There are three distinct types of lymphangioma, each with their own symptoms. They are distinguished by the depth and the size of abnormal lymph vessels, but all involve a malformation of the lymphic system. Lymphangioma circumscriptum can be found on the skin's surface, and the other two types of lymphangiomas occur deeper under the skin.

- Lymphangioma circumscriptum, a microcystic lymphatic malformation, resembles clusters of small blisters ranging in color from pink to dark red. They are benign and do not require medical treatment, although some patients may choose to have them surgically removed for cosmetic reasons.

- Cavernous lymphangiomas are generally present at birth, but may appear later in the child's life. These bulging masses occur deep under the skin, typically on the neck, tongue and lips, and vary widely in size, ranging from as small as a centimeter in diameter to several centimeters wide. In some cases, they may affect an entire extremity such as a hand or foot. Although they are usually painless, the patient may feel mild pain when pressure is exerted on the area. They come in the colors white, pink, red, blue, purple, and black; and the pain lessens the lighter the color of the bump.

- Cystic hygroma shares many commonalities with cavernous lymphangiomas, and some doctors consider them to be too similar to merit separate categories. However, cystic lymphangiomas usually have a softer consistency than cavernous lymphangiomas, and this term is typically the one that is applied to lymphangiomas that develop in fetuses. They usually appear on the neck (75%), arm pit or groin areas. They often look like swollen bulges underneath the skin.

Many of the symptoms of schwannomatosis overlap with NF2.

- Schwannomas occur instead of the neurofibromas that are hallmarks of neurofibromatosis Type 1 (NF1).

- Multiple schwannomas manifest throughout the body or in isolated regions.

- The schwannomas develop on cranial, spinal and peripheral nerves.

- Chronic pain, and sometimes numbness, tingling and weakness.

- About 1/3 of patients have segmental schwannomatosis, which means that the schwannomas are limited to a single part of the body, such as an arm, a leg or the spine.

- There are several cases where people with schwannomatosis have developed a vestibular schwannoma (acoustic neuroma). An acoustic neuroma is a schwannoma on the vestibular nerve in the brain. This nerve is involved in hearing and patients with vestibular schwannomas experience hearing loss. However, bilateral vestibular schwannomas (vestibular schwannomas on both sides of the brain) do not occur in schwannomatosis. Juvenile vestibular tumors do not occur either.

- Patients with schwannomatosis do not have learning disabilities related to the disease.

- Symptoms are sometimes brought on by hormonal changes such as puberty and pregnancy.

Lymphangiomas have traditionally been classified into three subtypes: "capillary" and "cavernous lymphangiomas" and cystic hygroma. This classification is based on their microscopic characteristics. A fourth subtype, the "hemangiolymphangioma" is also recognized.

- Capillary lymphangiomas

- Cavernous lymphangiomas

- Cystic hygromas

- Hemangiolymphangioma

Lymphangiomas may also be classified into "microcystic", "macrocystic", and "mixed" subtypes, according to the size of their cysts.

- Microcystic lymphangiomas

- Macrocystic lymphangiomas

- Mixed lymphangiomas

Finally, lymphangiomas may be described in stages, which vary by location and extent of disease. In particular, stage depends on whether lymphangiomas are present above or "superior" to the hyoid bone ("suprahyoid"), below or "inferior" to the hyoid bone ("infrahyoid"), and whether the lymphangiomas are on one side of the body ("unilateral") or both ("bilateral").

- Stage I: Unilateral infrahyoid.

- Stage II: Unilateral suprahyoid.

- Stage III: Unilateral suprahyoid and infrahyoid.

- Stage IV: Bilateral suprahyoid.

- Stage V: Bilateral suprahyoid and infrahyoid.

A Cystic lymphatic malformation is a deep-seated, typically multilocular, ill-defined soft-tissue mass that is painless and covered by normal skin. These malformations may further be divided into macrocystic lymphatic malformations and microcystic lymphatic malformations.

Schwannomatosis is one form of a genetic disorder called neurofibromatosis (NF) that has only recently been recognized. Originally described in Japanese patients, it consists of multiple cutaneous schwannomas, central nervous system tumors, and other neurological complications, excluding hallmark signs of NF. It is a rare disorder, affecting only around 1 in 40,000 individuals.

