Differential Diagnosis in Dermatopathology

Pyogenic granuloma, fully developed vs. Kaposi’s sarcoma, nodular

A systemic inflammatory process involving venules by deposits of fibrin within their wall in conjunction with neutrophils and nuclear “dust” of neutrophils in the dermis and, at times, the subcutaneous fat. The clinical manifestations ar…

Differential Diagnosis in Dermatopathology

Interstitial granuloma annulare vs. Interstitial mycosis fungoides

A systemic inflammatory process involving venules by deposits of fibrin within their wall in conjunction with neutrophils and nuclear “dust” of neutrophils in the dermis and, at times, the subcutaneous fat. The clinical manifestations ar…

Histologic Diagnosis of Inflammatory Skin Diseases

Silica granuloma

Silica granuloma Presentation stereotypical Age and sex No predilection Distribution of lesions On exposed sites usually Individual lesions Papules and nodules Course Protracted because the foreign body persists in the skin Findings histopathologic…

Histologic Diagnosis of Inflammatory Skin Diseases

Pyogenic granuloma

A systemic inflammatory process involving venules by deposits of fibrin within their wall in conjunction with neutrophils and nuclear “dust” of neutrophils in the dermis and, at times, the subcutaneous fat. The clinical manifestations ar…

Histologic Diagnosis of Inflammatory Skin Diseases

Granuloma annulare

A systemic inflammatory process involving venules by deposits of fibrin within their wall in conjunction with neutrophils and nuclear “dust” of neutrophils in the dermis and, at times, the subcutaneous fat. The clinical manifestations ar…

Histologic Diagnosis of Inflammatory Skin Diseases

Xanthogranuloma/Reticulohistiocytic granuloma

A systemic inflammatory process involving venules by deposits of fibrin within their wall in conjunction with neutrophils and nuclear “dust” of neutrophils in the dermis and, at times, the subcutaneous fat. The clinical manifestations ar…

A Clinical Atlas of 101 Common Skin Diseases

Folliculitis (Infundibulitis) and Pseudofolliculitis (Pseudoinfundibulitis)

Infundibulitis, usually a suppurative inflammatory process that involves infundibula, is either noninfectious, as in the case of pustules of acne vulgaris, or infectious, as in the case of pustules caused by Staphylococcus aureus. In contrast, pseud…

A Clinical Atlas of 101 Common Skin Diseases

Persistent Pigmented Purpuric Dermatitis

s, that involves the legs especially with purpuric macules and subtle papules (Schamberg’s disease), lichenoid papules (lichenoid purpura of Gougerot-Blum), and scaly papules (eczematid-like purpura of Doucas and Kapetanakis), all of which seem…

Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Skin: Nodular and Diffuse Dermatitis

…re 5.175 A&B. A nodule made up of epithelioid histiocytes: sarcoidosis. The nodular infiltrate throughout the dermis and in subcutaneous fat is composed mostly of epithelioid histiocytes, which qualifies this process as granulomatous, the actual…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

Images 10.43.1A: Nodular dermatitis, granulomatous + 10.43.1B: Interstitial and palisaded array of histiocytes around loci of deposits of mucin and degeneration of collagen = Granuloma annulare This is a presentation stereotypical of gran…