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, Zoons balanitis, Zoons erythroplasia, Zoons vulvitis)
Basal cell carcinoma
Basaloid follicular hamartoma
Basaloid squamous cell carcinoma
Birt–Hogg–Dubé syndrome
Bowens 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 (Cowdens 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, Solomons syndrome)
Epidermolytic acanthoma
Epithelioma cuniculatum (Ackerman tumor, carcinoma cuniculatum)
Eruptive vellus hair cyst
Erythroplasia of Queyrat
Extramammary Pagets 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, Molls gland cyst, sudoriferous cyst)
Hydrocarbon keratosis (pitch keratosis, tar keratosis, tar wart)
Hyperkeratosis lenticularis perstans (Flegels 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 (spiradenocarcinoma)
Malignant mixed tumor (malignant chondroid syringoma)
Malignant trichilemmal cyst
Mantleoma
Marjolins 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)
Pagets disease of the breast
Papillary eccrine adenoma (tubular apocrine adenoma)
Papillary hidradenoma (hidradenoma papilliferum)
Papillomatosis cutis carcinoides (Gottrons 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 (Barbers interdigital pilonidal sinus, pilonidal cyst, pilonidal disease)
Porocarcinoma (malignant poroma, eccrine porocarcinoma)
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)
Zoons vulvitis
Zosteriform speckled lentiginous nevus

Erythemas
Erythemas are reactive skin conditions in which there is blanchable redness.
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 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 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.