Schwannomas are mostly benign tumors that commonly occur in individuals with NF2 and schwannomatosis (sometimes called neurofibromatosis type III). Schwann cells are glial cells that myelinate the axons of nerve cells. Myelin is a lipid covering that speeds the conduction of action potentials. When Schwann cells proliferate out of control in an encapsulation it is called a schwannoma. Although schwannomas are benign they become detrimental when the growing tumor compresses the nerve. Schwannomas on sensory nerve axons cause chronic severe pain. Treatment options for schwannomas are to surgically remove them, have radiation, cyberknife or Intracapsular Enucleation. Previous designations for schwannomas include neurinoma and neurilemmoma.

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.

Cystic hygromas are increasingly diagnosed by prenatal ultrasonography. A common symptom is a neck growth. It may be found at birth, or discovered later in an infant after an upper respiratory tract infection. Cystic hygromas can grow very large and may affect breathing and swallowing. Some symptoms may include a mass or lump in the mouth, neck, cheek, or tongue. It feels like a large fluid-filled sac. In addition, cystic hygromas can be found in other body parts such as the arm, chest, legs, groin, and buttocks. Cystic hygromas are also often seen in Turner's syndrome, although a patient who does not have Turner's syndrome can present with this condition.

Pancreatic serous cystadenoma, also known as serous cystadenoma of the pancreas and serous microcystic adenoma, a benign tumour of pancreas. It is usually found in the head of the pancreas, and may be associated with von Hippel-Lindau syndrome.

In contrast to some of the other cyst-forming tumors of the pancreas (such as the intraductal papillary mucinous neoplasm and the mucinous cystic neoplasm), serous cystic neoplasms are almost always entirely benign. There are some exceptions; rare case reports have described isolated malignant serous cystadenocarcinomas. In addition, serous cystic neoplasms slowly grow, and if they grow large enough they can press on adjacent organs and cause symptoms.

Pathologists classify serous cystic neoplasms into two broad groups. Those that are benign, that have not spread to other organs, are designated "serous cystadenoma". Serous cystadenomas can be further sub-typed into microcystic, oligocystic (or macrocystic), solid, mixed serous-endocrine neoplasm, and VHL-associated serous cystic neoplasm. This latter classification scheme is useful because it highlights the range of appearances and the clinical associations of these neoplasms. Serous cystic neoplasms that have spread ("metastasized") to another organ are considered malignant and are designated "serous cystadenocarcinoma".

A cystic hygroma, also known as cystic lymphangioma and macrocystic lymphatic malformation, is an often congenital multiloculated lymphatic lesion that can arise anywhere, but is classically found in the left posterior triangle of the neck and armpits. This is the most common form of lymphangioma. It contains large cyst-like cavities containing lymph, a watery fluid that circulates throughout the lymphatic system. Microscopically, cystic hygroma consists of multiple locules filled with lymph. In the depth, the locules are quite big but they decrease in size towards the surface.

Cystic hygromas are benign, but can be disfiguring. It is a condition which usually affects children; very rarely it can present in adulthood.

Cystic hygroma is also known as lymphatic malformation. Currently, the medical field prefers to use the term lymphatic malformation because the term cystic hygroma means water tumor. Lymphatic malformation is more commonly used now because it is a sponge-like collection of abnormal growth that contains clear lymphatic fluid. The fluid collects within the cysts or channels, usually in the soft tissue. Cystic hygromas occur when the lymphatic vessels that make up the lymphatic system are not formed properly. There are two types of lymphatic malformations. They are macrocystic lymphatic malformations, large cysts, and microcystic, small cysts. A person may have only one kind of the malformation or can have a mixture of both macro and micro cysts.

Cystic hygroma can be associated with a nuchal lymphangioma or a fetal hydrops. Additionally, it can be associated with Turner syndrome or with Noonan syndrome.

A lethal version of this condition is known as Cowchock Wapner Kurtz syndrome that, in addition to cystic hygroma, includes cleft palate and lymphedema, a condition of localized edema and tissue swelling caused by a compromised lymphatic system.

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.

Many conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment. The skin weighs an average of four kilograms, covers an area of two square meters, and is made of three distinct layers: the epidermis, dermis, and subcutaneous tissue. The two main types of human skin are: glabrous skin, the hairless skin on the palms and soles (also referred to as the "palmoplantar" surfaces), and hair-bearing skin. Within the latter type, the hairs occur in structures called pilosebaceous units, each with hair follicle, sebaceous gland, and associated arrector pili muscle. In the embryo, the epidermis, hair, and glands form from the ectoderm, which is chemically influenced by the underlying mesoderm that forms the dermis and subcutaneous tissues.

