörner," "Vörner's epidermolytic palmoplantar keratoderma", and "Vörner keratoderma") is one of the most common patterns of palmoplantar keratoderma, an autosomal dominant condition that presents within the first few months of life, characterized by a well-demarcated, symmetric thickening of palms and soles, often with a "dirty" snakeskin appearance due to underlying epidermolysis.

- "Diffuse nonepidermolytic palmoplantar keratoderma" (also known as "Diffuse orthohyperkeratotic keratoderma," "Hereditary palmoplantar keratoderma," "Keratosis extremitatum progrediens," "Keratosis palmoplantaris diffusa circumscripta," "Tylosis," "Unna–Thost disease", and "Unna–Thost keratoderma") is inherited as an autosomal dominant condition and is present from infancy, characterized by a well-demarcated, symmetric, often "waxy" keratoderma involving the whole of the palms and soles.

Brooke-Spiegler syndrome is a condition where multiple skin tumors develop from skin structures. Tumors commonly occurring in this syndrome include spiradenomas, trichoepitheliomas, and cylindromas. The tumors are generally benign, but may become malignant. Affected individuals are also at increased risk of developing tumors in tissues other than skin – particularly benign or malignant tumors of the salivary glands.

Tumours in Brooke-Spiegler typically appear in early adulthood and are most often found on the head and neck. In severe cases, the tumors may affect vision or hearing. They can be disfiguring and may contribute to depression or other psychological problems. For unclear reasons, females are often more severely affected than males.

Brooke-Spiegler is rare and its exact incidence is unknown.

It is inherited in an autosomal dominant fashion.

Polyps are most frequent in the stomach and large intestine, are also found in the small intestine, and are least frequent in the esophagus. A biopsy will reveal them to be hamartomas; the possibility that they progress to cancer is generally considered to be low, although it has been reported multiple times in the past. Chronic diarrhea and protein-losing enteropathy are often observed. Possible collateral features include variable anomalies of ectodermal tissues, such as alopecia, atrophy of the nails, or skin pigmentation

Some or all of the following may be seen in someone with Gorlin syndrome:

1. Multiple basal-cell carcinomas of the skin

2. Keratocystic odontogenic tumor: Seen in 75% of patients and is the most common finding. There are usually multiple lesions found in the mandible. They occur at a young age (19 yrs average).

3. Rib and vertebrae anomalies

4. Intracranial calcification

5. Skeletal abnormalities: bifid ribs, kyphoscoliosis, early calcification of falx cerebri (diagnosed with AP radiograph)

6. Distinct faces: frontal and temporoparietal bossing, hypertelorism, and mandibular prognathism

7. Bilateral ovarian fibromas

8. 10% develop cardiac fibromas

Birt–Hogg–Dubé syndrome affects the skin and increases the risk of tumors in the kidneys and lungs. The condition is characterized by multiple noncancerous dome-shaped tumors of the hair follicles (fibrofolliculomas), particularly on the face, neck, and—more rarely—the upper chest. The fibrofolliculomas are generally described as having an opaque white color or a yellowish tone and have a waxy, smooth texture. The tumors are always found on and around the nose and on and behind the outer ear. Typically, they first appear in a person's 20s or 30s, and are found in more than 80% of people with the syndrome above the age of 40. The tumors become larger and more numerous over time. Tumors differ between individuals: they may appear merged in plaques, look similar to a comedo with a plug of keratin, or include epidermoid cysts. A large number of tumors on the face can be associated with hyperseborrhea (abnormally elevated sebum production). The presence of fibrofolliculomas on a person's face can cause significant psychological distress.

Other tumors can include trichodiscomas (tumors of the hair disc, which may be identical to fibrofolliculomas), angiofibromas, and perifollicular fibromas. However, angiofibromas are more common in tuberous sclerosis. Along with the tumors, other skin conditions are seen in people with Birt–Hogg–Dubé syndrome. Approximately 40% of people or families with the disease have papules in their mouth, which can be located on the cheeks (buccal mucosa), tongue, gums, or lips. Either white or mucosa-colored, they are discrete, small, and soft and consist of fibrous tissue covered in thickened epithelium. Collagenomas of the skin are also found in some families. Many people with BHD have skin lesions that appear to be acrochordons (skin tags), but may instead be fibrofolliculomas. These lesions are usually found in the armpit, on the eyelids, and in folds of skin. Not all individuals develop the facial tumors; some families with the mutation that causes BHD develop only kidney tumors or spontaneous pneumothorax.

Some form of dermatological sign is present in 96% of individuals with TSC. Most cause no problems, but are helpful in diagnosis. Some cases may cause disfigurement, necessitating treatment. The most common skin abnormalities include:

- Facial angiofibromas ("adenoma sebaceum"): A rash of reddish spots or bumps, which appears on the nose and cheeks in a butterfly distribution, they consist of blood vessels and fibrous tissue. This potentially socially embarrassing rash starts to appear during childhood and can be removed using dermabrasion or laser treatment.

