Search Results for: dermis

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Blue Nevus?

…olar and dendritic melanocytes lie singly or in masses in the dermis. . . . The cellular type is composed of the same elements as the ordinary type, but in addition possesses islands of larger cells arranged in a neuroid (‘pigmented neurofibrom…

Histologic Diagnosis of Inflammatory Skin Diseases

Polymorphous light eruption

…cular infiltrate of lymphocytes Marked edema of the papillary dermis Subepidermal vesiculation secondary to edema of the papillary dermis occurs uncommonly; epidermis usually tethered to the dermis by gossamer strands of collagen Spongiosis of variab…

Histologic Diagnosis of Inflammatory Skin Diseases

Blood Vessels

…es and venules is situated in the lower part of the reticular dermis, and the superficial plexus is positioned in the upper part of the reticular dermis, just beneath the papillary dermis. In times past, the superficial plexus was called the “s…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Radial Growth Phase versus Vertical Growth Phase of Melanoma?

…l growth phase is the incapacity to form tumor nodules in the dermis. Thus the radial growth phase may also be called nontumorigenic. . . . The vertical growth phase is, by definition, the appearance of a population of cells within the primary neopla…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…period of time. The alterations are confined mostly to the epidermis and thickened papillary dermis. 10.23.2A: Perivascular dermatitis, psoriasiform, markedly hyperkeratotic + 10.23.2B: Orthokeratosis, hypergranulosis, acanthosis, proliferation of in…

Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Skin: Nodular and Diffuse Dermatitis

…are centered around venules, usually throughout the reticular dermis (Fig. 5.175 A&B), but sometimes also in septa of the subcutaneous fat and at other times restricted to the upper part of the dermis (Fig. 5.176 A&B). Very often, endothelial…

Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Skin: Vesicular Dermatitis

…skin and, in most of them, are situated either within the epidermis (intraepidermal) (see Fig. 5.239A) or beneath the epidermis (subepidermal) (see Fig. 5.239B). Sometimes, however, a blister is seen to be in both intra- and subepidermal locales, co…

Histologic Diagnosis of Inflammatory Skin Diseases

Arthropod assaults

…dy response to mouthparts of a tick embedded in the reticular dermis. Blister beetle dermatitis is produced by beetles of the family Meloidae, the most famous of them being Lytta vesicatoria (“Spanish fly”) that produces an oil, cantharid…

Histologic Diagnosis of Inflammatory Skin Diseases

Errors and Reasons

…one. Reason: In fact, loss of elastic tissue in the reticular dermis especially, but also of some collagen, is responsible for anetoderma. Error: Apoptosis is not necrosis. Reason: In classic Virchowian pathology, necrosis is characterized cytopathol…