Faculty Bibliography

BACKGROUND:SOX10 immunostaining has been considered a highly sensitive and specific marker for melanoma. But there is evidence suggesting that SOX10 positive cells can be present in dermal scars. Therefore, we investigated whether non-melanocytic cell types present in chronic inflammatory processes or benign lymph nodes express SOX10. METHODS:We retrospectively selected 20 benign lymph nodes and 20 cutaneous granulomatous dermatoses. SOX10, CD68, and Melan-A immunohistochemistry was performed in all cases. RESULTS:Scattered SOX10 positivity was found in 85% of lymph nodes, specifically in subcapsular and medullary sinuses and in 85% of granulomatous dermatoses. In granulomatous dermatoses, the Melan-A stain did not label the scattered SOX10 positive cells and it was difficult to determine if CD68 was co-expressed on the SOX10 positive cells. In the lymph nodes, the SOX10 positive cells did not co-express Melan-A or CD68. CONCLUSIONS:We report SOX10 positive cells detected in granulomatous dermatoses and benign lymph nodes. In lymph nodes, SOX10 positive cells were exclusively in subcapsular and medullary sinuses. Therefore, SOX10 is an excellent stain for evaluation of metastatic melanoma with the caveat that positivity in subcapsular and medullary sinuses can be of non-melanocytic origin; the use of additional melanocytic markers is recommended in this situations.

Nonmelanoma skin cancers, typically induced by ultraviolet light, are rarely found on the palmar aspects of the hands. Here, we describe a case of a basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) collision tumor on the palm of a 71-year-old woman. A brief review of literature regarding basal cell carcinoma of the palm and hand are provided, including etiology, diagnosis, and treatment recommendations.

Poison ivy, poison oak, and poison sumac are the most common causes of clinically diagnosed allergic contact dermatitis in North America. Approximately 50% to 75% of the US adult population is clinically sensitive to poison ivy, oak, and sumac. We reviewed the botany and history of these plants; urushiol chemistry and pathophysiology, clinical features, and the prevalence of allergic contact dermatitis caused by these plants; and current postexposure treatment and preventive methods, including ongoing investigations in the development of a vaccine (immunotherapy). Although extensive efforts have been made to develop therapies that prevent and treat contact dermatitis to these plants, there lacks an entirely effective method, besides complete avoidance. There is a need for a better therapy to definitively prevent allergic contact dermatitis to these plants.

Although allergists often evaluate rashes associated with allergic, IgE mediated etiologies, it is important to consider a wide range of differential diagnoses that includes inflammatory, infectious, and autoimmune etiologies. The case of a 58-year-old woman with a 1-year history of progressive pruritic rash that did not improve with topical creams and steroids is presented. The patient did not state any other symptoms, and a physical examination was notable for a widespread rash. After a detailed evaluation of the rash, a differential diagnosis was made, and results of a skin biopsy confirmed a specific diagnosis. Even in the context of a medical history of atopy, one must consider nonallergic causes of rash, including abnormal presentations of systemic conditions. It is important to determine the specific etiology of the rash because this will dictate treatment and prognosis and/or complications of the disease associated with the skin manifestations.

Linear vesicles or papules in a newborn can be a presenting sign of incontinentia pigmenti (IP). In this report, we present two cases of neonates with cutaneous manifestations of incontinentia pigmenti. In one case, mild peripheral eosinophilia was noted. No extra-cutaneous manifestations were noted otherwise in both cases after complete ophthalmological and neurological evaluations. These cases serve as a reminder for clinicians to consider IP in newborns presenting with linear vesicles or papules.