The epidermis is the most superficial layer of skin, a squamous epithelium with several strata: the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. Nourishment is provided to these layers by diffusion from the dermis, since the epidermis is without direct blood supply. The epidermis contains four cell types: keratinocytes, melanocytes, Langerhans cells, and Merkel cells. Of these, keratinocytes are the major component, constituting roughly 95 percent of the epidermis. This stratified squamous epithelium is maintained by cell division within the stratum basale, in which differentiating cells slowly displace outwards through the stratum spinosum to the stratum corneum, where cells are continually shed from the surface. In normal skin, the rate of production equals the rate of loss; about two weeks are needed for a cell to migrate from the basal cell layer to the top of the granular cell layer, and an additional two weeks to cross the stratum corneum.

The dermis is the layer of skin between the epidermis and subcutaneous tissue, and comprises two sections, the papillary dermis and the reticular dermis. The superficial papillary dermis with the overlying rete ridges of the epidermis, between which the two layers interact through the basement membrane zone. Structural components of the dermis are collagen, elastic fibers, and ground substance. Within these components are the pilosebaceous units, arrector pili muscles, and the eccrine and apocrine glands. The dermis contains two vascular networks that run parallel to the skin surface—one superficial and one deep plexus—which are connected by vertical communicating vessels. The function of blood vessels within the dermis is fourfold: to supply nutrition, to regulate temperature, to modulate inflammation, and to participate in wound healing.

The subcutaneous tissue is a layer of fat between the dermis and underlying fascia. This tissue may be further divided into two components, the actual fatty layer, or panniculus adiposus, and a deeper vestigial layer of muscle, the panniculus carnosus. The main cellular component of this tissue is the adipocyte, or fat cell. The structure of this tissue is composed of septal (i.e. linear strands) and lobular compartments, which differ in microscopic appearance. Functionally, the subcutaneous fat insulates the body, absorbs trauma, and serves as a reserve energy source.

Conditions of the human integumentary system constitute a broad spectrum of diseases, also known as dermatoses, as well as many nonpathologic states (like, in certain circumstances, melanonychia and racquet nails). While only a small number of skin diseases account for most visits to the physician, thousands of skin conditions have been described. Classification of these conditions often presents many nosological challenges, since underlying etiologies and pathogenetics are often not known. Therefore, most current textbooks present a classification based on location (for example, conditions of the mucous membrane), morphology (chronic blistering conditions), etiology (skin conditions resulting from physical factors), and so on. Clinically, the diagnosis of any particular skin condition is made by gathering pertinent information regarding the presenting skin lesion(s), including the location (such as arms, head, legs), symptoms (pruritus, pain), duration (acute or chronic), arrangement (solitary, generalized, annular, linear), morphology (macules, papules, vesicles), and color (red, blue, brown, black, white, yellow). Diagnosis of many conditions often also requires a skin biopsy which yields histologic information that can be correlated with the clinical presentation and any laboratory data.

Epidermal nevi, neoplasms, and cysts are skin lesions that develop from the epidermal layer of the skin.

- Aberrant basal cell carcinoma

- Acanthoma fissuratum (granuloma fissuratum, spectacle frame acanthoma)

- Acrospiroma (clear cell hidradenoma, dermal duct tumor, hidroacanthoma simplex, nodular hidradenoma, poroma)

- Actinic keratosis (senile keratosis, solar keratosis)

- Adenoid squamous cell carcinoma (pseudoglandular squamous cell carcinoma)

- Aggressive digital papillary adenocarcinoma (digital papillary adenocarcinoma, papillary adenoma)

- Apocrine gland carcinoma

- Apocrine nevus

- Arsenical keratosis

- Atrophic actinic keratosis

- Balanitis plasmacellularis (balanoposthitis chronica circumscripta plasmacellularis, balanitis circumscripta plasmacellularis, plasma cell balanitis, plasma cell vulvitis, vulvitis circumscripta plasmacellularis, Zoon's balanitis, Zoon's erythroplasia, Zoon's vulvitis)

- Basal cell carcinoma

- Basaloid follicular hamartoma

- Basaloid squamous cell carcinoma

- Birt–Hogg–Dubé syndrome

- Bowen's disease (squamous cell carcinoma "in situ")

