Evaluation of non-endemic pemphigus foliaceus in a large series of patients: a single-center retrospective study from Turkey focuses on the relapses

Abstract Background: Pemphigus foliaceus is exceedingly rare around the world, except within the few regions where it occurs as an endemic variant. Various factors can trigger immune mechanisms that induce pemphigus foliaceus or worsen its course. Objective: To determine the demographic and clinical characteristics of the patients with pemphigus foliaceus in a large series from a non-endemic country, investigate the triggering factors, and seasonal patterns. Methods: The data of the patients diagnosed with pemphigus foliaceus in the study's center between 1989-2018 were retrospectively analyzed. Results: Sixty-eight patients (mean age, 45.7 ± 14.5 years) were included in the study. The number of onsets reached its peak in spring-summer (p = 0.008). A total of 117 relapses occurred in 42 patients and were most common in spring-summer (not significant). Specific trigger factors were detected in 45 relapses. In the other 72 relapses, the peak was observed in spring-summer (p = 0.005). There were no significant differences in the demographic and clinical variables investigated between relapsed and non-relapsed patients. Study limitations: Retrospective design. Conclusions: Triggering factors could not be identified in more than half of the relapses in the study's series. The subgroup of relapses (without identified causes), as well as the onsets of the disease, showed a significant seasonal variation with a peak in spring-summer; however, the seasonal variable did not justify the total group of relapses. Although the seasonal variation may be caused by a combination of factors, UV radiation should be considered a trigger factor for the peaks in spring-summer, particularly in Turkey.

Dermatoscopy of the Borst-Jadassohn phenomenon in hidroacanthoma simplex

Abstract The Borst-Jadassohn phenomenon is a morphological finding that consists of the presence of well-defined nests of cells located in the spiny stratum of an acanthotic epidermis. One of the neoplasms where this phenomenon is found is hidroacanthoma simplex. This neoplasm is considered the intraepidermal form of the eccrine poroma. Despite its benign nature, malignant transformations are reported. The present article reports a case of hidroacanthoma simplex and discusses the dermoscopy of this phenomenon.

Melanoacanthoma: a potential pitfall of reflectance confocal microscopy

Abstract Melanoacanthoma is a rare variant of seborrheic keratosis, which is notable for dark pigmentation and fast radial growth, making it difficult to distinguish from melanoma. Histologically, it is characterized by proliferation of keratinocytes and dendritic melanocytes. The authors report a scalp lesion, fast growing, suspected by dermoscopy and confocal microscopy examination, with dendritic cells distributed throughout the lesion. Based on these findings, it was not possible to classify this lesion as clearly benign, so it was excised. Histopathologic evaluation and immunostain were consistent with melanoacanthoma.

Onychocytic matricoma

Abstract Onychocytic matricoma is a newly described tumor of the nail matrix. Clinically, it presents with localized thickening of the nail plate and melanonychia. Histologically, it represents a benign acanthoma of onychocytes. There are 8 cases reported in the literature. A 12-year-old girl presented with localized melanonychia and concurrent thickening of the nail plate restricted to the area of pigmentation affecting the right thumb, with no history of trauma or pain. We report a case of this rare tumor occurring in late childhood and provide a comprehensive review of its clinical presentation and differential diagnosis. Both clinicians and dermatopathologists should be aware of the presentation of onychocytic matricoma and include it in their scope of diagnosis of longitudinal nail bands.

Dermoscopic features of clear cell acanthoma

Abstract: Clear cell acanthoma is an uncommon type of benign epithelial tumor. Typically, it is a solitary lesion found on the lower limbs. It presents as a nodule or small plaque with slow and well-defined growth. Diagnosis used to be clinical and histopathological, but the advent of dermoscopy has led to an increase in diagnostic accuracy. We describe a case in which dermoscopy proved highly useful for diagnosis of the lesion.

