Differential Diagnosis in Dermatopathology

Papular mucinosis vs Interstitial granuloma annulare

An inflammatory process that develops secondary to trauma, usually in the form of a penetrating injury or rupture of a follicle, and that proceeds through stages of granulation tissue with numerous extravasated erythrocytes, granulomatous inflammati…

Differential Diagnosis in Dermatopathology

Discussions

Granuloma annulare and necrobiosis lipoidica are characterized by palisaded (and sometimes interstitial) granulomatous dermatitis, associated with superficial and deep perivascular infiltrates of mononuclear cells, and some degeneration of bundles o…

Dermatology Practical & Conceptual

Multiple primary thick melanomas: similar dermoscopic pattern

It has been observed that a patient’s “normal” moles resemble each other clinically. This concept also applies to dermoscopic observations, as shown by our previous demonstration that an individual’s nevi tend to have one to three predom…

Differential Diagnosis in Dermatopathology

Discussions

As their names denote, herpes simplex is caused by a herpesvirus and cowpox (vaccinia) by a poxvirus. Both are DNA viruses that induce lesions in the skin that share many findings histopathologic, e.g., intraepidermal vesicles surrounded by balloone…

Differential Diagnosis in Dermatopathology

Herpes simplex vs. Vaccinia

An inflammatory process that develops secondary to trauma, usually in the form of a penetrating injury or rupture of a follicle, and that proceeds through stages of granulation tissue with numerous extravasated erythrocytes, granulomatous inflammati…

Differential Diagnosis in Dermatopathology

Differential Diagnosis

Sebaceous hyperplasia Nevus sebaceus of Jadassohn 1. Dome-shaped papule with a central cell 1. Relatively flat-topped plaque in early stage; papillated or digitated plaque in fully developed and later stages; no dell 2. Basket-woven pattern of…

Differential Diagnosis in Dermatopathology

Discussions

Both sebaceous hyperplasia and nevus sebaceus of Jadassohn consist of abnormalities of sebaceous glands but the former, as the name denotes, is a hyperplasia, whereas the latter is a hamartoma that involves not only sebaceous units, but other adnexa…

Differential Diagnosis in Dermatopathology

Discussions

Trichoblastoma is the name generic for all benign neoplasms composed of trichoblasts and trichoblastic carcinoma is the term generic for all malignant neoplasms made up of trichoblasts. A synonym for trichoblastic carcinoma is basal-cell carcinoma….

Differential Diagnosis in Dermatopathology

Discussions

The interstitial expression of granuloma annulare and of papular mucinosis have several findings histopathologic in common, among them mesenchymal cells with abundant pink cytoplasm scattered among bundles of collagen, multinucleate cells in section…