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.

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.

Additional types of nevi do not involve disorders of pigmentation or melanocytes. These additional nevi represent hamartomatous proliferations of the epithelium, connective tissue, and vascular malformations.

Hypermelanotic nevi must be differentiated from other types of pigmented skin lesions, including:

- Lentigo simplex

- Solar lentigo

- Café au lait macule

- Ink-spot lentigo

- Mucosal melanotic macule

- Mongolian spot (dermal melanocytosis)

An Apocrine nevus is an extremely rare cutaneous condition that is composed of hyperplastic mature apocrine glands.

According to the American Academy of Dermatology, the most common types of moles are skin tags, raised moles and flat moles. Benign moles are usually brown, tan, pink or black (especially on dark-colored skin). They are circular or oval and are usually small (commonly between 1–3 mm), though some can be larger than the size of a typical pencil eraser (>5 mm). Some moles produce dark, coarse hair. Common mole hair removal procedures include plucking, cosmetic waxing, electrolysis, threading and cauterization.

Some sources equate the term mole with "melanocytic nevus". Other sources reserve the term "mole" for other purposes such as the animal of the same name.

Melanocytic nevi represent a family of lesions. The most common variants are:

- Location:

- Junctional nevus: the nevus cells are located along the junction of the epidermis and the underlying dermis. A junctional nevus is flat and brown to black.

- Compound nevus: a mixture of junctional and intradermal proliferation. Compound nevi are slightly raised and brown to black. Beauty marks are usually compound nevi of either the acquired variety or congenital variety.

- Intradermal nevus: the nevus cells are located in the dermis only. Intradermal nevi are raised; most are flesh-colored (not pigmented).

- Dysplastic nevus (nevus of Clark): usually a compound nevus with cellular and architectural dysplasia. Like typical moles, dysplastic nevi can be flat or raised. While they vary in size, dysplastic nevi are typically larger than normal moles and tend to have irregular borders and irregular coloration. Hence, they resemble melanoma, appear worrisome, and are often removed to clarify the diagnosis. Dysplastic nevi are markers of risk when they are numerous (atypical mole syndrome). According to the National Cancer Institute (NIH), doctors believe that, when part of a series or syndrome of multiple moles, dysplastic nevi are more likely than ordinary moles to develop into the most virulent type of skin cancer called melanoma.

- Blue nevus: It is blue in color as its melanocytes are very deep in the skin. The nevus cells are spindle shaped and scattered in deep layers of the dermis. The covering epidermis is normal.

- Spitz nevus: a distinct variant of intradermal nevus, usually in a child. They are raised and reddish (non-pigmented). A pigmented variant, called the 'nevus of Reed', typically appears on the leg of young women.

- Acquired nevus: Any melanocytic nevus that is not a congenital nevus or not present at birth or near birth. This includes junctional, compound and intradermal nevus.

- Congenital nevus: Small to large nevus present at or near time of birth. Small ones have low potential for forming melanomas, however the risk increases with size, as in the giant pigmented nevus.

- Giant pigmented nevus: these large, pigmented, often hairy congenital nevi. They are important because melanoma may occasionally (10 to 15%) appear in them.

- Intramucosal nevus: junctional nevus of the mucosa of the mouth or genital areas. In the mouth, they are found most frequently on the hard palate.

- Nevus of Ito and nevus of Ota: congenital, flat brownish lesions on the face or shoulder.

- Mongolian spot: congenital large, deep, bluish discoloration which generally disappears by puberty. It is named for its association with East Asian ethnic groups but is not limited to them.

- Recurrent nevus: Any incompletely removed nevus with residual melanocytes left in the surgical wound. It creates a dilemma for the patient and physician, as these scars cannot be distinguished from a melanoma.

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.

Generalized trichoepitheliomas are characterized histologically by replacement of the hair follicles by trichoepithelioma-like epithelial proliferations associated with hyperplastic sebaceous glands.

