Eruptive purpuric papules on the arms; a case of chemotherapy-induced inflammation of actinic keratoses and review of the literature.

Chemotherapy-induced inflammation of actinic keratosis can present in patients with subclinical actinic keratoses that become erythematous and pruritic within weeks of initiating systemic chemotherapy. The reaction is limited to sun-exposed areas and, classically, histologic findings of parakeratosis and epidermal necrosis with keratinocyte nuclear pleomorphism are present. Exuberant reactions with extensive epidermal necrosis may lead to subepidermal vesiculation.

Congenital extrarenal malignant rhabdoid tumor in an infant with distal 22q11.2 deletion syndrome: the importance of SMARCB1.

Extrarenal rhabdoid tumor is a rare malignancy of infants and children, typically presenting in the soft tissue of deep, axial locations. We describe a rare dermal presentation of congenital extrarenal rhabdoid tumor in the left paraspinal region of a 6-month-old girl with germline deletion of chromosome 22q11.21q11.

Assessment of copy number status of chromosomes 6 and 11 by FISH provides independent prognostic information in primary melanoma.

Melanoma incidence has been rising steadily for decades, whereas mortality rates have remained flat. This type of discordant pattern between incidence and mortality has been linked to diagnostic drift in cancers of the thyroid, breast, and prostate. Ancillary tests, such as fluorescent in situ hybridization (FISH), are now being used to help differentiate melanomas from melanocytic nevi.

Features of plexiform fibrohistiocytic tumor in skin punch biopsies: a retrospective study of 6 cases.

Plexiform fibrohistiocytic tumor (PFHT) is a mesenchymal neoplasm of intermediate malignant potential, which typically presents as a dermal or subcutaneous nodule, and is therefore often sampled by skin punch biopsy where diagnostic features may be subtle or absent. We retrospectively analyzed a series of 6 cases of PFHT to highlight for dermatopathologists the features of PFHTs useful to distinguish it from the other entities in the differential diagnosis. On the basis of the proportion of spindled fibroblastic cells to histiocytoid nodules in the biopsy specimen, we divided PFHT into 3 histologic variants: cellular, fibrous, and mixed.

Immunophenotypic correlation between skin biopsy and peripheral blood findings in mycosis fungoides.

In mycosis fungoides (MF) with blood involvement, T-cell immunophenotypes in skin and blood have not been compared. Our aim was to evaluate T-cell immunophenotypes in skin by immunohistochemical analysis and compare results with flow cytometric (FC) findings in blood. Of 20 patients with MF with blood involvement, the immunophenotype was discrepant in 11 (55%).

Diagnostic pitfalls in syringocystadenocarcinoma papilliferum: case report and review of the literature.

We report the first case, to our knowledge, of syringocystadenocarcinoma papilliferum with p63-verified squamous differentiation and extensive dermal invasion accompanying in situ components. An 86-year-old woman presented with a neoplasm on the neck, and the intralesional heterogeneity typical of these neoplasms led to an initial diagnosis on needle biopsy favoring squamous cell carcinoma. Excision illustrated diverse morphology, raising a broad differential diagnosis, including more common extracutaneous malignancies, such as breast, gastrointestinal, and ovarian primary tumors.

Regulation of the psoriatic chemokine CCL20 by E3 ligases Trim32 and Piasy in keratinocytes.

Psoriasis is an inflammatory skin disorder with aberrant regulation of keratinocytes and immunocytes. Although it is well known that uncontrolled keratinocyte proliferation is largely driven by proinflammatory cytokines from the immunocytes, the functional role of keratinocytes in the regulation of immunocytes is poorly understood. Recently, we found that tripartite motif-containing protein 32 (Trim32), an E3-ubiquitin ligase, is elevated in the epidermal lesions of human psoriasis.

Widespread porokeratotic adnexal ostial nevus: clinical features and proposal of a new name unifying porokeratotic eccrine ostial and dermal duct nevus and porokeratotic eccrine and hair follicle nevus.

