Differential Diagnosis in Dermatopathology

Metastatic carcinoma from a breast vs. Morpheiform basal-cell carcinoma

Cutaneous and subcutaneous lesions, usually nodules, that have become keratotic, crusted, and ulcerated as a consequence of infection by a variety of deep fungi, i.e., fungi situated in the dermis and subcutis, some of which may be disseminated to o…

Histologic Diagnosis of Inflammatory Skin Diseases

Errors and Reasons

Error: Abortive is an accurate modifier of particular pathologic processes, e.g., abortive dermatofibroma, abortive morphea, and abortive T-cell lymphoma. Reason: The idea itself is abortive! For example, what is called “abortive T-cell lympho…

Histologic Diagnosis of Inflammatory Skin Diseases

Subcutaneous Fat

The subcutaneous fat, like the dermis, is derived embryologically from mesenchyme. Primitive mesenchymal cells give rise to fibrocytes and to adipocytes. An adipocyte synthesizes so much fat in its cytoplasm that the lipid displaces and flattens the…

Differential Diagnosis in Dermatopathology

Differential Diagnosis

…art of the dermis 5. Neoplastic cells found sometimes within lymphatics 5. Neoplastic cells are present within lymphatics 6. Neoplastic cells not “basaloid,” i.e., their cytoplasm is abundant 6. Neoplastic cells “basaloid,”…

Differential Diagnosis in Dermatopathology

Discussions

In general, neoplasms metastatic to the skin present little difficulty in differential diagnosis from neoplasms primary in the skin. Carcinoma of the breast is an exception. If there are but a few neoplastic cells and numerous inflammatory cells sca…

Histologic Diagnosis of Inflammatory Skin Diseases

Blood Vessels

Blood vessels in the skin of an embryo come into being when mesenchymal cells arranged in an intricate network arborize and encircle conduits that are seen through a microscope as mere spaces. The dermal vasculature consists of a superficial and a d…

Histologic Diagnosis of Inflammatory Skin Diseases

Introduction

Capability for accurate diagnosis of inflammatory skin diseases, clinically and histopathologically, requires familiarity thoroughly with embryologic, histologic, and anatomic aspects of the skin. Although examples of this precept are legion, only a…

Histologic Diagnosis of Inflammatory Skin Diseases

Destombes-Rosai-Dorfman disease

Destombes-Rosai-Dorfman disease Synonyms Rosai-Dorfman disease Rosai-Dorfman histiocytosis Sinus histiocytosis with massive lymphadenopathy Presentation stereotypical Age and sex Usually in males under 25 years of age Distribution of lesions Localiz…

Histologic Diagnosis of Inflammatory Skin Diseases

Tuberculosis

Tuberculosis Synonyms Lupus vulgaris Presentation stereotypical Age and sex Any age in both sexes, usually adults Distribution of lesions Localized or widespread, depending on the manifestation specific of the disease Individual lesions Papules, pla…