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

Nevoid basal-cell carcinoma syndrome (NBCCS), also known as basal-cell nevus syndrome, multiple basal-cell carcinoma syndrome, Gorlin syndrome, and Gorlin–Goltz syndrome, is an inherited medical condition involving defects within multiple body systems such as the skin, nervous system, eyes, endocrine system, and bones. People with this syndrome are particularly prone to developing a common and usually non-life-threatening form of non-melanoma skin cancer. About 10% of people with the condition do not develop basal-cell carcinomas (BCCs).

The name "Gorlin syndrome" refers to the US-american oral pathologist and human geneticist Robert J. Gorlin (1923–2006).. The US-american dermatologist Robert W. Goltz (1923 - 2014) was his co-author, which is the basis for the term "Gorlin-Goltz syndrome'.

First described in 1960 by Gorlin and Goltz, NBCCS is an autosomal dominant condition that can cause unusual facial appearances and a predisposition for basal-cell carcinoma, a type of skin cancer which rarely spreads to other parts of the body. The prevalence is reported to be 1 case per 56,000-164,000 population. Recent work in molecular genetics has shown NBCCS to be caused by mutations in the "PTCH" (Patched) gene found on chromosome arm 9q. If a child inherits the defective gene from either parent, he or she will have the disorder.

Almost all women present with uterine fibroids, approximately 76% with dermal manifestations and 10-16% with renal tumors.

The uterine fibroids tend to occur at younger age and larger and more numerous than in general population. They may be distinguishable from sporadic fibroids by special histological features such as prominent nucleoli with perinucleolar halos.

The skin presentation is of asymmetrical, reddish-brown nodules or papules with a firm consistency, predominantly located on the limbs (multiple cutaneous leiomyoma), although they may occur anywhere, including the face. The lesions, which are typically painful and most often present during the third decade of life, are piloleiomyomata—a benign smooth muscle tumour arising from the arrectores pilorum muscles of the skin. These tumours may also arise in the tunica dartos of the scrotum and the mammillary muscle of the nipple (genital leiomyoma), the smooth muscle of blood vessels (angioleiomyoma) and the lung (pulmonary lymphangioleiomyomatosis). A pseudo-Darier sign may be present.

The renal cell carcinoma tends to be of the papillary (type 2) form and tends to occur more commonly in women than men with this syndrome. These cancers present earlier than is usual for renal cell carcinomas (typically in the twenties and thirties) and to be at relatively advanced stages at presentation. Tumours have rarely been reported in children. These tumours occur in ~20% of those with this mutation suggesting that other factors are involved in the pathogenesis.

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.

Dysplastic nevus syndrome (also known as "atypical mole syndrome (AMS)", "familial atypical multiple mole–melanoma (FAMMM) syndrome", "familial melanoma syndrome", and "B-K mole syndrome") is a cutaneous condition described in certain families, and characterized by unusual nevi and multiple inherited melanomas.

A Spitz nevus (also known as an epithelioid and spindle-cell nevus, benign juvenile melanoma, and "Spitz's juvenile melanoma") is a benign melanocytic nevus, a type of skin lesion, affecting the epidermis and dermis.

The name "juvenile melanoma" is generally no longer used as it is misleading: it is not a melanoma, it is a benign lesion; and it can also occur in adults, not only in children.

Reed’s syndrome (or familial leiomyomatosis cutis et uteri) is a rare inherited condition characterised by multiple cutaneous leiomyomas and, in women, uterine leiomyomas. It predisposes for renal cell cancer, an association denominated hereditary leiomyomatosis and renal cell cancer, and it is also associated with increased risk of uterine leiomyosarcoma. The syndrome is caused by a mutation in the fumarate hydratase gene, which leads to an accumulation of fumarate. The inheritance pattern is autosomal dominant.

The cause of Spitz nevi is not yet known. There is an association with sunburn, but causation is not established. Genetic studies of Spitz nevi have shown that most cells have the normal number of chromosomes, however a minority (25%) of cells have been shown to contain extra copies of parts of some chromosomes, such as the short arm of chromosome 11 (11p).

Spitz nevi characteristically have vertically arranged nests of nevus cells that have both a spindled and an morphology. Apoptotic cells may be seen at the dermoepidermal junction. The main histologic differential diagnoses are pigmented spindle cell nevus and malignant melanoma.

