HISTOLOGICAL DIAGNOSTIC CLUES

Daniel J. Santa CruzSt Louis, MO, USA

PATHOGNOMONIC

(Gr. Pathos- disease + -Gnomonikos fit to give judgement)

1. Specifically distinctive or characteristic of a disease or pathological condition.

2. A sign or symptom on which a diagnosis can be made.

DORLAND’S Illustrated Medical Dictionary

BLUE CUTICLE IN THE HORNY LAYER

Scabies

Norwegian scabies

Scabies Demodex

ABSENCE OF EPIDERMAL GRANULAR CELL LAYER

Ichthyosis vulgaris

ICHTHYOSIS VULGARIS

ICHTHYOSIS VULGARIS

ICHTHYOSIS VULGARIS

ICHTHYOSIS NORMAL SKIN

GRANULAR PARAKERATOSIS

“Axillary” granular parakeratosis

Courtesy of Omar Sangueza, MD

CLINICAL FEATURES

Red or hyperpigmented areas in one or both axilla.

Also described in the submammary fold. Suspected to be a reaction to antiperspirants.

REFERENCES

Northcut AD, Nelson DM and Tschen JA. Axillary granular parakeratosis.J Am Acad Dermatol 1991; 24:541-4.

Barnes CJ, Lesher JL, and Sangueza OP. Axillary granular parakeratosis.Int J Dermatol 2001; 40:439-41

ALTERNATING ORTHO AND PARAKERATOSIS

Actinic keratosis

EPIDERMAL SQUAMOUS EDDIES

Incontinentia pigmenti

SQUAMOUS EDDIES

Irritated seborrheic keratosis Verrucae Squamous cell carcinoma Benign follicular neoplasms

THE VASE SIGN

Spongiotic dermatitis

SPONGIOTIC DERMATITIS

SPONGIOTIC DERMATITIS

CD1a

Mycosis fungoides Langerhans cell histiocytosis

Spongiotic folliculitis

LeBoit, P E and Epstein, B AA vase-like shape characterizes the epidermal-mononuclear cell collections seen in spongiotic dermatitis.Am J Dermatopathol 1990, 12: 612-6

GRANULAR KERATINOCYTIC NECROSIS

Herpetic infection

HERPES

HERPES

HERPES

HERPES

HERPES

EPIDERMAL DYSTROPHY

Chemotherapy effect

EPIDERMAL DYSTROPHY

Pronounced dysmaturation of the epidermis Keratinocytes with large nuclei alternating with

very small ones Multiple nucleoli Apoptosis at all levels of the epidermis High level mitoses Abnormal mitoses

EPIDERMAL DYSTROPHYDifferential diagnosis

Carcinoma in situ Actinic keratosis Erythema ab igne Viral cytopathic effect Post radiation changes

BASEMENT MEMBRANE THICKENING

Discoid lupus erythematosus

DISCOID LUPUS ERYTHEMATOSUS

DISCOID LUPUS ERYTHEMATOSUS

DISCOID LUPUS ERYTHEMATOSUS

DISCOID LUPUS ERYTHEMATOSUS

PAS

DISCOID LUPUS ERYTHEMATOSUS

Ig G

THICKENING OF THE BASEMENT MEMBRANE

Although very characteristic of DLE, basement membrane tickening can be see in: Inflammed seborrheic keratosis Lichen sclerosus et atrophicus

CATERPILLAR BODIES

Porphyria cutanea tarda

CATERPILLAR BODIES

CATERPILLAR BODIES

PAS

PAS

Egbert, B M, LeBoit, P E, McCalmont, T, Hu, C H and Austin, CCaterpillar bodies: distinctive, basement membrane-containing structures in blisters of porphyria.Am J Dermatopathol 1993, 15: 199-202

PUNCHED OUT HOLES IN SEBACEOUS GLANDS

Nevus sebaceus of Jadasshon

NEVUS SEBACEUS

NEVUS SEBACEUS

Wilson Jones, E and Heyl, TNaevus sebaceus. A report of 140 cases with special regard to the development of secondary malignant tumours.Br J Dermatol 1970, 82: 99-117

PAPILLARY MESENCHYMAL BODIES

Tumors of the hair germ

TRICHOEPITHELIOMA

TRICHOEPITHELIOMA

FOLLICULAR BULB AND PAPILLA

ADULT ANAGEN

TRICHOBLASTOMA

PAPILLARY MESENCHYMAL BODIES

Brooke, J D,Fitzpatrick, J E and Golitz, L EPapillary mesenchymal bodies: a histologic finding useful in differentiating trichoepitheliomas from basal cell carcinomas.J Am Acad Dermatol 1989, 21: 523-8

TRICHOMALACIA

Traction alopecia

TRACTION ALOPECIA

TRACTION ALOPECIA

TRACTION ALOPECIA

CHOLESTEROL CRYSTALS IN DERMAL ARTERIES

Atheromatous emboli

ATHEROMATOUS EMBOLI

ATHEROMATOUS EMBOLI

Malakoplakia

MICHAELIS-GUTMAN BODIES

MALAKOPLAKIA

MALAKOPLAKIA

MALAKOPLAKIA

PAS Von Kossa