A Single-Center Surgical Experience of Interhemispheric Epidermoids and Proposal of a New Radiological Classification.

BACKGROUND: Epidermoids account for <1.5% of all intracranial tumors. Overall, the cerebellopontine angle has been the most commonly reported location. In the supratentorial compartment, epidermoids will usually be found in the suprasellar area, sylvian fissure, and intraventricular area. The interhemispheric fissure represents an extremely rare location for supratentorial epidermoids, with limited cases reported previously. Surgery of an interhemispheric epidermoid can be challenging because of its adherence to the anterior cerebral artery branches or the brain parenchyma itself. In the present study, we have reported the largest Series of interhemispheric epidermoid tumors to better understand the clinical behavior, radiological features, and surgical outcomes. METHODS: In the present study, we retrospectively evaluated the data from 22 consecutive patients with interhemispheric epidermoids treated surgically during the past 10 years (2009-2019) at our center. During the same study period, we had treated 2355 patients with brain tumors (both primary and secondary), including 262 patients with intracranial epidermoids. Therefore, interhemispheric epidermoids comprised 0.009% of all brain tumors and 8.4% of all intracranial epidermoids in our experience. These patients all had newly diagnosed tumors and had undergone surgery for the first time at our center. All surgical specimens had been confirmed histopathologically. RESULTS: The mean age of the patients was 31 years (range, 17-61 years), with a male predilection. Seizures and headache were the most common mode of presentation. The average tumor size was 5.2 cm (range, 3.5-10 cm). Of the 22 tumors, 21 were in the anterior two thirds of the fissure. Anatomical distortion of the corpus callosum was seen in 13 patients (59%). The extent of excision was total in 17 (77.3%), near total in 3 (13.6%), and subtotal in 2 (9%) patients. The near or subtotal excisions had been necessary because of either tumor adherence to the pericallosal artery (n = 3) or a missed tumor lobule (n = 2). The mean follow-up time was 32 months, with no tumor recurrence. CONCLUSION: Interhemispheric epidermoids can often reach a large size with substantial lateral extension found at diagnosis. The position of the anterior cerebral Artery branches can help to differentiate interhemispheric epidermoids from radiologically similar corpus callosum, velum interpositum, and cavum septum pellucidum epidermoids. Complete surgical excision with minimal complications is feasible, with good long-term outcomes.

Epidermal Nevi and Related Syndromes - Part 2: Nevi Derived from Adnexal Structures. / Nevus epidérmicos y síndromes relacionados. Parte 2: Nevus derivados de estructuras anexiales.

Epidermal nevi are hamartomatous lesions derived from the epidermis and/or adnexal structures of the skin; they have traditionally been classified according to their morphology. New variants have been described in recent years and advances in genetics have contributed to better characterization of these lesions and an improved understanding of their relationship with certain extracutaneous manifestations. In the second part of this review article, we will look at nevi derived from the adnexal structures of the skin and associated syndromes.

The clinical, histological and immunohistochemical characteristics and nomenclature of meibomian gland ductal cysts (intratarsal keratinous cysts) and eyelid steatocystomas.

PurposeMeibomian gland ductal cysts (MGDCs) and steatocystomas are epithelial lined, keratin-containing lesions of the eyelids. MDGCs are variably called tarsal keratinous cysts, intratarsal keratinous cysts of the meibomian glands, intratarsal inclusion cysts, epidermal cysts and epidermoid cysts. Both lesions are poorly described in the literature. We report a series of seven MGDC and steatocystomas, and examine their clinical, pathological and immunohistochemistry features and their management and outcomes.Patients and methodsA retrospective review of case notes and histopathology slides of all MGDCs and steatocystomas identified at one major histopathology service in South Australia between 2013 and 2015.ResultsSeven cases were identified, with an average age of 64. The lesions range from 4 to 18 mm diameter and are firm, well-circumscribed and non-tender, and sometimes the keratin-filled cyst protrudes visibly under the tarsal conjunctiva. Two cases were previously misdiagnosed as chalazia but recurred after incision and curettage. Histologically, these lesions are lined by squamous epithelium but lack a well-formed stratum granulosum and can be distinguished by their immunohistochemical staining characteristics. Complete excision, including a wedge of underlying tarsal plate for MDGCs, is curative for with a follow up of 12-36 months.ConclusionsMGDCs and steatocystomas should be included in the differential of benign eyelid lesions. Diagnosing and differentiating these lesions from chalazia is important for determining the optimal management strategy.

Classification of cysts with follicular germinative differentiation.

BACKGROUND: Cysts are very common in the routine of dermatopathology but follicular germinative (trichoblastic) differentiation in cysts is seen rarely. The presence of follicular germinative differentiation in a cyst alerts to consider the possibility of a basal cell carcinoma (BCC) arising in a cyst. METHODS: Five cystic lesions with zones of follicular germinative differentiation were collected. Hematoxylin and eosin sections were reassessed for architecture, types of follicular differentiation and stromal characteristics; immunohistochemical studies with Ber-EP4 were analyzed. Articles about follicular germinative differentiation in cystic lesions were reviewed. RESULTS: Cystic lesions with follicular germinative differentiation have been described in the literature under various names including trichoblastic infundibular cyst, cystic trichoblastoma, cystic panfolliculoma (CPF), dermoid cyst with basaloid proliferations, folliculosebaceous cystic hamartoma and BCC occurring in infundibular cysts. The lesions presented by us could be classified as three cystic trichoblastomas, one CPF and one cystic hamartoma with follicular germinative differentiation. CONCLUSIONS: Histopathologically, cystic trichoblastomas can be separated from CPFs. Some lesions defy classification and may be regarded as cystic follicular hamartomas. The presence of follicular papillae and bulb-like structures, advanced follicular differentiation like that of inner and outer root sheath exclude the differential diagnosis of BCC arising in a cyst.

