Cary Chisholm

Neural and Neuroendocrine Neoplasms

Clinical: Benign reactive proliferation of nerves and fibroblasts in response to trauma. Often presents as a small, firm painful lesion typically associated with trauma found at any age or body site.

Functions and uses of immunohistochemical stains in cutaneous infiltrates of hematopoietic origin: A review for the practicing dermatologist

Background: Immunohistochemical stains, particularly those for cutaneous lymphomas, have similar-sounding names, which may lead to confusion among dermatologists who are not well versed in the terminology of the tools used for pathologic diagnosis. Also aiding in this is the fact that some familiar stains are constantly investigated for novel utility in different tumors, and a plethora of new stains regularly emerge in the peer-reviewed literature. Objective: To review the major stains encountered in dermatopathologic reports for cutaneous lymphomas. A select number of other stains are reviewed that are either new and under investigation in several cutaneous processes or have a new use described in recent reports. Methods: The peer-reviewed literature was searched and analyzed for the accepted purposes of using these markers. Results: All pertinent findings for these immunostains are reported with the purpose of educating the dermatology community. Conclusion: This review serves as a reference to clarify potentially confusing immunohistochemical stains.

Unusual and recently described cutaneous atrophic disorders

Cutaneous atrophic conditions are typically caused by changes in the dermis or subcutaneous tissue, sometimes consisting of the loss of a single fiber type. Since a significant decrease of subepidermal tissue is necessary for these lesions to be macroscopically atrophic, many conditions may not be appreciated as atrophy in the clinical setting. Clinicians should be familiar with the common or classic disorders causing cutaneous atrophy; however, there are a few new or rarely described atrophic conditions which are more difficult to identify and may not be atrophic clinically. This paper serves to describe the salient clinical and histological features of these new or rare disorders.

Lower Extremity Purpura in a Woman With Psychosis—Quiz Case

Cary Chisholm, MD; Brook Brouha, MD, PhD; Phillip Lee, MD; Doyle Hansen, MD; Clay Cockerell, MD; Scott & White Memorial Hospital, Temple, Texas (Dr Chisholm); Texas A&M University Health Sciences Center, College Station (Dr Chisholm); University of California, San Diego (Drs Brouha, Lee, and Hansen); University of Texas Southwestern Medical Center, Dallas (Drs Brouha and Cockerell); and Dermpath Diagnostics, Dallas (Drs Brouha and Cockerell)

Vascular Neoplasms and Malformations

This chapter will cover vascular anomalies according to the subcategories of vascular neoplasms (benign and malignant), vascular neoplasms of uncertain behavior, vascular malformations and vascular dilatations. Importantly vascular neoplasms are regarded as lesions, which undergo cellular proliferations, while vascular malformations are the result of aberrations in morphogenesis.

Vasculitic and Vasculopathic Disorders

This chapter is organized according to large, medium and small vessel vasculitis as proposed by the Chapel Hill Consensus Conference on the nomenclature of systemic vasculitis. The subset of small vessel vasculitic lesions will be addressed according to the predominant inflammatory cell infiltrate or feature (neutrophilic, urticarial, fibrosing, lymphocytic and granulomatous). The final section will address neutrophilic dermatoses and vasculopathies.

Drug Reaction Patterns

Reactions to drugs can vary quite a bit clinically as well as histopathologically. The different types of drug reactions will be grouped below according to their clinical name or histological pattern. Although they will be listed by histological reactions pattern(s), an attempt has been made to list them in decreasing order of incidence. The four most common drug reactions in the skin are morbilliform (exanthematous), urticarial, fixed drug, and the erythema multiforme/Stevens-Johnson syndrome/toxic epidermal necrolysis spectrum.

Cutaneous Lymphomas and Hematopathology

Lymphomas and non-neoplastic infiltrates of the skin are not uncommon lesions to encounter in routine dermatopathology specimens. When confronted with these entities in routine hematopathology practice (bone marrow biopsies and lymph nodes), diagnosis of hematopoietic neoplasms depends first on recognizing the overall architectural pattern. Analogous to their lymph node and bone marrow counterparts, diagnosis of cutaneous lymphomas and other malignant hematopoietic proliferations depends in part on the pattern of infiltration. Certain lymphomas have the propensity to form nodular aggregates while others invade in diffuse sheets of malignant cells. There are lymphomas that preferentially involve the epidermis and superficial dermis and those that arise primarily in the subcutaneous tissue. Given that skin contains numerous blood vessels and adnexal structures, infiltrates can either primarily or secondarily involve these compartments in varying degrees. After pattern determination, the diagnostician must also decide the size of the malignant cells since some tumors are comprised of small cells, others large cells, and still others mixed cell populations. The background milieu is also important: Are there lymphocytes, plasma cells, eosinophils, neutrophils, or perhaps histiocytes? All of these elements should be taken into consideration before the application of immunohistochemical stains, cytochemical stains, flow cytometry, or gene rearrangements.

Granulomatous (Non-infectious) Diseases

Clinical: Sarcoidosis is a common systemic disease which can affect nearly any organ system. Lungs, lymph nodes, and skin are the most frequently involved organs. Although typically indolent, spread into the central nervous system or heart can have high morbidity and mortality rates. It has a predilection for African-American and Hispanic patients. Asians are rarely affected. Sarcoidosis can present at any age, but adults are most often affected, particularly if there is skin involvement.

Epidermal Maturation Disorders

Clinical: Most common ichthyosis due to autosomal dominant profilaggrin mutation that presents in childhood with fine, white dry scaling skin resembling “fish scales” on pretibial and other extensor surfaces with sparing of antecubital and popliteal flexural areas. May be seen in conjunction with atopic dermatitis (also associated with profilaggrin mutations). Acquired ichthyosis presents in adults, most typically in the lower extremities, otherwise, clinically and histologically similar to icthyosis vulgaris.