Chronic superficial dermatitis Clinical features Chronic superficial dermatitis (digitate dermatosis, superficial scaly dermatitis, small-plaque parapsoriasis, persistent superficial dermatitis) is a not uncommon condition, which presents as erythematous scaly persistent patches, showing a predilection for the limbs and trunk. While the…
The term ‘lichenoid’ refers to inflammatory dermatoses which are characterized by a bandlike lymphohistiocytic infiltrate in the upper dermis, hugging and often obscuring the dermal–epidermal interface. Lichen planus is the prototypic lichenoid dermatitis ( Box 7.1 ). Interface dermatitis refers…
Eczematous Dermatitis This chapter discusses a number of disorders under the rubric eczematous dermatitis, also called eczema and spongiotic dermatitis. The term eczema refers to a group of disorders that share similar clinical and histologic features but may have different…
Introduction The term acantholysis derives from the Greek akantha , a thorn or prickle, and lysis , a loosening. In its simplest definition, the term is used to reflect a primary disorder of the skin (and sometimes the mucous membranes)…
Blisters, which are clinically subdivided into vesicles (L. vesicula , dim. of vesica , bladder) and bullae (L. bubble), are defined as accumulations of fluid either within or below the epidermis and mucous membranes. Although somewhat arbitrary, the term ‘vesicle’…
Ichthyosis The term ichthyosis (Gr. ichthys , fish) is applied to a number of heterogeneous genetic disorders characterized by permanent and generalized abnormal keratinization. The clinical features range from mild involvement, often passed off as ‘dry skin’ (xerosis), through to…
Specimen fixation, grossing/put-through, processing, embedding and sectioning The aim of fixation is to maintain clear and consistent lesional features and to preserve tissue in an optimal state suitable for a range of staining and ancillary histopathological techniques. Most fixation methods…
Introduction Skin is a double-layered membrane covering the exterior of the body and consists of a stratified cellular epidermis and an underlying dermis of connective tissue. In adults, the skin weighs over 5 kg and covers a surface area approaching 2 m…
Thyroid Resection Thyroid surgery is usually performed to remove solitary nodules (benign or malignant), multinodular goiters, or, rarely, for the treatment of Graves’ disease. Thyroid resection specimens include total thyroidectomies, near-total thyroidectomies, hemithyroidectomies, lobectomies, and isthmusectomies. Many nodules will have…
The thymus may be removed due to disease (both benign and malignant tumors), for the treatment of myasthenia gravis, or, rarely, incidentally during thoracic surgery (e.g., open heart surgery). If the specimen is of an anterior mediastinal mass, one must…