Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Subcutaneous Fat: Panniculitis

…, such as granuloma annulare, may be situated in the reticular dermis alone (Fig. 5.393 A&B), in both that part of the dermis and the subcutaneous fat together (Fig. 5.394 A&B), or in the panniculus adiposa alone (“subcutaneous granulom…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…form lichenoid + 11.14.1B: Lymphocytes, sparse in both the dermis and epidermis, larger in the epidermis than in dermis, solitary in the basal layer in foci, and in association with scant spongiosis in the spinous zone = Mycosis fungoides, patch…

Histologic Diagnosis of Inflammatory Skin Diseases

Embryologic Development

…s. Early in embryogenesis, the interface between epidermis and dermis is flat. During the first trimester, a basement membrane, synthesized mostly by epidermal basal cells, forms at the junction of dermis and epidermis. Around the second trimester, t…

Histologic Diagnosis of Inflammatory Skin Diseases

Introduction

…attributes being typical of an epithelium, in contrast to the dermis, which consists mostly of relatively noncellular connective tissue composed of collagen bundles, elastic fibers, and ground substance, characteristic of a nonepithelium. The dermis

Histologic Diagnosis of Inflammatory Skin Diseases

Fixed drug eruption

…filtrate of lymphocytes Numerous melanophages in the papillary dermis; if a lesion occurred there previously, and especially several times, melanophages may be situated at the base of the papillary dermis and even in the upper part of the reticular d…

Histologic Diagnosis of Inflammatory Skin Diseases

Lichen planus

…of lymphocytes that also forms a band in a thickened papillary dermis and across the upper part of the reticular dermis, and obscures the junction of an acanthotic, somewhat jagged, surface epidermis. The surface of the lesion is flat because the sur…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…sinophils in conjunction with extensive edema of the papillary dermis = Response to an insect “bite” Striking edema of the papillary dermis may be encountered both in urticarial papules and in papulovesicles brought into being by the &#82…

Histologic Diagnosis of Inflammatory Skin Diseases

Lupus erythematosus

…present in the interstitium of the upper part of the reticular dermis, at times becoming dense there Rarely, neutrophils also may be present in patchy distribution in the lower half of the reticular dermis Early Lymphocytes around venules of the su…

Histologic Diagnosis of Inflammatory Skin Diseases

Livedo vasculitis

…ibrin thrombi in the lumen of venules in the upper part of the dermis mostly; sometimes, the lower half of the dermis is affected and, episodically, the subcutaneous fat Numerous erythrocytes extravasated in the upper part of the dermis Fully develo…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Blue Nevus?

…aying of melanocytes mostly in the upper half of the reticular dermis Mark’s nevus Deep congenital nevus characterized by diffuse infiltrates of melanocytes throughout the reticular dermis and in the subcutaneous fat (“giant nevi,&#8221…