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List Of Cutaneous (Skin) Conditions - Dermal and Subcutaneous Growths
There are many conditions of or affecting the human integumentary system—the organ system that covers the entire surface of the body and is 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. There are two main types of human skin: glabrous skin, the non-hairy skin on the palms and soles (also referred to as the "palmoplantar" surfaces), and hair-bearing skin. Within the latter type, there are hairs 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 via diffusion from the dermis, since the epidermis is without direct blood supply. The epidermis contains four cell types: keratinocytes, melanocytes, Langerhans cells, and the Merkel cell. 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; it takes about two weeks 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 and reticular dermis. The superficial papillary dermis interdigitates 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 extrafibrillar matrix (previously called 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 colour (red, blue, brown, black, white, yellow). The diagnosis of a many conditions often also requires a skin biopsy which yields histologic information that can be correlated with the clinical presentation and any laboratory data.
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Diseases – Cutaneous (Skin) Diseases – Dermal and Subcutaneous Growths
Dermal and subcutaneous growths result from (1) reactive or neoplastic proliferation of cellular components of the dermis or subcutaneous tissue, or (2) neoplasms invading or aberrantly present in the dermis.
- Acquired progressive lymphangioma (Benign lymphangioendothelioma)
- Acral arteriolar ectasia
- Acral fibrokeratoma (Acquired digital fibrokeratoma, Acquired periungual fibrokeratoma)
- Acrochordon (Cutaneous papilloma, Cutaneous tag, Fibroepithelial polyp, Fibroma molluscum, Fibroma pendulum, Papilloma colli, Skin tag, Soft fibroma, Templeton skin tag)
- Adenoma sebaceum
- Adult type of generalized eruption of cutaneous mastocytosis
- African cutaneous Kaposi sarcoma
- African lymphadenopathic Kaposi sarcoma
- Aggressive infantile fibromatosis
- AIDS-associated Kaposi sarcoma
- Ainhum (Bankokerend, Dactylolysis spontanea, Sukhapakla)
- Angiofibroma
- Angiokeratoma
- Angiokeratoma of Mibelli (Mibelli's angiokeratoma, Telangiectatic warts)
- Angioleiomyoma (Vascular leiomyoma)
- Angiolipoleiomyoma
- Angiolipoma
- Angioma serpiginosum
- Angiosarcoma
- Aponeurotic fibroma (Calcifying aponeurotic fibroma, Juvenile aponeurotic fibroma)
- Atypical fibroxanthoma
- Benign lipoblastomatosis (Embryonic lipoma)
- Buschke–Ollendorff syndrome (Dermatofibrosis lenticularis disseminata)
- Capillary aneurysms
- Carcinoid
- Cherry angioma (De Morgan spot, Senile angioma)
- Chondrodermatitis nodularis chronica helicis (Chondrodermatitis nodularis helicis)
- Chondroid lipoma
- Chordoma
- Classic Kaposi sarcoma
- Collagenous fibroma (Desmoplastic fibroblastoma)
- Composite hemangioendothelioma
- Connective tissue nevus (Collagenoma, Elastoma, Shagreen patch)
- Cutaneous endometriosis
- Cutaneous meningioma (Heterotopic meningeal tissue, Rudimentary meningocele)
- Cutaneous myelofibrosis
- Cutaneous myxoma
- Cutis marmorata telangiectatica congenita (Congenital generalized phlebectasia, Van Lohuizen syndrome)
- Dermal dendrocyte hamartoma
- Dermatofibroma (Benign fibrous histiocytoma, Dermal dendrocytoma, Fibrous dermatofibroma, Fibrous histiocytoma, Fibroma simplex, Histiocytoma, Nodular subepidermal fibrosis, Sclerosing hemangioma)
- Dermatofibrosarcoma protuberans
- Desmoid tumor
- Diffuse cutaneous mastocytosis
- Diffuse infantile fibromatosis
- Dupuytren's contracture (Dupuytren's diathesis, Dupuytren's disease, Palmar fibromatosis)
- Eccrine angiomatous hamartoma
- Elastofibroma dorsi
- Endovascular papillary angioendothelioma (Dabska tumor, Dabska-type hemangioendothelioma, Hobnail hemangioendothelioma, Malignant endovascular papillary angioendothelioma, Papillary intralymphatic angioendothelioma)
- Epithelioid hemangioendothelioma
- Epithelioid sarcoma
- Erythrodermic mastocytosis
- Extraskeletal chondroma (Chondroma of soft parts)
- Familial myxovascular fibromas
- Fascial hernia
- Fibroma of tendon sheath
- Fibromatosis colli (Sternomastoid tumor of infancy)
- Fibrous hamartoma of infancy
- Fibrous papule of the nose (Benign solitary fibrous papule, Fibrous papule of the face)
- Folded skin with scarring (Michelin tire baby syndrome)
- Fordyce's spot (Angiokeratoma of Fordyce, Angiokeratoma of the scrotum and vulva, Fordyce's disease)
- Ganglion cyst
- Ganglioneuroma
- Genital leiomyoma (Dartoic leiomyoma)
