Morphologic mimickers of Cryptococcus occurring within inflammatory infiltrates in the setting of neutrophilic dermatitis: a series of three cases highlighting clinical dilemmas associated with a novel histopathologic pitfall.

A neutrophil-predominant inflammatory infiltrate in a cutaneous biopsy can be associated with a broad spectrum of diseases. Here we describe three cases showing a neutrophil-predominant dermal infiltrate admixed with abundant acellular bodies surrounded by capsule-like vacuolated spaces, which strikingly mimicked Cryptococcus. Two cases occurred within the settings of underlying hematologic malignancies; the third case was associated with immune dysregulation. Two patients were acutely ill in the medical intensive care unit. Fungal work-up, including cultures and multiple stains were negative. Because of clinical deterioration in these patients, transmission electron microscopy was pursued to definitively rule out fungal infection. In both cases, characteristics most compatible with autolysing human cells, not Cryptococcus, were identified. Chemotherapy and high-dose steroids were given, but both patients eventually succumbed to their diseases. To the best of our knowledge, these represent the first reported cases of autolysing human cells mimicking Cryptococcus organisms within neutrophilic infiltrates. They highlight the therapeutic dilemmas arising with histopathologic mimics, as well as the importance of thorough investigation to distinguish mimickers from true infectious organisms. We believe recognition of this microscopic pitfall will be useful to dermatopathologists faced with similar findings in the future, and may prevent unnecessary delay of appropriate therapy in acutely ill patients.

Cutaneous collagenous vasculopathy: a rare cutaneous microangiopathy.

Cutaneous collagenous vasculopathy is a rare microangiopathy of superficial dermal blood vessels. Patients present with telangiectatic macules, predominantly on the extremities. A skin biopsy specimen is necessary to distinguish cutaneous collagenous vasculopathy from generalized essential telangiectasia. Microscopically, cutaneous collagenous vasculopathy resembles the superficial telangiectasias of generalized essential telangiectasia but additionally shows hyaline material in thickened vessel walls. The amorphous pink material is periodic acid-Schiff-positive and resistant to diastase. We describe a series of four patients with cutaneous collagenous vasculopathy and highlight its clinical and histopathologic features.

Subcutaneous myxopapillary ependymal rest: a potential sign of spinal dysraphism.

Subcutaneous myxopapillary ependymal rests are heterotopias of neuroglial tissue that present in the subcutaneous tissue of the sacrococcygeal region. We report a case which presented as a flesh-colored, pedunculated papule near the gluteal cleft. The presence of a congenital lesion near the midline of the spine should alert the clinician to the possibility of spinal dysraphism and necessitates imaging before biopsy. Subcutaneous myxopapillary rests are benign but must be distinguished from their histologic mimic, subcutaneous myxopapillary ependymomas, which are low-grade tumors with metastatic potential.

Type I IFNs and their role in the development of autoimmune diseases.

BACKGROUND: Since their initial use in the 1980s, IFNs have become an essential component of the therapy for many diseases such as hepatitis and multiple sclerosis. Although they have been extremely useful in conditions that pose therapeutic challenges, complications associated with their use have been widely reported including emerging reports of several autoimmune diseases. Many of these reports have shed light on the pathogenesis of autoimmune disorders and helped to highlight not only the critical role of type I IFNs in defense against viral infections but also the pivotal role they occupy in the interface between innate and adaptive immunity. Many patients with autoimmune disease have increased responsiveness to type I IFNs (alpha/beta), and therapy with these cytokines has induced or unmasked autoimmune disease in many additional patients. OBJECTIVE: The objective of this paper is to discuss the role of type I IFNs in autoimmunity. METHODS: The literature regarding type I IFNs and autoimmunity was reviewed using the Medline database from 1950 to 2009. Search terms included 'interferon alpha' and 'autoimmune disease' and 'interferon beta' and 'autoimmune disease'. Case reports, case series, reviews and prospective studies were included in the analysis. RESULTS/CONCLUSIONS: In the literature a variety of autoimmune disorders have reportedly been induced by the use of type I IFNs, being used, although these are primarily in the form of case reports and case series. Nevertheless, there is a growing body of molecular evidence to support the clinical association. The role of IFNs in the induction of autoimmunity is complex with interplay of many genetic and environmental factors that influence the balance between normal and aberrant immune responsiveness, ultimately leading to the observed clinical manifestations.

JAAD Grand Rounds quiz. Asymptomatic necrotic ulcer on leg.

LEARNING OBJECTIVES: At the conclusion of this learning activity, physician participants should be able to assess their own diagnostic and patient management skills and use the results of this exercise to help determine personal learning needs that can be addressed through subsequent CME involvement. Instructions for claiming CME credit appear in the front advertising section. See last page of Contents for page number. Instructions: In answering each question, refer to the specific directions provided. Because it is often necessary to provide information occurring later in a series that give away answers to earlier questions, please answer the questions in each series in sequence.