Porokeratotic eccrine ostial and dermal duct nevus and a similar condition, porokeratotic eccrine and hair follicle nevus, are rare disorders of keratinization with eccrine and hair follicle involvement. We describe the clinical features in 5 patients, all of whom had widespread skin involvement following the lines of Blaschko. Two patients presented with erosions in the newborn period as the initial manifestation of their disease; one had an associated structural anomaly, unilateral breast hypoplasia; and one adult had malignant transformation in the nevus with development of multifocal squamous cell carcinomas.

Verrucous porokeratosis of the gluteal cleft (porokeratosis ptychotropica): a rare disorder easily misdiagnosed.

Porokeratosis represents a heterogeneous group of disorders characterized clinically by a distinctive ridge-like border and histologically by cornoid lamellae. A verrucous variant of porokeratosis involving the gluteal cleft has been recently described. We present 5 new cases and review the current literature to highlight the clinical and histopathologic features of this disorder.

Disseminated dermal Trichophyton rubrum infection - an expression of dermatophyte dimorphism?

We present a case of disseminated dermal infection caused by Trichophyton rubrum (T. rubrum). This rare variant of dermatophytosis has an atypical clinical and histopathological presentation and occurs exclusively in immunosuppressed patients.

Sequelae of World War II: an outbreak of chronic cutaneous nontuberculous mycobacterial infection among Satowanese islanders.

Background: After World War II, residents of Satowan (population, 650 persons), an outer island in the state of Chuuk, Federated States of Micronesia, noted a high prevalence of a chronic, progressive skin disease known locally as "spam."

Methods: Island residents who had chronic, progressive verrucous or keloidal plaques for >3 months were considered case patients. Tissue specimens were obtained for culture, histopathological analysis, mycobacterial polymerase chain reaction (PCR), and comparison with the hsp65 gene of Mycobacterium marinum.

Mycobacterium marinum presenting as large verrucous plaques on the lower extremity of a South Pacific Islander.

Mycobacterium marinum is an environmental, nontuberculous mycobacteria found in fresh and salt water, causing disease in humans through traumatized skin. We describe a young, healthy South Pacific Islander with chronic, progressive large verrucous plaques on the left lower extremity, with cultures positive for M. marinum.

Orf-induced immunobullous disease: A distinct autoimmune blistering disorder.

Background: Many complications have been reported after orf infection, including lymphadenopathy, secondary bacterial infection, and erythema multiforme. Rare associations with papulovesicular eruptions, including a bullous pemphigoid-like eruption, have also been described.

Objectives: Our purpose was to clinically, histologically, and immunologically characterize two cases of orf-induced blistering disease, and to determine whether this condition represented a novel disease entity distinct from known immunobullous diseases.

Expression of vascular endothelial growth factor and its receptors in rosacea.

Background: Rosacea is a common chronic disease of unclear pathogenesis, characterised by inflammation and vascular abnormalities of the facial skin and ocular surface. Recognising that vascular endothelial growth factor (VEGF) is vasoactive and has inflammatory activities, the expression of this molecule and its receptors, VEGF-R1 and VEGF-R2, in rosacea was investigated.

Methods: Formalin-fixed, paraffin wax-embedded sections of skin obtained from 20 patients with rosacea were immunostained to detect expression of VEGF, VEGF-R1 and VEGF-R2, using an indirect methodology incorporating antigen retrieval.

Allele-specific polymerase chain reaction for the imatinib-resistant KIT D816V and D816F mutations in mastocytosis and acute myelogenous leukemia.

Oncogenic mutations of the receptor tyrosine kinase KIT contribute to the pathogenesis of gastrointestinal stromal tumors, systemic mastocytosis (SM), and some cases of acute myelogenous leukemia (AML). The D816V substitution in the activation loop of KIT results in relative resistance to the kinase inhibitor imatinib (Gleevec). Because this mutation occurs in 80 to 95% of adult SM, its detection has diagnostic and predictive significance.