Dermatology Practical & Conceptual

Spitz and Reed nevi: acquired or congenital?

…te melanocytes are an expected finding in congenital type nevi like Unna or Miescher nevi, but virtually never seen in acquired nevi like Clark’s [1]. Thus, the occurrence of large and multinucleate melanocytes in about 25% of the lesions analy…

Histologic Diagnosis of Inflammatory Skin Diseases

Sebaceous Units

…nds do not become noticeably smaller as the turnover of mature sebocytes decreases. In conclusion, the amount and rate of sebaceous secretion are governed by the action of androgens on immature sebocytes. Sebum is not known to have any role physiolog…

Histologic Diagnosis of Inflammatory Skin Diseases

Mycosis fungoides

…ify manifestations clinical of lichen planus with designations like hypertrophic and atrophic, so, too, it is with terms like “large-plaque parapsoriasis,” “small plaque parapsoriasis,” and “alopecia mucinosa” for…

Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Skin: Perivascular Dermatitis

See Figs. 5.16 A&B, 5.17 A&B, 5.18 A&B, 5.19 A&B, 5.20 A&B, 5.21 A&B, and 5.22 A&B Figure 5.16 A. Perivascular dermatitis, perivascular only, superficial. B. Perivascular dermatitis, perivascular only, superficial and…

Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Subcutaneous Fat: Panniculitis

See Fig. 5.385 A-C. Figure 5.385 Patterns of panniculitis. A. Septal mostly. B. Lobular mostly. C. Septal and lobular “equally.” At scanning magnification, the normal subcutaneous fat is seen to be segregated by struts of fibrous tiss…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

Images 10.63.1A: Perivascular dermatitis, interface, vacuolar + 10.63.1B: Smudged appearance of the dermoepidermal junction, focally thinned epidermis, and plentiful mucin throughout the dermis = Lupus erythematosus, discoid ┬áThe presence…

Differential Diagnosis in Dermatopathology

Discussions

The effects of products of dense, often bandlike infiltrates of lymphocytes can drive both lichen planus-like keratosis and primary cutaneous melanoma into regression, i.e., involution (as they can the type of melanocytic nevus picturesquely termed…

Histologic Diagnosis of Inflammatory Skin Diseases

Melanocytes

Melanocytes synthesize melanin. From precursors in the neural crest, melanocytes migrate normally to the epidermis, the bulb of hair follicles, epithelia of various mucous membranes, leptomeninges, inner ear, and a few other tissues (Fig. 1.61). Pri…

Histologic Diagnosis of Inflammatory Skin Diseases

Subcutaneous T-cell lymphoma

Subcutaneous T-cell lymphoma Synonyms Subcutaneous panniculitis-like lymphoma Presentation stereotypical Age and sex Mostly women in the third and fourth decades of life Distribution of lesions Extremities, trunk, face, neck, and breasts Arrangement…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Eczema?

“Eczema is that which looks like eczema.” Hebra F. Kaposi M. Lehrbuch der Hautkrankheiten. Bd, 2. Aufl. Erlangen: Enke, 1874:403-93. “In Anglo-American usage, the term dermatitis is being used increasingly for all these conditi…