A Notebook of Dermatopathology

Mastering the Basics, Pattern Recognition, and Key Pathologic Findings

Mariya Miteva

• Publisher: CRC Press
• Year: 2016
• Print ISBN:
  9781138704084
• eBook ISBN:
  9781315341354
• Topic: Medicine
• Subtopic: Dermatology

This is an invaluable collection of information designed to help residents, fellows, and students - as well as any already qualified medical professional interested in revising the essentials of skin conditions – to master the basics of skin pathology. Using the principle of pattern recognition, it simplifies the multitude of dermatopathologic signs by using easy-to-memorize images of what the key features look like - photomnemonics. There are also helpful sections on the technical aspects of dermatopathology and on the key findings at each level of the skin. Organized simply and abundantly illustrated, this text will be an indispensable guide to revision for all its readers.

SECTION II: MOST COMMON DERMATOLOGIC DISORDERS: PATTERN ANALYSIS

3	Inflammatory dermatoses

SPONGIOTIC PATTERN

Mariya Miteva and Jacquelyn Dosal

Definition: Presence of inter- and intracellular edema (spongiosis) in the epidermis. Intercellular edema results in widening of the spaces between cells, which elongates their intercellular bridges.

(Figure 3.1)

General concepts

NB Spongiosis is a dynamic process – findings depend on the stage of evolution: with time, all spongiotic dermatitides become more psoriasiform and less spongiotic.

(Table 3.1, Figure 3.2)

• In the subacute and chronic stage (when the epidermis has had time to respond to the inflammatory injury), spongiosis often has a parakeratotic cap and a diminished granular layer.

• Inflammatory cells are common at sites of spongiosis (lymphocytes and occasional eosinophils and Langerhans cells) and in perivascular distribution in the superficial dermis (lymphocytes and occasional eosinophils).

Table 3.1 Comparison of acute, subacute, and chronic spongiotic dermatitis

Phase	Histologic features
Acute	Normal stratum corneum
(Prototype: allergic contact dermatitis)	Marked spongiosis (vesicles)
	No acanthosis
Subacute	Parakeratosis
(Prototype: nummular eczema)	Mild spongiosis Variable hypogranulosis Acanthosis Superficial perivascular infiltrate in the dermis
Chronic (Prototype: lichen simplex chronicus)	Compact hyperkeratosis, variable parakeratosis Spongiosis may be subtle Hypergranulosis Psoriasiform acanthosis Superficial perivascular infiltrate Variable papillary dermal fibrosis

NB Exocytosis should be distinguished from epidermotropism.

• The shape of the spongiotic vesicle has been resembled to a small turned vase with peppered lymphocytes versus a circle with fewer malignant lymphocytes in Pautrier’s microabscess.

NB The vase can sometimes be upright.

(Figure 3.3)

• Ballooning degeneration: Keratinocytes swell like a balloon and the nucleus is pushed off to the side. Severe ballooning degeneration results in reticular degeneration: multilocular balloons explode, leaving behind fragments of cells on background of and intercellular irregular “messy” edema.

NB The differential diagnosis for this pattern is between irritant contact dermatitis and viral exanthem.

(Figure 3.4)

• Pronounced spongiosis may lead to edema in the papillary dermis.

NB Differential diagnosis of papillary dermal edema includes arthropod bite reaction, Sweet’s syndrome, allergic contact dermatitis, erythema multiforme, pernio, polymorphic light eruption.

• Spongiotic mimickers:

– Clear cells due to glycogen (outer root sheath of the follicular epithelium, clear cell acanthoma)

– Pagetoid cells (pagetoid melanoma, Bowen’s disease, Paget’s disease; metastatic carcinomas)

– Pallor of the epidermis (in its upper parts) – nutritional and enzymatic deficiencies (necrolytic migratory erythema, acrodermatitis enteropathica, pellagra)

• For the overlap of spongiosis with other inflammatory patterns, see Figure 3.5.

(Figure 3.5)

On low power

(Photomnemonic 3.1)

• Pale and spongy epidermis with various degrees of intercellular edema: mild spongiosis in subacute spongiotic dermatitis; moderate with vesicles in acute spongiotic dermatitis; severe in reticular degeneration in irritant contact dermatitis and viral rash

• Hyperkeratosis or parakeratosis with/without a serum crust (coagulated plasma)

• Variable acanthosis

(Table 3.2)

On high power

Atopic dermatitis

Atopic dermatitis can present as acute, subacute or chronic spongiotic dermatitis.

Table 3.2 Spongiotic disorders classified by the type of predominant cell in the infiltrate

Additional features:

• Hyperkeratosis of the acrosyringium: a cap of hyperkeratosis on top of acrosyringium (atopic patients worsen with sweating) (Figure 3.6)

Seborrheic dermatitis

• Ortho/hyperkeratotic stratum corneum with shoulder...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Preface
• Acknowledgments
• SECTION I: THE BASICS OF DERMATOPATHOLOGY
• SECTION II: MOST COMMON DERMATOLOGIC DISORDERS: PATTERN ANALYSIS
• SECTION III: “SPLIT SKIN”: KEY PATHOLOGIC FINDINGS