Multifocal oral melanoacanthoma associated with Addison's disease and hyperthyroidism: a case report

SUMMARY Oral melanoacanthoma is a mucocutaneous, pigmented, rare, benign, and probably reactive lesion. This paper reports for the first time in the literature a case of multifocal oral melanoacanthoma in a patient diagnosed with Addison's disease and concomitant Graves' disease with hyperthyroidism. The patient presented with oral pigmented lesions, which were hypothesized to be mucosal pigmentation associated with Addison's disease. Due to their unusual clinical pattern, these oral lesions were biopsied and diagnosed as oral melanoacanthoma on histopathology and immunohistochemistry for HMB-45. At the moment of this report, the patient was being treated for her systemic conditions, but the lesions had not regressed. Reactive hyperpigmentation of the skin and mucous membranes may be found in Addison's disease and hyperthyroidism. This case reinforces the hypothesis of a reactive nature for oral melanoacanthoma and highlights the need for investigation of endocrine disorders in patients with multifocal oral melanoacanthoma.

"String of pearls pattern": report of three cases of non clear-cell acanthoma

Abstract The coiled and dotted vessels in a serpiginous arrangement or "string of pearls" is considered a classical vascular pattern associated with clear cell acanthoma. We present three cases of epidermal tumors different from clear cell acanthoma that have the same "string of pearls" vascular pattern. Even though most authors keep considering the "string of pearls" vascular pattern an almost pathognomonic sign of clear-cell acanthoma, the cases presented here suggest that some other epidermal tumors can also show this pattern.

Bilateral clear cell acanthoma of the areola and nipple: good response to topical corticosteroids

Abstract: Clear cell acanthoma is a rare, epidermal tumor not common in the area of the nipples; indeed, the literature describes only 8 cases, all showing unilateral presentation. We here report the first case of bilateral clear cell acanthoma with good response to topical corticosteroids. Case report: A sixteen-year old girl presented with 2 excrescent, fleshy, and exudative tumor masses in both nipples and areola mammae. A biopsy was conducted and confirmed clear cell acanthoma histopathologically. Treatment with strong corticosteroids resulted in rapid improvement and resolution. After one year of follow-up, the patient developed atopic dermatitis. Discussion: We describe the first case of bilateral clear cell acanthoma localized in the nipple/areola that resolved with powerful corticosteroids, suggesting a reactive etiology of the lesion.

Plasmoacanthoma

Abstract Plasmoacanthoma is an extremely rare verrucous tumor located on periorificial regions characterized by dense dermal plasmacytic infiltrates. Some authors classify it as a form of reactive plasma cell proliferation which represents a heterogeneous spectrum of mucocutaneous disorders. These plasma cell proliferations have been considered to be a benign immunologic inflammatory reaction to known or unknown stimuli. However, the etiology of plasmoacanthoma remains highly speculative. We report the case of a 40-year-old woman who presented with a lobulated warty lesion affecting the lower lip. Biopsy from the lesion was compatible with plasmoacanthoma, which remains an underreported disease in the dermatology literature.

Acantoma de células claras abdominal. Lesión infrecuente en localización atípica / Abdominal clear cell acantoma. Uncommon lesion in atypical location

Introducción. El acantoma de células claras es una lesión tumoral benigna relativamente infrecuente que muestra unas características histológicas que permiten su diagnóstico. Método. Presentamos el caso de un acantoma de células claras abdominal, localización infrecuente, en un paciente de 72 años. Resultado. El diagnóstico fue establecido tras el pertinente estudio histológico pues la clínica inespecífica y la localización atípica impedían la realización de un correcto juicio clínico. Conclusiones. Pretendemos con la presentación del presente caso poner de manifiesto la histología tan peculiar de esta lesión al tiempo que, a través de una amplia revisión bibliográfica, mostramos distintas localizaciones y presentaciones atípicas de dicha entidad.(AU)

Introduction. Clear cell acanthoma is a relatively rare benign tumoral lesion showing histological features that allow diagnosis. Method. We report the case of abdominal clear cell acanthoma, unusual location in a patient of 72 years. Results. The diagnosis was established after the relevant histological study as nonspecific clinical and atypical location prevented the realization of a proper clinical trial. Conclusions. We intend with the presentation of this case highlight the peculiar histology of this lesion while, through an extensive literature review, we show different locations and atypical presentations of this entity.(AU)

