Multiple pilosebaceous cysts

We report two patients initially diagnosed as having steatocystoma multiplex (SM), Other cysts showed characteristics of eruptive vellus hair cyst (EVHC). More than 30 and 14 cysts, respectively, were removed with histological hybrid characteristics of SM and EVHC. This suggests that SM and EVCH are two closely related entities, which represent a naevoid malformation in the area where the sebaceous duct and hair follicle meet.     

Clinical and histologic features of 64 cases of steatocystoma multiplex

Steatocystoma multiplex (SM) shares many clinical features and may show overlapping histopathological features with eruptive vellus hair cyst (EVHC). Clinical data and pathologic features of 64 patients with SM were evaluated in detail. Most of the cases were sporadic, with an average onset age of 26 years and distribution on the arms, chest, axillae, and neck. All cases exhibited eosinophilic cuticle and lack of granular layer, and 17-42% displayed vellus hair, hair follicles, keratin, and smooth muscle components within the cavity, in the wall, or adjacent to it. The results of this study add further evidence to the hypothesis that SM is a hamartomatous condition and that SM and EVHC are variants of one disorder which originates in the pilosebaceous duct.     

Unilateral eruptive vellus hair cysts occurring on the face

Eruptive vellus hair cysts (EVHC) are small, cystic papules that usually occur on the chest and extremities. Their aetiology is unknown. Fewer than 10 cases of a variant form of EVHC that occur exclusively on the face have been reported. We describe a case of EVHC limited to the right side of the face. To the best of our knowledge, no case of unilateral EVHC has been reported.     

Treatment of multiple eruptive vellus hair cysts with carbon dioxide laser vaporization and manual lateral pressure

Treatment of eruptive vellus hair cysts (EVHC) is often unsatisfactory. Laser treatment has been described as an adequate treatment in a few reports. Pulsed carbon dioxide (CO₂) laser has been used effectively for facial EVHC and erbium:yttrium–aluminium–garnet laser has been used to treat truncal EVHC with variable outcomes. We report our experience with CO₂ laser and lateral manual pressure to extract the cysts as an effective treatment in two cases of EVHC. Good cosmetic results were obtained in both cases. No lesion recurrence was observed after a follow‐up of 10 years in the first case and 3 years in the second one. CO₂ laser vaporization and further extraction of cysts by manual lateral pressure might be an effective method to treat EVHC, achieving good cosmetic results and no recurrence.     

Clinicopathological features and expression of four keratins (K10, K14, K17 and K19) in six cases of eruptive vellus hair cysts

Six cases of eruptive vellus hair cysts (EVHC) were evaluated for histopathology and the immunohistochemical profile of Ki‐67 and four keratins (K10, K14, K17 and K19). The pathological hallmark of EVHC was the existence of vellus hair shafts within the cystic cavity, but atypical pathological changes included two or three cysts and a foreign‐body granuloma in three cases. Our results demonstrate that atypical pathological changes are not uncommon in EVHC, and indicate that based on keratin expression, it is likely that EVHC is derived from the infrainfundibulum and sebaceous duct.     

An alternative diagnostic method of eruptive vellus hair cysts: Report of a familial case with pruritus

Eruptive vellus hair cysts (EVHC) represent a developmental abnormality of vellus hair follicles. Up till now more than 150 cases of EVHC have been published in the literature, but it appears to be more common than recognized. The diagnostic hallmark is the presence of vellus hair shafts within the cystic space. Firstly to evaluate the potential benefit of new diagnostic method of EVHC using a dermatoscope and secondly to report a familial case of EVHC where females were only affected. Five women from the same family with a clinical diagnosis of EVHC were included in the study. The diagnosis of EVHC was confirmed by skin biopsy with histologic examination in four patients. New diagnostic approach of the cyst contents examination with using a handheld dermatoscope was performed in all patients. Numerous vellus hair shafts were detected on the images of the cysts content taken with dermatoscope and applying the above‐mentioned method in all patients. We suggest that it seems possible to differentiate EVHC by using the dermatoscope, which appears to be simple, quick, and less time consuming.     