- Periungual fibromas: Also known as Koenen's tumors, these are small fleshy tumors that grow around and under the toenails or fingernails and may need to be surgically removed if they enlarge or cause bleeding. These are very rare in childhood, but common by middle age. They are generally more common on toes than on fingers, develop at 15–29 years, and are more common in women than in men. They can be induced by nail-bed trauma.

- Hypomelanic macules ("ash leaf spots"): White or lighter patches of skin, these may appear anywhere on the body and are caused by a lack of melanin. They are usually the only visible sign of TSC at birth. In fair-skinned individuals, a Wood's lamp (ultraviolet light) may be required to see them.

- Forehead plaques: Raised, discolored areas on the forehead

- Shagreen patches: Areas of thick leathery skin that are dimpled like an orange peel, and pigmented, they are usually found on the lower back or nape of the neck, or scattered across the trunk or thighs. The frequency of these lesions rises with age.

- Other skin features are not unique to individuals with TSC, including molluscum fibrosum or skin tags, which typically occur across the back of the neck and shoulders, "café au lait" spots or flat brown marks, and poliosis, a tuft or patch of white hair on the scalp or eyelids.

Typically patients present with progressive pain, often long standing and/or bony swelling and restricted range of movement in affected limb 3,12. The latter is most often the case in bones with little overlying soft tissues (e.g. short tubular bones of the hands and feet).

Most chondromyxoid fibromas are located in the metaphyseal region of long bones (60%), and may extend to the epiphyseal line and even rarely abut the articular surface 3,12. They are almost never just epiphyseal 3. The classical site is the upper 1/3rd of tibia ( which accounts for 25% of all cases) with the small tubular bones of the foot, the distal femur and pelvis being other relatively common locations 12.

Rarely occur in the skull or skull base.

Lipomatosis is believed to be an autosomal dominant condition in which multiple lipomas are present on the body. Many discrete, encapsulated lipomas form on the trunk and extremities, with relatively few on the head and shoulders. In 1993, a genetic polymorphism within lipomas was localized to chromosome 12q15, where the HMGIC gene encodes the high-mobility-group protein isoform I-C. This is one of the most commonly found mutations in solitary lipomatous tumors but lipomas often have multiple mutations. Reciprocal translocations involving chromosomes 12q13 and 12q14 have also been observed within.

Although this condition is benign, it can sometimes be very painful depending on location of the lipomas. Some patients who are concerned with cosmetics seek removal of individual lipomas. Removal can include simple excision, endoscopic removal, or liposuction.

Other entities which are accompanied by multiple lipomas include Proteus syndrome, Cowden syndrome and related disorders due to PTEN gene mutations, benign symmetric lipomatosis (Madelung disease),Dercum's Disease, familial lipodystrophy, hibernomas, epidural steroid injections with epidural lipomatosis, and familial angiolipomatosis.

Acrokeratoelastoidosis of Costa (also known as "Keratoelastoidosis marginalis") is a familial condition characterized by multiple keratotic papules on the dorsum of the hands and feet, palms, soles, in which electron microscopy shows rarified, abnormal elastic tissue.

It was characterized in 1953.

Treatments such as liquid nitrogen, salicylic acid, tretinoin, and prednisone have been tried, though with limited success.

Diffuse infantile fibromatosis is a condition affecting infants during the first 3 years of life. It is usually confined to the muscles of the arms, neck, and shoulder area. There is a multicentric infiltration of muscle fibers with fibroblasts resembling those seen in aponeurotic fibromas.

AMS has been described by multiple authors and institutions, and various definitions have been adopted. According to Newton et al., a scoring system allotting one point per feature establishes AMS with scores greater than or equal to 3. The features include: 1) two or more clinically atypical nevi, 2) more than 100 nevi in patients between 20 and 50 years of age, 3) more than 50 nevi in patients under 20 years of age or more than 50 years of age, 4) more than one nevus in buttocks or instep, 5) nevi on the anterior scalp, 6) one or more pigmented lesions in the iris.

The Classical (1990) definition uses the following criteria: 1) 100 or more melanocytic nevi, 2) one or more melanocytic nevi greater than or equal to 8mm in its largest diameter, and 3) one or more clinically atypical melanocytic nevi.

The National Institutes of Health (NIH) Consensus 1992 definition, which is still controversial, requires a family history of melanoma, in addition to a large number of melanocytic nevi (often greater than 50) and melanocytic nevi that present certain histological features.

People over 20 years of age with Birt–Hogg–Dubé syndrome have an increased risk of developing slow-growing kidney tumors (chromophobe renal carcinoma and renal oncocytoma, respectively), kidney cysts, and possibly tumors in other organs and tissues. These tumors often occur in both kidneys and in multiple locations in each kidney. The average number of kidney tumors found in a person with BHD is 5.3, though up to 28 tumors have been found. Hybrid oncocytoma/chromophobe carcinoma, found in 50% of cases, is the most commonly found cancer, followed by chromophobe renal carcinoma, clear cell renal carcinoma, renal oncocytoma, and papillary renal cell carcinoma. People over 40 years old and men are more likely to develop kidney tumors, which are diagnosed at a median age of 48. Kidney cancer associated with BHD have been diagnosed in people at ages as young as 20.