Benign follicular tumors

Abstract: Benign follicular tumors comprise a large and heterogeneous group of neoplasms that share a common histogenesis and display morphological features resembling one or several portions of the normal hair follicle, or recapitulate part of its embryological development. Most cases present it as clinically nondescript single lesions and essentially of dermatological relevance. Occasionally, however, these lesions be multiple and represent a cutaneous marker of complex syndromes associated with an increased risk of visceral neoplasms. In this article, the authors present the microscopic structure of the normal hair follicle as a basis to understand the type and level of differentiation of the various follicular tumors. The main clinicopathological features and differential diagnosis of benign follicular tumors are then discussed, including dilated pore of Winer, pilar sheath acanthoma, trichoadenoma, trichilemmoma, infundibuloma, proliferating trichilemmal cyst/tumor, trichoblastoma and its variants, pilomatricoma, trichodiscoma/fibrofolliculoma, neurofollicular hamartoma and trichofolliculoma. In addition, the main syndromes presenting with multiple follicular tumors are also discussed, namely Cowden, Birt-Hogg-Dubé, Rombo and Bazex-Dupré-Christol syndromes, as well as multiple tumors of follicular infundibulum (infundibulomatosis) and multiple trichoepitheliomas. Although the diagnosis of follicular tumors relies on histological examination, we highlight the importance of their knowledge for the clinician, especially when in presence of patients with multiple lesions that may be the cutaneous marker of a cancer-prone syndrome. The dermatologist is therefore in a privileged position to recognize these lesions, which is extremely important to provide further propedeutic, appropriate referral and genetic counseling for these patients.

Topical calcipotriol as a new therapeutic option for the treatment of clear cell acanthoma

Although uncommonly diagnosed, clear cell acanthoma represents an original source of speculative interest for dermatologists. Due to its clinical variability, it is often only recognized accidentally after histology. Dermoscopy has improved the reliability of clinical diagnosis of typical clear cell acanthoma thanks to the vascular pinpoint pattern and desquamative, peripheral collarette. Generally, therapy of clear cell acanthoma is oriented towards ablative solutions, such as surgery or cryotherapy. We propose a conservative therapy, based on the application of topical calcipotriol, which has produced complete regression after 2 months and no relapse one year after the end of treatment. A dermatoscope monitored all changes of clear cell acanthoma, showing its utility not only in diagnosis but also in therapeutic follow-up. This new therapeutic approach should support an inflammatory etiology of clear cell acanthoma, although further observations are needed to confirm this.

Clear cell acanthoma of the areola and nipple: clinical, histopathological, and immunohistochemical features of two Brazilian cases* / Acantoma de células claras da areola e do mamilo: aspectos clínicos, histopatológicos e imuno-histoquímicos de dois casos brasileiros

Clear cell acanthoma or Degos' acanthoma is a distinct disease concerning its clinical, histopathological, and immunohistochemical features. Its pathologic nature - whether neoplastic or reactive - is still under dispute among researchers. The disease shows a chronic course and often presents with a single papulonodular lesion on the lower limbs of adults. However, cases with multiple lesions, sometimes occurring in an eruptive fashion, and with clear variation in the size and shape of the cutaneous lesions have been reported. So far, five cases in which the lesions were exclusively located in the nipple area have been reported, all in Korean women. Four of these cases mimicked eczema and one, a polypoid nodule. The aim of this article is to present clinical, histopathological, and immunohistochemical features of two additional cases in Brazilian women with similar nipple topography.

O acantoma de células claras ou acantoma de Degos é uma doença bem individualizada quanto aos seus aspectos clínicos, histopatológicos e imuno-histoquímicos. Sua natureza patológica - se neoplásica ou reativa - ainda é debatida por pesquisadores. De evolução crônica, ocorre predominantemente nos membros inferiores de adultos, em geral como lesão papulonodular única. Entretanto, foram observados casos com lesões múltiplas, por vezes de caráter eruptivo, e com notável variação de tamanho e forma das eflorescências cutâneas. Há relatos de cinco casos com localização exclusiva na aréola e no mamilo, quatro simulando eczema e um como nódulo polipoide; todos ocorridos em mulheres coreanas. O objetivo deste trabalho é apresentar os aspectos clínicos, histopatológicos e imuno-histoquímicos de dois novos casos da doença, com idêntica topografia areolomamilar, observados em mulheres brasileiras.