Spitzoid melanoma in children: clinicopathological study and application of immunohistochemistry as an adjunct diagnostic tool

Introduction:  The term spitzoid melanoma (SM) is reserved for a rare group of tumors with striking resemblance to Spitz nevus, often developing in children diagnosed in retrospect after the development of metastases.
Objectives:  To determine the biological significance of SM and to analyze the effectiveness of adjuvant diagnostic techniques.
Materials and methods:  A retrospective, observational study of 38 cases of SM in patients younger than 18 years. Histological type, Clark level and Breslow thickness, radial and vertical growth phase, mitotic count/mm², ulceration, regression, vascular and perineural invasion, satellitosis, cytology and associated nevi were reviewed. An immunohistochemical analysis with HMB45 and Ki67 was performed in 10 cases. These features were correlated to patient's stage and outcome.
Results:  Analysis of histological and immunohistochemical features should allow accurate diagnosis in most cases. Given the low mortality rate, no conclusions about the prognostic significance of histological parameters of the primary tumor could be established.
Conclusion:  We report the largest series of SM from a unique center. Although these patients may have a better prognosis than adults, some patients with SM develop metastasis and die, particularly after age 11 years. Therefore, we recommend using the same treatments as in adults.     

Eruptive vellus hair cysts: report of a new case with immunohistochemical study and literature review

Eruptive vellus hair cysts (EVHC) are rather uncommon lesions, of which 222 cases have been published in the literature. Their etiopathogenesis is poorly known. We report herein a new typical case of EVHC that was studied immunohistochemically. A 15-year-old male presented with a 4-year history of progressively developing small brown-gray papules on the trunk and extremities. Microscopically the lesions consisted of small epidermoid cysts containing vellus hairs. Immunohistochemically, the lesions expressed keratin 1/10, calretinin and p63 but no epithelial membrane antigen, filaggrin or androgen receptors. A review of the relevant literature shows that EVHC may be inherited or acquired and may be associated to other genodermatoses, namely sebocystomatosis. They could be due to hamartomatous follicular growth, to a trouble in infundibular keratinization leading to vellus hair follicle occlusion, or represent an example of acquired hamartoma. Although benign, this condition is difficult to treat.     

Eruptive vellus hair cyst and epidermoid cyst in a patient with pachyonychia congenita

We report the first case of pachyonychia congenita (PC) associated with both eruptive vellus hair cyst (EVHC) and epidermoid cyst. The patient is a 12-year-old Japanese girl who presented with two natal teeth at birth. She had thickening and discoloration of the fingernails and toenails, plantar hyperkeratosis, palmar-plantar hyperhidrosis and multiple cutaneous cysts. Histologic examination revealed EVHC and epidermoid cyst.     

Eruptive Vellus Hair Cysts

We report the results of the first systematic review of the worldwide literature on eruptive vellus hair cysts (EVHC). It is likely that EVHC are less rare than it may appear from the scarcity of related publications in the literature. EVHC may be present at birth and may appear at any age, although they show a clear trend towards occurring during the first 3 decades of life. A strong clue to the heavy influence of genes on the occurrence of EVHC is provided by the numerous reports of families in whom two or more members were affected. EVHC lesions present clinically in a rather monomorphous fashion, i.e. round, dome-shaped, skin-colored, asymptomatic, soft-tender papules with a smooth surface and grouped or disseminated in a symmetric pattern. EVHC may affect any cutaneous area, even if the upper part of the body and some distribution patterns are particularly frequent and recognizable, i.e. cephalic, upper trunk around the midline, upper limb including axillae, and proximal lower limb. Such a distribution is likely not random and seems to grossly overlap with that of pilosebaceous and apocrine units. Like clinical morphology, the histologic features of EVHC papules are rather monomorphous, indeed, the diagnostic hallmark being the presence of vellus hair shafts within the cystic space. Peculiar subgroups (familial, late-onset, unilesional, and associated with steatocystoma multiplex) are also identified and discussed. In conclusion, EVHC are basically a cosmetic concern to patients but represent a chronic and difficult-to-treat condition. On the basis of our review, future studies are warranted, mainly concerning (i) further nosographic framing involving genetic and tissue analysis, (ii) implementation of non-invasive diagnostic procedures, and (iii) therapeutic trials of interventions shown to achieve some effectiveness.     