Often, this disease evolves from a precursor lesion, usually a dysplastic nevus. Otherwise it arises in previously normal skin. A prolonged radial growth phase, where the lesion remains thin, may eventually be followed by a vertical growth phase where the lesion becomes thick and nodular. As the risk of spread varies with the thickness, early SSM is more frequently cured than late nodular melanoma.

The microscopic hallmarks are:

- Large melanocytic cells with nest formation along the dermo-epidermal junction.

- Invasion of the upper epidermis in a pagetoid fashion (discohesive single cell growth).

- The pattern of rete ridges is often effaced.

- Invasion of the dermis by atypical, pleomorphic melanocytes

- Absence of the 'maturation' typical of naevus cells

- Mitoses

Trichoepithelioma is a neoplasm of the adnexa of the skin. Its appearance is similar to basal cell carcinoma.

One form has been mapped to chromosome 9p21.

Bazex–Dupré–Christol syndrome (also known as "Bazex syndrome", and "follicular atrophoderma and basal cell carcinomas") is a very rare condition inherited in an X-linked dominant fashion. Physical findings typically include follicular atrophoderma, multiple basal cell carcinomas, hypotrichosis, and hypohidrosis.

This condition should not be confused with the unrelated condition acrokeratosis paraneoplastica of Bazex, which may also be referred to Bazex syndrome.

Phakomatosis pigmentokeratotica is a rare neurocutanous condition characterized by the combination of an organoid sebaceous nevus and speckled lentiginous nevus. It is an unusual variant of epidermal naevus syndrome. It was first described by Happle "et al". It is often associated with neurological or skeletal anomalies such as hemiatrophy, dysaesthesia and hyperhidrosis in a segmental pattern, mild mental retardation, seizures, deafness, ptosis and strabismus.

Individuals with a basal-cell carcinoma typically present with a shiny, pearly skin nodule. However, superficial basal-cell cancer can present as a red patch similar to eczema. Infiltrative or morpheaform basal-cell cancers can present as a skin thickening or scar tissue – making diagnosis difficult without using tactile sensation and a skin biopsy. It is often difficult to visually distinguish basal-cell cancer from acne scar, actinic elastosis, and recent cryodestruction inflammation.

The histopathologic classification includes:

- "Nodular basal cell carcinoma" (also known as "classic basal-cell carcinoma") most commonly occurs on the sun-exposed areas of the head and neck.

- "Cystic basal cell carcinoma" is morphologically characterized by dome-shaped, blue-gray cystic nodules.

- "Cicatricial basal cell carcinoma" (also known as "morpheaform basal cell carcinoma," and "morphoeic basal cell carcinoma") is an aggressive variant with a distinct clinical and histologic appearance.

- "Infiltrative basal cell carcinoma" is an aggressive type characterized by deep infiltration.

- "Micronodular basal cell carcinoma" is characterized by a micronodular growth pattern.

- "Superficial basal cell carcinoma" (also known as "superficial multicentric basal-cell carcinoma") occurs most commonly on the trunk and appears as an erythematous patch.

- "Pigmented basal cell carcinoma" exhibits increased melanization. About 80% of all basal-cell carcinoma in Chinese are pigmented while this subtype is uncommon in white people.

- "Rodent ulcer" (also known as a "Jacob's ulcer") is a large skin lesion of nodular basal-cell carcinoma with central necrosis. Almost all cancers can metastasize except glioma (maligancy of the central nervous system) and the rodent ulcer.

- "Fibroepithelioma of Pinkus" most commonly occurs on the lower back.

- "Polypoid basal cell carcinoma" is characterized by exophytic nodules (polyp-like structures) on the head and neck.

- "Pore-like basal cell carcinoma" resembles an enlarged pore or stellate pit.

- "Aberrant basal cell carcinoma" is characterized by the formation of basal-cell carcinoma in the absence of any apparent carcinogenic factor, occurring in odd sites such as the scrotum, vulva, perineum, nipple, and axilla.

See also:

- Nevoid basal-cell carcinoma syndrome

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).

Superficial spreading melanoma (also known as "superficially spreading melanoma") (SSM) is usually characterized as the most common form of cutaneous melanoma in Caucasians. The average age at diagnosis is in the fifth decade, and it tends to occur on sun-exposed skin, especially on the backs of males and lower limbs of females.

The congenital melanocytic nevus appears as a circumscribed, light brown to black patch or plaque, potentially very heterogeneous in consistency, covering any size surface area and any part of the body.