Caracterización genómica de la integración in vitro del VIH-1 en células mononucleares de sangre periférica, macrófagos y células T de Jurkat / Genomic characterization of HIV-1 in vitro integration in peripheral blood mononuclear cells, macrophages and Jurkat T cells

Introducción: La mayor parte del genoma celular es accesible a la integración retroviral; sin embargo, se propone que este proceso no es aleatorio y es dependiente de cada retrovirus. Objetivos: Identificar y caracterizar las regiones del genoma humano en donde ocurre la integración del virus de la inmunodeficiencia humana de tipo 1 (VIH-1) en células mononucleares de sangre periférica, macrófagos y células T de Jurkat infectadas. Materiales y métodos: Se seleccionaron 300 secuencias de ADN humano obtenidas por el método de ligación mediada por PCR, previamente depositadas en el GenBank. Utilizando el programa BLAST, sólo 264 de ellas se incluyeron en el estudio, pues se pudo obtener información sobre localización cromosómica, genes anotados, secuencias repetidas, número de islas CpG y tiempo medio de replicación, entre otras variables genómicas. Estas secuencias se exportaron a otras bases de datos. Resultados: El 53% (140/264) de las integraciones se registraron en bandas G. El 70,45% de los provirus se localizaron en los genes humanos anotados, mientras que el restante lo hizo en elementos repetidos. En general, la selección del sitio de integración se relacionó con las características locales genómicas y estructurales de la cromatina, entre las que se incluyen secuencias Alu-Sx y L1, densidad génica y de islas CpG, remodelación de la cromatina y tiempo de replicación. Éstas influenciarían la interacción eficiente del complejo de preintegración con los genomas celulares. Conclusión: Se determinó que la integración del VIH-1 en los genomas celulares estudiados estaría condicionada por características diferenciales de la cromatina y por procesos epigenéticos que influirían la selección del sitio blanco de integración.

Introduction: Most of the infected host cell genome is available for retroviral integration; however, it has been proposed that this process does not occur at random and depends upon each type of retrovirus. Objective: The objective is to identify and characterize differences in human genome regions of peripheral blood mononuclear cells, macrophages and Jurkat T cells in which integration of HIV-1 occurs. Material and Methods: Three hundred human DNA genome sequences, previously deposited in the GenBank, were selected at random. Using program BLAST, only 264 of them were included in the study because relevant information about chromosomal position, associated genes, repetitive sequences, number of CpG islands and average replication time was available; these sequences were exported to other data bases for analysis. Results: 53% (140/264) of integrations were located on G bands. 70.45% of provirus was located in human genes and the rest was located in repetitive elements. In general the integration site selection was correlated with genomics and structural characteristics of cell chromatin including Alu-Sx and L1 sequences, gene and CpG island densities, remodeling of chromatin, and replication time. All of them would influence the efficient interaction between the pre-integration complex and target cell genomes. Conclusion: It was determined that HIV-1 integration in target cellular genomes would be conditioned by differential characteristics of associated chromatin and by epigenetic processes that would influence the selection of integration sites.

Acantoma de células claras: localización poco habitual / Acantoma of clear cells: little habitual location

El acantoma de células claras( ACC) es un tumor epidérmico benigno. La lesión típica es un pápula o placa bien delimitada, rojiza con algunas costras y escamas periféricas en su superficie. La localización habitual es en miembros inferiores, aunque se han detectado en otros lugares como abdomen y escroto. Presentamos un paciente varón de 80 años que consultó por lesión en areola mamaria izquierda de seis meses de evolución, asintomática; se le realizó biopsia cutánea llegando al diagnóstico de acantoma de células claras. Presentamos este caso clínico debido a la localización infrecuente y dificultad diagnóstica de esta lesión.