Eruptive Vellus Hair Cyst

Eruptive vellus hair cysts (EVHC), first described by Esterly et al. in 1977, present as asymptomatic aggregations of one to four discrete papules, each measuring up to 2 mm.¹ These lesions are pigmented and range in color from red-brown to grey-black. They are found most commonly on the chest, though they also have been reported on the forearms, thighs, popliteal fossae, forehead, and eyelids.
The etiology of EVHC is unknown but may represent an abnormality of the development of vellus hair follicles. This condition does not appear to show a predilection toward either sex, and an autosomal dominant pattern of inheritance has been postulated.² Arising spontaneously, the lesions are usually found in the young-to-middle-aged patient. Though EVHC have not been responsive to oral vitamin A therapy or keratolytic agents; the cyst may resolve spontaneously in some patients. One author³ suggests this may occur via transepithelial elimination, while another author⁴ postulates that their resolution is due to an intracutaneous foreign body reaction.
Histologic examination reveals that the cysts are found in the middermis. They are lined by several layers of squamous epithelium and contain laminated keratinous material. Vellus hair shafts may be seen within the confines of the cyst at various planes of the section. There often is a rudimentary follicle associated with the wall of the cyst. Vellus hairs, best seen under polarized light, are characteristic of this condition. Unless the integrity of the cyst wall has been violated, there is no evidence of inflammation.     

Atypical neurothekeoma: a new case and review of the literature

Background:  Neurothekeoma is a rare neoplasm ascribed into the broad category of benign peripheral nerve sheath tumors. The atypical cellular variant of this neoplasm, showing a peculiar histological pattern, has been very rarely reported in literature.
Methods:  The clinical, histopathological and immunohistochemical profile of a new case of atypical cellular neurothekeoma in a 32-year-old woman is reported.
Results:  The described neoplasm showed the histological features of atypical variant of cellular neurothekeoma with high-rate mitotic activity and deep penetration into subcutaneous fat.
Conclusions:  Because only few cases of atypical neurothekeoma have been reported in literature, clinical and morphological available data on this neoplasm are very few, and its prognosis remains uncertain; anyway, dermatologists should be aware of histological features of this neoplasm for which a complete surgical excision is recommended.     

Eruptive vellus hair cysts and steatocystoma multiplex. Variants of one entity?

Summary Eruptive vellus hair cysts and steatocystoma multiplex are two clinically similar conditions which show multiple papules and nodules, mainly located over the anterior chest wall. Most cases can be differentiated on histological examination, but in some patients overlapping histological features have been described. We present a patient who showed features of both entities and interpret this as suggesting that eruptive vellus hair cysts and steatocystoma multiplex are variants of one disorder which originates in the pilosebaceous duct.     

Panniculitis: clinical overlap and the significance of biopsy findings

Background: Panniculitides are well-recognized clinicopathologic entities but the non-specificity of their clinical and pathological features often troubles the diagnostician.
Methods: This study retrospectively evaluates the clinical overlaps and the significance of histological findings among various panniculitides.
Results: The clinical evaluation in 55 panniculitides cases suggested the diagnosis of typical erythema nodosum (EN) in 26 cases, atypical EN in 17 cases, atypical nodular vasculitis (NV) in two cases, soft tissue infection in five cases and five cases remained unclassified. Skin biopsy evaluation provided definite panniculitis diagnosis in 53 cases including EN (28 cases), leukocytoclastic vasculitis (seven cases), NV (four cases), superficial thrombophlebitis (ST) (two cases), eosinophillic panniculitis (EP) (three cases), infection-related panniculitis (five cases), and one case each of erythema nodosum leprosum (ENL), lupus panniculitis (LP), pancreatic fat necrosis and acne conglobata with two cases remaining unclassified. Histologically, 'predominantly septal' and 'mixed panniculitis' were the chief inflammatory patterns in EN cases, while mixed panniculitis was seen in most LCV cases and predominantly lobular and mixed panniculitis in NV cases.
Conclusions: Biopsy evaluation of a panniculitis lesion is usually significant, and the application of a combination of histologic features rather than of a single biopsy finding or an inflammatory pattern is helpful in the diagnosis of panniculitis.     

Linear melanonychia due to subungual keratosis of the nail bed: a report of two cases

Longitudinal melanonychia displaying features of keratinized acanthoma is described in two patients. In both cases, a pigmented band consisting of a subungual keratinized epithelial ridge originated in the nail bed. We have been able to show, using the clinical and histological findings, that the origin of the pigment is linked to its synthesis within the acanthoma of the nail bed. These lesions are reminiscent of pigmented seborrhoeic keratosis. The horny cysts are replaced, because of the special physiological longitudinal arrangement of the ridges in the nail bed, by a single, prominent, longitudinal, keratinized and pigmented mass.     

