Sweet Syndrome precipitated by Mycobacterium abscessus in a Laotian Man with Autoantibodies to Interferon Gamma.

Autoantibodies to interferon γ, part of the first line of defense in the human immune response, constitutes a rare form of an acquired immunodeficiency in HIV-uninfected adults that can predispose to disseminated atypical mycobacterial infection. Particularly, this has been described in people of Southeast Asian origin. In this case report, we describe a previously healthy, Laotian man who presented with skin lesions consistent with Sweet syndrome that were later found to be precipitated by disseminated atypical mycobacterial disease. Extensive immunological workup revealed the patient to have autoantibodies to interferon γ, rendering him susceptible to this infection. Our report demonstrates a complex case with a multilayered diagnosis, while inviting perspective from multiple specialties. This enigmatic case emphasizes the importance of a broad differential with special attention to demographics while demonstrating the difficulty in treating certain atypical infections that are inherently multidrug resistant.

Lichenoid dermatoses involving the vulva: A clinical-pathologic correlation✰.

The lichenoid tissue reaction pattern generally signifies cytotoxic damage to the epithelium. When such reaction pattern occurs on vulvar skin or mucosa, the effects can result in considerable morbidity. None of the entities discussed in this review are entirely unique to the vulva, however, some entities may classically occur at this site, while others tend to be widespread diseases that may incidentally affect vulvar skin and mucosa. Given the complex anatomy of the vulva and the bridging of a site showing both keratinizing squamous epithelium and non-keratinizing squamous mucosa, histopathologic features may display variation in presentation. Although identification of a "lichenoid reaction pattern" alone may provide insight into the disease process, understanding of clinical presentation and specific sites of involvement, along with recognition of the nuanced features of the disease entities can help establish a specific diagnosis. Accurate histopathologic diagnoses by pathologists can improve the ability for treating clinicians to implement timely and effective treatment.

Consecutive Immunohistochemical Staining on a Single Slide is Effective in Confirming Melanocytic Derivation.

BACKGROUND: Metastatic melanoma in sentinel lymph nodes is often elusive to detect with morphology alone. Per American Joint Committee on Cancer staging guidelines, a single atypical melanocyte in lymph node qualifies as metastasis, whether identified by morphology or immunohistochemistry, but single cell staining must be convincing. We propose that the use of a second immunohistochemical run performed on a single slide will allow for more confident diagnosis of micrometastases. MATERIALS AND METHODS: We designed a technical study to determine whether a second antibody application on previously stained slides can successfully detect the same population of cells. Melanocytic neoplasms were stained with SOX-10 using Ventana Benchmark Ultra stainers, coverslipped, and examined, followed by coverslip removal and application of MART-1 (Ventana A103). The order of antibody application and chromagen detection kit (AP-RED vs. DAB) was reversed to establish reliability and robustness of the protocol. RESULTS: All melanocytes marked with SOX-10 and MART-1, and produced a range of staining quality that varied based on order of stain application and chromagen kit were used. The optimal combination was red MART-1 applied first followed by brown SOX-10 applied second. CONCLUSIONS: Consecutive staining of melanocytes with SOX-10 and MART-1 may improve diagnostic confidence of melanocyte identification, particularly in detection of single cell, micrometastases in sentinel lymph nodes or in situations where dual immunohistochemical stains may be unavailable.