- Brooke–Fordyce syndrome

- Ceruminoma

- Cicatricial basal cell carcinoma (morpheaform basal cell carcinoma, morphoeic basal cell carcinoma)

- Ciliated cyst of the vulva (cutaneous Müllerian cyst, paramesonephric mucinous cyst of the vulva)

- Clear cell acanthoma (acanthome cellules claires of Degos and Civatte, Degos acanthoma, pale cell acanthoma)

- Clear cell squamous cell carcinoma (clear cell carcinoma of the skin)

- Chronic scar keratosis (chronic cicatrix keratosis)

- Clonal seborrheic keratosis

- Common seborrheic keratosis (basal cell papilloma, solid seborrheic keratosis)

- Cowden syndrome (Cowden's disease, multiple hamartoma syndrome)

- Cutaneous ciliated cyst

- Cutaneous columnar cyst

- Cutaneous horn (Cornu cutaneum)

- Cystic basal cell carcinoma

- Dermal eccrine cylindroma (cylindroma)

- Dermatosis papulosa nigra

- Desmoplastic trichoepithelioma

- Dilated pore (dilated pore of Winer)

- Eccrine carcinoma (syringoid carcinoma)

- Eccrine nevus

- Epidermal cyst (epidermal inclusion cyst, epidermoid cyst, infundibular cyst, keratin cyst)

- Epidermal nevus syndrome (Feuerstein and Mims syndrome, Solomon's syndrome)

- Epidermolytic acanthoma

- Epithelioma cuniculatum (Ackerman tumor, carcinoma cuniculatum)

- Eruptive vellus hair cyst

- Erythroplasia of Queyrat

- Extramammary Paget's disease

- Fibroepithelioma

- Fibroepithelioma of Pinkus

- Fibrofolliculoma

- Follicular hybrid cyst (Hybrid cyst)

- Folliculosebaceous-apocrine hamartoma (follicular-apocrine hamartoma)

- Folliculosebaceous cystic hamartoma

- Generalized eruptive keratoacanthoma (generalized eruptive keratoacanthoma of Grzybowski)

- Giant solitary trichoepithelioma

- Hidradenoma

- Hidradenocarcinoma

- Hidrocystoma (cystadenoma, Moll's gland cyst, sudoriferous cyst)

- Hydrocarbon keratosis (pitch keratosis, tar keratosis, tar wart)

- Hyperkeratosis lenticularis perstans (Flegel's disease)

- Hyperkeratosis of the nipple and areola

- Hyperkeratotic actinic keratosis

- Ichthyosis hystrix (ichthyosis hystrix gravior type Lambert, porcupine man, systematized verrucous nevus)

- Ichthyosis hystrix of Curth–Macklin

- Infiltrative basal cell carcinoma

- Inflammatory linear verrucous epidermal nevus

- Inverted follicular keratosis

- Irritated seborrheic keratosis (basosquamous cell acanthoma, inflamed seborrheic keratosis)

- Isthmicoma (infundibuloma, tumor of the follicular infundibulum)

- Juvenile myelomonocytic leukemia

- Keratin implantation cyst

- Keratoacanthoma

- Keratoacanthoma centrifugum marginatum

- Large cell acanthoma

- Lichenoid actinic keratosis

- Lichenoid keratosis (benign lichenoid keratosis, lichen planus-like keratosis, solitary lichen planus, solitary lichenoid keratosis)

- Linear verrucous epidermal nevus (linear epidermal nevus, verrucous epidermal nevus)

- Malignant acrospiroma (malignant poroma, porocarcinoma, spiradenocarcinoma)

- Malignant mixed tumor (malignant chondroid syringoma)

- Malignant trichilemmal cyst

- Mantleoma

- Marjolin's ulcer

- Melanoacanthoma (pigmented seborrheic keratosis)

- Merkel cell carcinoma (cutaneous apudoma, primary neuroendocrine carcinoma of the skin, primary small cell carcinoma of the skin, trabecular carcinoma of the skin)

- Microcystic adnexal carcinoma (sclerosing sweat duct carcinoma)

- Micronodular basal cell carcinoma

- Milia en plaque

- Milium

- Mixed tumor (chondroid syringoma)

- Mucinous carcinoma

- Mucinous nevus (nevus mucinosus)

- Muir–Torre syndrome

- Multiple familial trichoepithelioma (Brooke–Spiegler syndrome, epithelioma adenoides cysticum)

