What causes elongated rete ridges?
What causes elongated rete ridges?
Elongation of the rete ridges and increased pigmentation in the basal cell region is present with transepidermal pigment cell excretion. Radiation lentigines show increased melanin deposition in basal keratinocytes, cellular or nuclear atypia, increased number of melanocytes, and reduction of rete ridges.
What is Psoriasiform hyperplasia?
A nonspecific, histologically defined appearance that consists of regular elongation of rete ridges, suprapapillary thinning, mild spongiosis, telangiectasis of blood vessels in the papillary dermis and fusion of foot processes.
What is acanthosis histology?
Acanthosis is a thickening of the epidermis and elongation of the rete ridges due to thickening of the spinous layer +/- enlargement of rete pegs. Typical examples include chronic eczematous reactions.
What is epidermal hyperplasia?
Synonyms: ‘hyperplastic epidermal layer’ Definition: increase in the number of normal cells in normal arrangement in the epidermis, typically resulting in increased thickness.
What is the function of rete ridges?
Abstract. In normal human skin, rete ridges play multiple roles in skin homeostasis. These interdigitations of the epidermis and dermis increase the contact area between these layers, enhancing adhesion. These distinct niches in skin also provide a specialized environment for keratinocyte stem cells.
Where do rete ridges form in the skin?
Rete ridges occur where the epidermis is thickest and extend deep into the dermis. Fibroblasts (yellow) are present throughout the dermis. Nerves and Schwann cells (light blue) are present in a complex arrangement throughout the dermis.
Is Psoriasiform dermatitis the same as psoriasis?
Psoriasiform dermatitis is a histological term that refers to a group of disorders which histologically mimic psoriasis. Chief among them in frequency are lichenified dermatitis, seborrheic dermatitis, and pityriasis rubra pilaris.
What is Spongiotic Psoriasiform dermatitis?
Psoriasiform spongiotic dermatitis, an inflammatory dermatosis, manifests from conditions like psoriasis, nutritional deficiencies and HIV.1 2 It distributes symmetrically on elbows, knees, scalp and torso,2 and excoriation of lesions leads to superinfection.
What is the difference between hyperkeratosis and acanthosis?
If the process becomes chronic, the edema regresses, and the epidermis becomes hyperplastic as a response to the chronic insult. Epidermal hyperplasia is seen as a thickening of the epidermis and elongation of the rete ridges (called acanthosis), accompanied by ortho or para-hyperkeratosis.
What is the difference between hyperplasia and neoplasia?
Hyperplasia is characterized by an increased number of cells but without modification of tissue organization. Neoplasia is a tissue neoformation linked to an excessive cell proliferation.
Where are rete ridges found?
Rete ridges surround the dermal papillae, which can be seen as small extensions protruding from the papillary dermis within the epidermis.