As compared with a melanocytic nevus, congenital melanocytic nevi are usually larger in diameter and may have excess terminal hair, a condition called hypertrichosis. If over 40 cm projected adult diameter with hypertrichosis, it is sometimes called giant hairy nevus; more usually these largest forms are known as large or giant congenital melanocytic nevus. The estimated prevalence for the largest forms is 0.002% of births.

Melanocytic Nevi often grow proportionally to the body size as the child matures. As they mature, they often develop thickness, and become elevated, although these features can also be present from birth. Prominent terminal hairs often form, especially after puberty. With maturity, the nevus can have variation in color, and the surface might be textured with proliferative growths.

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. Neurocutaneous melanosis is characterized by the presence of congenital melanocytic nevi on the skin and melanocytic tumors in the leptomeninges of the central nervous system.

Sebaceous carcinoma is an uncommon and aggressive malignant cutaneous tumor. Most are typically about 10 mm in size at presentation. This neoplasm is thought to arise from sebaceous glands in the skin and, therefore, may originate anywhere in the body where these glands are found. Because the periocular region is rich in this type of gland, this region is a common site of origin. The cause of these lesions are, in the vast majority of cases, unknown. Occasional cases may be associated with Muir-Torre syndrome.

This type of cancer usually has a poor prognosis because of a high rate of metastasis.

A pigmented spindle cell nevus (also known as a "Pigmented spindle cell tumor of Reed," and "Pigmented variant of Spitz nevus") is a cutaneous condition characterized by a dark brown to black macule or papule, usually less than 6 mm.

It was characterized in 1975.

Congenital melanocytic nevi may be divided into the following types:

- "Small-sized congenital melanocytic nevus" is defined as having a diameter less than 2 cm.

- "Medium-sized congenital melanocytic nevus" is defined as having a diameter more than 2 cm but less than 20 cm.

- "Giant congenital melanocytic nevus" (also known as "Bathing trunk nevus," "Garment nevus," "Giant hairy nevus", and "Nevus pigmentosus et pilosus") is defined by one or more large, darkly pigmented and sometimes hairy patches.

Nevus sebaceus or sebaceous nevus (the first term is its Latin name, the second term is its name in English; also known as an "organoid nevus" and "nevus sebaceus of Jadassohn") is a congenital, hairless plaque that typically occurs on the face or scalp. Such nevi are present at birth, or early childhood, affecting males and females of all races equally. The condition is named for an overgrowth of sebaceous glands in the area of the nevus.

Skin growths such as benign tumors and basal cell carcinoma can arise in sebaceous nevi, usually in adulthood. Rarely, sebaceous nevi can give rise to sebaceous carcinoma. However, the rate of such malignancies is now known to be less than had been estimated. For this reason, excision is no longer automatically recommended.

Phakomatoses refers to a group of neuro-oculo-cutaneous syndromes or neurocutaneous disorders involving structures arising from the embryonic ectoderm. These multisystem disorders involve the ectodermal structures like central nervous system, skin and eyes. The lesions have a variable severity. However, it has been subsequently noted that mesodermal and endodermal tissues too are involved.

A number of genetic and acquired diseases come in this category and may affect one or more of these tissues. However, in some conditions, such as von Hippel-Lindau disease, ectodermal presentation is minimal.

Nevoid melanoma is a cutaneous condition that may resemble a Spitz nevus or an acquired or congenital melanocytic nevus.

Phakomatosis pigmentovascularis is subdivided into five types:

- Type 1 PWS + epidermal nevus

- Type 2 (most common): PWS + dermal melanocytosis +/- nevus anemicus

- Type 3: PWS + nevus spilus +/- nevus anemicus

- Type 4: PWS + nevus spilus + dermal melanocytosis +/- nevus anemicus

- Type 5: CMTC (Cutis marmorata telangiectatica congenita) + dermal melanocytosis

They all can contain capillary malformation. Type 2 is the most common and can be associated with granular cell tumor. Some further subdivide each type into categories A & B; with A representing oculocutaneous involvement and subtype B representing extra oculocutaneous involvement. Others have proposed fewer subtypes but currently this rare entity is mostly taught as having five subtypes currently.

Phakomatoses are inconsistently defined, and there is a lack of consensus about what conditions are included in this category.

Conditions included are:

- Ataxia telangiectasia

- Incontinentia pigmenti

- Neurofibromatosis

- Nevoid basal cell carcinoma syndrome

- Sturge-Weber syndrome

- Tuberous sclerosis

- Wyburn-Mason syndrome (Bonnet–Dechaume–Blanc syndrome)

- von Hippel-Lindau disease