In general, people with Birt–Hogg–Dubé syndrome are at roughly seven times the risk of kidney cancer compared to the unaffected population. Estimates of the incidence among people with the disease range from 14%–34%. Rarely, it is associated with clear cell renal cell carcinoma and papillary renal cell carcinoma. If it develops in someone with BHD, renal cell carcinoma occurs later in life and has a poor prognosis. Though the types of tumor typically associated with BHD are considered less aggressive, cases of advanced or metastatic kidney cancer have been observed in people with the syndrome. Both benign and cancerous tumors can reduce kidney function over time as they grow larger.

Cronkhite–Canada syndrome is a rare syndrome characterized by multiple polyps of the digestive tract. It is sporadic (i.e. it does not seem to be a hereditary disease), and it is currently considered acquired and idiopathic (i.e. cause remains unknown).

About two-thirds of patients are of Japanese descent and the male to female ratio is 2:1. It was characterized in 1955.

CVG is classified according to the presence, or lack of underlying cause. Studies suggest that CVG often occurs in individuals in a secondary form to other ailments. However, the condition can also be present on its own. CVG can be classified into two forms: ‘primary’ (essential and non-essential) and ‘secondary’.

The classifications are:

Primary essential CVG is where the cause of the condition in unknown. It has no other associated abnormalities. This occurs mainly in men, with a male:female ratio of 5 or 6:1, and develops during or soon after puberty. Because of the slow progression of the condition, which usually occurs without symptom, it often passes unnoticed in the early stage

Primary non essential CVG can be associated with neuropsychiatric disorders including cerebral palsy, epilepsy, seizures and ophthalmologic abnormalities, most commonly cataracts.

Secondary CVG occurs as a consequence of a number of diseases or drugs that produce changes in scalp structure. These include: acromegaly (excessive growth hormone levels due to pituitary gland tumours), excessive drug use that mimics acromegaly (including the injection of growth hormone itself and drugs that stimulate growth hormone output, such as GHRP-6 and CJC-1295), melanocytic naevi (moles), birthmarks (including connective tissue naevi, fibromas and naevus lipomatosus), and inflammatory processes (e.g., eczema, psoriasis, Darier disease, folliculitis, impetigo, atopic dermatitis, acne).

The majority of cases occur in the second and third decades, with approximately 75% of cases occurring before the age of 30 years 1,12-15. There is no recognised gender predilection. Examples have however been seen in patients up to the age of 75 years. In some series there is a male predilection 12 whilst in others no such distribution is found 2

Neurocristopathy is a diverse class of pathologies that may arise from defects in the development of tissues containing cells commonly derived from the embryonic neural crest cell lineage. The term was coined by Robert P. Bolande in 1974.

Accepted examples are piebaldism, Waardenburg syndrome, Hirschsprung disease, Ondine's curse (congenital central hypoventilation syndrome), pheochromocytoma, paraganglioma, Merkel cell carcinoma, multiple endocrine neoplasia, neurofibromatosis type I, CHARGE syndrome, familial dysautonomia, DiGeorge syndrome, Axenfeld-Rieger syndrome, Goldenhar syndrome (a.k.a. hemifacial microsomia), craniofrontonasal syndrome, congenital melanocytic nevus, melanoma, and certain congenital heart defects of the outflow tract, in particular.

Multiple sclerosis has also been suggested as being neurocristopathic in origin.

The usefulness of the definition resides in its ability to refer to a potentially common etiological factor for certain neoplasms and/or congenital malformation associations that are otherwise difficult to group with other means of nosology.

In 1820 Norris reported the first case of what is now recognized as FAMMM (12). He described a 59-year-old man with melanoma, a high total body mole count, and family history of the same.

Rowell's Syndrome was described by Professor Neville Rowell and colleagues in 1963. Patients with the syndrome have lupus erythematosus (discoid or systemic), annular lesions of the skin like erythema multiforme associated with a characteristic pattern of immunological abnormalities. It is uncommon but occurs worldwide.

Rowell's syndrome has been reported to occur with all subtypes of LE (systemic, acute, subacute or discoid).

Knuckle pads (also known as "Heloderma", meaning similar to the skin of the Gila monster lizard for which it is named) are circumscribed, keratotic, fibrous growths over the dorsa of the interphalangeal joints.

Knuckle pads are sometimes associated with Dupuytren's contracture and camptodactyly, and histologically, the lesions are fibromas.

Knuckle pads are generally non-responsive to treatment, including corticosteroids, and tend to recur after surgery; however, there has been some effectiveness with intralesional fluorouracil.