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.

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.

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.