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

Mucinous nevus (also known as "Nevus mucinosus") is a rare cutaneous condition characterized by hamartoma that can be congenital or acquired.

On the shaft of the penis, Fordyce spots are more visible when the skin is stretched, and may only be noticeable during an erection.

The spots can also appear on the skin of the scrotum.

Oral Fordyce granules appear as rice-like granules, white or yellow-white in color. They are painless papules (small bumps), about 1–3 mm in greatest dimension. The most common site is along the line between the vermilion border and the oral mucosa of the upper lip, or on the buccal mucosa (inside the cheeks) in the commissural region, often bilaterally. They may also occur on the mandibular retromolar pad and tonsillar areas, but any oral surface may be involved. There is no surrounding mucosal change. Some patients will have hundreds of granules while most have only one or two.

Occasionally, several adjacent glands will coalesce into a larger cauliflower-like cluster similar to sebaceous hyperplasia of the skin. In such an instance, it may be difficult to determine whether or not to diagnose the lesion as sebaceous hyperplasia or sebaceous adenoma. The distinction may be moot because both entities have the same treatment, although the adenoma has a greater growth potential. Sebaceous carcinoma of the oral cavity has been reported, presumably arising from Fordyce granules or hyperplastic foci of sebaceous glands.

In some persons with Fordyce spots, the glands express a thick, chalky discharge when squeezed.

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.

Melanoma with features of a Spitz nevus (also known as a "Spitzoid melanoma") is a cutaneous condition characterized histologically with tissue similar to a spitz nevus and with overall symmetry and a dermal nodule of epithelioid melanocytes that do not mature with progressively deeper dermal extension.

Phakomatosis pigmentovascularis is a rare neurocutanous condition where there is coexistence of a capillary malformation (port-wine stain) with various melanocytic lesions, including dermal melanocytosis (Mongolian spots), nevus spilus, and nevus of Ota.

A sebaceous adenoma, a type of adenoma, a cutaneous condition characterized by a slow-growing tumor usually presenting as a pink, flesh-coloured, or yellow papule or nodule.

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.

Sebaceous glands are normal structures of the skin but may also be found ectopically in the mouth, where they are referred to as "oral Fordyce granules" or ectopic sebaceous glands.

On the foreskin they are called Tyson's glands, not to be confused with hirsuties coronae glandis.

When they appear on the penis, they are also called "penile sebaceous glands".

When seen as a streak of individual glands along the interface between the skin of the lip and the vermilion border, the terms Fox–Fordyce disease and Fordyce's condition have been used.

Adnexal and skin appendage neoplasms is a group of tumors which develop in the adnexal skin structures such as the sweat and sebaceous glands. An example is the hidrocystoma.

Folliculosebaceous cystic hamartoma abbreviated as (FSCH) is a rare cutaneous hamartoma consisting of dilated folliculosebaceous units invested in mesenchymal elements. it typically affects adults, have a predilection for the central face or scalp, with less than 1.5 cm dimension. Clinically, the lesions are asymptomatic, rubbery to firm in consistency, and usually occur on or above the neck in (> 90%) of cases, Histopathologically, FSCH shares several similar features to sebaceous trichofolliculoma, but it is usually possible to differentiate these two tumors.

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.

The melanocytes left behind in the wound regrow in an abnormal pattern. Rather than the even and regular lace like network, the pigments tends to grow in streaks of varying width within the scar. This is often accompanied by scarring, inflammation, and blood vessel changes – giving both the clinical and histologic impression of a melanoma or a severe dysplastic nevus. When the patient is reexamined years later without the assistance of the original biopsy report, the physician will often require the removal of the scar with the recurrent nevus to assure that a melanoma is not missed.

Syringocystadenoma papilliferum (also known as "syringadenoma papilliferum") is a benign apocrine tumor.

It can arise with nevus sebaceus.

Hair follicle nevus (also known as a "Vellus hamartoma") is a cutaneous condition that presents as a small papule from which fine hairs protrude evenly from the surface.