Differential Diagnosis in Dermatopathology

Xanthogranuloma vs. Reticulohistiocytic granuloma

A malignant neoplasm of melanocytes that, in the skin, begins as a macule and may become a patch or a papule. A flat lesion of melanoma tends to be asymmetrical, poorly circumscribed with a scalloped, jagged, or notched border, and variegate, mostly…

Differential Diagnosis in Dermatopathology

Discussions

…ate when they are rubbed, a phenomenon known as Darier’s sign. A solitary lesion of juvenile xanthogranuloma may be confused clinically with a Spitz’s nevus. Each may be an orange, smooth-surfaced papule. In contrast to the expression in…

Histologic Diagnosis of Inflammatory Skin Diseases

Scar

Scar Synonyms Cicatrix Presentation stereotypical Age and sex Any age and both sexes Distribution of lesions Usually localized, but sometimes widespread Configuration of lesions Linear, as in a surgical wound Round, as a consequence of an ulcer ind…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Benign and Malignant Cells?

…or cells, benign or malignant, growing in vitro usually do not show any structural features that are pathognomonic of neoplasia.” Diamandopoulos GT. Neoplasia. In: Kissane JM, ed. Anderson’s Pathology. 8th ed. St. Louis, MO: CV Mosby Co….

Differential Diagnosis in Dermatopathology

Differential Diagnosis

Spitz’s Nevus, Compound Type Melanoma 1. Symmetric 1. Asymmetric 2. Sharp circumscription 2. Poor circumscription 3. Maturation of melanocytes (decrease in size of aggregations and of nuclei) with descent progressive 3. No maturation w…

Differential Diagnosis in Dermatopathology

Images

Dermatofibroma Desmoplastic Spitz’s nevus

Differential Diagnosis in Dermatopathology

Differential Diagnosis

Dermatofibroma Desmoplastic Spitz’s nevus 1. Acanthotic epidermis often associated with induction of folliculo-sebaceous units 1. Little or no acanthosis; no induction of folliculo-sebaceous units 2. Epidermis often thinned above the cen…

Histologic Diagnosis of Inflammatory Skin Diseases

Dermatofibroma

…absence of trauma. Desmoplastic melanoma is more asymmetrical, subtly variegate in color, and unaffiliated with a “dimple sign.” Spitz’s nevus may be red, orange, or pink, as well as brown or black, but it is not firm unless it is w…

Differential Diagnosis in Dermatopathology

Images

Spitz’s Nevus, Compound Type Melanoma…

Histologic Diagnosis of Inflammatory Skin Diseases

Lymphadenosis benigna cutis

…cal Lymphoma may be indistinguishable. When the breast is the site affected, primary carcinoma must be considered. Tick “bite” and assaults by other arthropods may be identical. Spitz’s nevus often presents itself as a pink, red, o…