Two Pilosebaceous Cysts with Apocrine Hidrocystoma in One Biopsy Site: A Spectrum of the Same Disease Process?

A 28-year-old woman presented with multiple, asymptomatic, erythematous to bluish papules located on the chest. Histopathologically, three round, well defined cystic structures were seen on the upper and lower dermis. The first cyst was milia, the second was apocrine hidrocystoma and the other, largest cyst was an eruptive vellus hair cyst (EVHC). A diagnosis of multiple pilosebaceous cysts combined with apocrine hidrocystoma was made. Since the milia and EVHC originate from the pilosebaceous unit, and the apocrine duct opens to the pilosebaceous orifice, we suggest that they can occur simultaneously in the same unit.     

Bullous lesions in acrodermatitis enteropathica delaying diagnosis of zinc deficiency: a report of two cases and review of the literature

Acrodermatitis enteropathica (AE) is a rare disorder associated with poor absorption of zinc. A variety of clinical and histological findings have been reported in the literature, described mainly in isolated case reports. Because of the varied nature of these cases, the histological features of AE are described often as non-specific. We describe lesions of AE in two patients who presented with vesiculobullous and erosive skin lesions, both showing intra-epidermal, inflammatory vesiculation with surrounding eosinophilic epidermis and necrotic keratinocytes. The lack of clinical suspicion of AE led to their misdiagnosis. We present these two patients to further characterize the bullous variant of AE, and we review the previously reported clinical and histopathological findings.     

Pruritic bluish-black subcutaneous papules on the chest

Steatocystoma multiplex (SM) is characterized by multiple dermal cysts involving the pilosebaceous glands. Although most presenting cases are sporadic, there is a rare familial syndrome involving a mutation in keratin 17 (K17) that is inherited in an autosomal dominant fashion. SM often presents concomitantly with eruptive vellus hair cysts (EHVS) and pachyonychia congenital type 2 (PC-2). We report a sporadic case of SM in a 21-year-old man.     

Histological characterization of Darier's disease in Tunisian families

Background  Darier's disease (OMIM 124200) is an autosomal-dominant skin disorder characterized by warty papules and plaques in seborreheic areas, palmo-plantar pits and distinctive nail abnormalities. The disease has complete penetrance in adults and variable expressivity. It is caused by mutations in the ATP2A2 gene, which encodes the sarco/endoplasmic reticulum Ca²⁺ ATPase type 2 isoform (SERCA2).
Objective  We report histological investigations of six unrelated Tunisian families including 15 affected individuals with Darier's disease mutations.
Results  The typical histological features of Darier's disease have been observed in the 15 patients. Variable histological features have been observed among Tunisian patients ranging from mild to moderate lesions of Darier's disease. A significant correlation has been observed between the clinical presentation of the Darier's disease (mild or moderate) and the intensity of the histological features. Isolated acral form of Darier's disease was seen in one case. Two distinct original associations have been observed: Darier's disease/pemphigus vulgaris in one patient and Darier's disease/ichtyosis in the other patient.
Conclusion  Our findings confirmed the clinical heterogeneity of Darier's disease on the basis of histological study. The intensity of the histological features could be closely correlated to the severity of Darier's disease clinical presentation.     

Clinicopathologic features of epidermal cysts of the sole: comparison with traditional epidermal cysts and trichilemmal cysts

BACKGROUND: It has been described that the etiology of epidermal cysts on acral skin is different from that on non-acral skin; however, no papers have been published regarding the detailed histological differences between acral and non-acral epidermal cysts. In this study, we compared the clinicopathologic findings of epidermal cysts of the sole with those of traditional epidermal cysts and trichilemmal cysts. METHODS: The cases studied were 12 epidermal cysts of the sole, 35 traditional (non-acral) epidermal cysts, and 12 trichilemmal cysts. The age and sex of the patients and the site, size, and microscopic findings of the lesions were evaluated.The pattern of keratinization was specifically focused on the evaluation of microscopic findings. RESULTS: Microscopically, most of the epidermal cysts of the sole showed the presence of parakeratosis and focal lack of a granular layer at least at the upper portion of the cyst wall. The cyst content of the epidermal cysts of the sole was predominantly compact orthokeratotic material. These pathological findings could be explained by the pathogenesis of epidermal cysts of the sole, namely invagination of the surface epidermis. CONCLUSION: Our study indicates that most cases of the epidermal cyst of the sole are considered to be a true traumatic epidermal inclusion cyst.