- Giant cell tumor of the tendon sheath (Giant cell synovioma, Localized nodular tenosynovitis, Pigmented villonodular synovitis)
- Glomeruloid hemangioma
- Glomus tumor (Glomangioma)
- Granular cell tumor (Abrikossoff's tumor, Abrikossov's tumor, Granular cell myoblastoma, Granular cell nerve sheath tumor, Granular cell schwannoma)
- Hamartoma
- Hemangiopericytoma
- Hemangiosarcoma
- Hibernoma (Fetal lipoma, Lipoma of embryonic fat, Lipoma of immature adipose tissue)
- Hypertrophic scar
- Immunosuppression-associated Kaposi sarcoma
- Infantile digital fibromatosis (Inclusion body fibromatosis, Infantile digital myofibroblastoma, Reye tumor)
- Infantile hemangiopericytoma (Congenital hemangiopericytoma)
- Infantile myofibromatosis (Congenital generalized fibromatosis, Congenital multicentric fibromatosis)
- Infantile systemic hyalinosis (Juvenile systemic hyalinosis)
- Intradermal spindle cell lipoma
- Intravascular papillary endothelial hyperplasia (Masson's hemangio-endotheliome vegetant intravasculaire, Masson's lesion, Masson's pseudoangiosarcoma, Masson's tumor, Papillary endothelial hyperplasia)
- Juvenile hyaline fibromatosis (Fibromatosis hyalinica multiplex juvenilis, Murray–Puretic–Drescher syndrome)
- Kaposiform hemangioendothelioma (Infantile kaposiform hemangioendothelioma)
- Kasabach–Merritt syndrome (Hemangioma with thrombocytopenia)
- Keloid (Keloidal scar)
- Keratinizing metaplasia
- Keratocyst
- Klippel–Trenaunay syndrome (Angioosteohypertrophy syndrome, Hemangiectatic hypertrophy)
- Knuckle pads (Heloderma)
- Leiomyosarcoma
- Lipoma
- Liposarcoma (Atypical lipoma, Atypical lipomatous tumor)
- Lymphangiectasis (Lymphangioma)
- Lymphangiomatosis
- Malignant fibrous histiocytoma
- Malignant peripheral nerve sheath tumor (Malignant schwannoma, Neurofibrosarcoma, Neurosarcoma)
- Mast cell sarcoma
- Meningocele
- Metastatic carcinoma
- Microvenular hemangioma (Microcapillary hemangioma)
- Midline nevus flammeus (Angel's kiss, Salmon patch)
- Multifocal lymphangioendotheliomatosis (Congenital cutaneovisceral angiomatosis with thrombocytopenia, Multifocal Lymphangioendotheliomatosis with thrombocytopenia)
- Multinucleate cell angiohistocytoma
- Multiple cutaneous and uterine leiomyomatosis syndrome (Leiomyomatosis cutis et uteri, Multiple leiomyomatosis, Reed's syndrome)
- Multiple cutaneous leiomyoma (Pilar leiomyoma)
- Neural fibrolipoma
- Neuroblastoma (Infantile neuroblastoma, Neuroepithelioma)
- Neuroma cutis
- Neurothekeoma (Bizarre cutaneous neurofibroma, Cutaneous lobular neuromyxoma, Myxoma of the nerve sheath, Myxomatous perineurioma, Nerve sheath myxoma)
- Nevus anemicus
- Nevus flammeus (Capillary malformation, Port-wine stain)
- Nevus flammeus nuchae (Stork bite)
- Nevus lipomatosus superficialis (Nevus lipomatosis of Hoffman and Zurhelle)
- Nevus oligemicus
- Nodular fasciitis (Nodular pseudosarcomatous fasciits, Pseudosarcomatous fasciitis, Subcutaneous pseudosarcomatous fibromatosis)
- Oral submucous fibrosis
- Pachydermodactyly
- Palisaded encapsulated neuroma
- Paraneoplastic syndrome
- Pearly penile papules (Hirsuties coronae glandis, Hirsutoid papillomas)
- Peyronie's disease (Induratio penis plastica)
- Phakomatosis pigmentovascularis
- Piloleiomyoma
- Plantar fibromatosis (Ledderhose's disease)
- Pleomorphic fibroma
- Pleomorphic lipoma
- Plexiform fibrohistiocytic tumor
- Porokeratotic eccrine ostial and dermal duct nevus
- Progressive nodular histiocytoma
- Proliferating angioendotheliomatosis
- Prominent inferior labial artery
- Pseudo-ainhum
- Retiform hemangioendothelioma (Hobnail hemangioendothelioma)
- Schwannoma (Acoustic neuroma, Neurilemmoma, Neurinoma, Neurolemmoma, Schwann cell tumor)
- Solitary angiokeratoma
- Solitary cutaneous leiomyoma
- Solitary mastocytoma
- Solitary neurofibroma (Plexiform neurofibroma, Solitary nerve sheath tumor, Sporadic neurofibroma)
- Spider angioma (Nevus araneus, Spider telangiectasia, Spider nevus, Vascular spider)
- Spindle cell hemangioendothelioma (Spindle cell hemangioma)
- Spindle cell lipoma
- Sternal cleft
- Subungual exostosis
- Superficial acral fibromyxoma
- Systemic mastocytosis
- Targetoid hemosiderotic hemangioma (Hobnail hemangioma)
- Telangiectasia
- Telangiectasia macularis eruptiva perstans
- Teratoma
- Tufted angioma (Acquired tufted angioma, Angioblastoma, Angioblastoma of Nakagawa, Hypertrophic hemangioma, Progressive capillary hemangioma, Tufted hemangioma)
- Umbilical granuloma
- Universal angiomatosis (Generalized telangiectasia)
- Urticaria pigmentosa (Childhood type of generalized eruption of cutaneous mastocytosis)
- Venous lake (Phlebectases)
- Wildervanck syndrome
- Xanthelasmoidal mastocytosis
- Zosteriform metastasis
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