- Multiple keratoacanthomas (Ferguson–Smith syndrome, Ferguson-Smith type of multiple self-healing keratoacanthomas, multiple keratoacanthomas of the Ferguson–Smith type)

- Multiple minute digitate hyperkeratosis (digitate keratoses, disseminated spiked hyperkeratosis, familial disseminated piliform hyperkeratosis, minute aggregate keratosis)

- Nevoid basal cell carcinoma syndrome (basal cell nevus syndrome, Gorlin syndrome, Gorlin–Goltz syndrome)

- Nevus comedonicus (comedo nevus)

- Nevus comedonicus syndrome

- Nevus sebaceous (nevus sebaceous of Jadassohn, organoid nevus)

- Nevus unius lateris

- Nodular basal cell carcinoma (classic basal cell carcinoma)

- Paget's disease of the breast

- Papillary eccrine adenoma (tubular apocrine adenoma)

- Papillary hidradenoma (hidradenoma papilliferum)

- Papillomatosis cutis carcinoides (Gottron's carcinoid papillomatosis, papillomatosis cutis carcinoides of Gottron–Eisenlohr)

- Patch blue nevus (acquired dermal melanocytosis, dermal melanocyte hamartoma)

- Perifollicular fibroma

- Phakomatosis pigmentokeratotica

- Pigmented actinic keratosis

- Pigmented basal cell carcinoma

- Pigmented hairy epidermal nevus syndrome

- Pilar sheath acanthoma

- Pilonidal sinus (Barber's interdigital pilonidal sinus, pilonidal cyst, pilonidal disease)

- Polypoid basal cell carcinoma

- Pore-like basal cell carcinoma

- Primary cutaneous adenoid cystic carcinoma

- Proliferating epidermoid cyst (proliferating epithelial cyst)

- Proliferating trichilemmal cyst (pilar tumor, proliferating follicular cystic neoplasm, proliferating pilar tumor, proliferating trichilemmal tumor)

- Pseudocyst of the auricle (auricular endochondrial pseudocyst, cystic chondromalacia, endochondral pseudocyst, intracartilaginous cyst)

- Pseudoepitheliomatous keratotic and micaceous balanitis

- PUVA keratosis

- Rasmussen syndrome

- Reactional keratosis

- Reticulated seborrheic keratosis (adenoid seborrheic keratosis)

- Rodent ulcer (Jacobi ulcer)

- Schimmelpenning syndrome (Schimmelpenning–Feuerstein–Mims syndrome)

- Sebaceoma (sebaceous epithelioma)

- Sebaceous adenoma

- Sebaceous carcinoma

- Sebaceous hyperplasia

- Sebaceous nevus syndrome

- Seboacanthoma

- Seborrheic keratosis (seborrheic verruca, senile wart)

- Seborrheic keratosis with squamous atypia

- Signet-ring cell squamous cell carcinoma

- Solitary keratoacanthoma (subungual keratoacanthoma)

- Solitary trichoepithelioma

- Spindle cell squamous cell carcinoma (spindle cell carcinoma)

- Spiradenoma

- Squamous cell carcinoma

- Steatocystoma multiplex (epidermal polycystic disease, sebocystomatosis)

- Steatocystoma simplex (simple sebaceous duct cyst, solitary steatocystoma)

- Stucco keratosis (digitate seborrheic keratosis, hyperkeratotic seborrheic keratosis, keratosis alba, serrated seborrheic keratosis, verrucous seborrheic keratosis)

- Superficial basal cell carcinoma (superficial multicentric basal cell carcinoma)

- Syringadenoma papilliferum (syringocystadenoma papilliferum)

- Syringofibroadenoma (acrosyringeal nevus of Weedon and Lewis)

- Syringoma

- Systematized epidermal nevus

- Thermal keratosis

- Trichilemmal carcinoma

- Trichilemmal cyst (isthmus-catagen cyst, pilar cyst)

- Trichilemmoma

- Trichoadenoma (trichoadenoma of Nikolowski)

- Trichoblastoma

- Trichoblastic fibroma

- Trichodiscoma

- Trichofolliculoma

- Unilateral palmoplantar verrucous nevus

- Urethral caruncle

- Verrucous carcinoma

- Verrucous cyst (cystic papilloma)

- Viral keratosis

- Warty dyskeratoma (isolated dyskeratosis follicularis)

- Waxy keratosis of childhood (kerinokeratosis papulosa)

- Zoon's vulvitis

- Zosteriform speckled lentiginous nevus