Dowling-Degos disease: case report and review of the literature.

Dowling-Degos disease (DDD) is an unusual pigmentary disorder usually caused by mutations in keratin 5. A 44-year-old woman in good general health presented due to the recent appearance of numerous pigmented macules on her axillary and anogenital skin. A biopsy showed lacy, finger-like epidermal extensions into the dermis which were heavily pigmented and associated with tiny cysts or dilated follicles. We view DDD as part of a spectrum of disorders which are morphologically related but vary in location and time of expression. In addition, both the clinical and histological differential diagnostic considerations are extensive.

Milia: a review and classification.

Milia are frequently encountered as a primary or secondary patient concern in pediatric and adult clinics, and in general or surgical dermatology practice. Nevertheless, there are few studies on the origin of milia and, to our knowledge, there is no previous comprehensive review of the subject. We review the various forms of milia, highlighting rare variants including genodermatosis-associated milia, and present an updated classification.

Quiste epidermoideo congénito de bazo / Congenital epidermoid cyst of the spleen

Se presenta el caso de una niña de siete años con una formación de aspecto quístico en el bazo hallado en examen ecográfico de rutina, con confirmación tomográfica y diagnóstico por anatomía patológica de quiste epidermoideo congénito.

Quiste epidermoideo congénito de bazo / Congenital epidermoid cyst of the spleen

Se presenta el caso de una niña de siete años con una formación de aspecto quístico en el bazo hallado en examen ecográfico de rutina, con confirmación tomográfica y diagnóstico por anatomía patológica de quiste epidermoideo congénito.(AU)

Cutaneous cysts of the head and neck.

PURPOSE: This article reviews the types of cutaneous cysts in patients referred to the Facial Lesion Clinic at John Peter Smith Hospital in Fort Worth, TX, and proposes effective treatment modalities based on lesion and patient variables. Cyst variables included proper identification, size of the lesion, and acute or chronic processes. Patient considerations included age, skin type, and location. Medical and social histories were not noted. PATIENTS AND METHODS: Eighty-two patients who had 1 or more cysts removed over the 5-year period from July 15, 1998 to July 14, 2003 were reviewed for age, gender, histologic diagnosis, anatomic location of the lesion, and complications. RESULTS: Patients with epidermal inclusion cysts (79%), followed by pilar cysts (9%), hidrocystomas and dermoid cysts (3% each), and multiple other diagnoses (less than 2%) were treated. Neither complications nor recurrent infections were reported during the 5-year interval. There were no recurrent cyst formations noted by return appointment. CONCLUSION: Cystic lesions of the head and neck may be treated effectively as long as they are correctly identified and treated in a specific manner.

[Intrascrotal epidermoid inclusion cyst. Report of a new case]. / Quiste epidermoide de inclusión intraescrotal. Aportación de un nuevo caso.

OBJECTIVES: We report a new case of intra-scrotal inclusion epidermoid cyst. METHODS: We describe the case of a 47-year-old male patient who referred an increase in size of the right hemiscrotum lasting seven months. Physical examination evidenced an intra scrotal mass of elastic consistency, which was confirmed by ultrasound. Testicular tumour markers were negative. Trans-scrotal excision of the lesion was performed. RESULTS: Pathology was compatible with inclusion epidermoid cyst. The patient remains asymptomatic on follow-up visits, without evidence of lesion relapse. CONCLUSIONS: We highlight the importance of establishing a nomenclature consensus for scrotal cystic lesions. We agree with other authors on the indication of simple excision of the lesion as a treatment with intention-to-cure. However, the limited number of cases makes the long-term follow-up of these patients recommendable.

Cisto epidermóide gigante de assoalho de boca / Giant epidermoid cyst in the floor of the mouth

Os cistos epidermóides säo cistos dermóides que contêm somente queratina em seu interior, näo possuindo anexos dérmicos. King (1994), em revisäo da literatura, encontrou, entre 198 casos de cisto dermóide de assoalho de boca, 108 cistos dermóides propriamente ditos, 32 cistos epidermóides e 7 teratomas. Os autores descrevem o caso de um paciente com 15 anos de idade, do sexo masculino, com uma massa cística de grandes dimensöes abaulando o assoalho de boca e a regiäo submental, submetido a exerése por via oral, cujo diagnóstico anátomo-patológico foi de cisto epidermóide. Neste relato de caso, discutimos a origem, localizaçäo, classificaçäo e abordagem cirúrgica dos cistos dermóides de assoalho de boca

Multiple eruptive milia: report of a case, review of the literature, and a classification.

A 71-year-old man presented with an acute onset of multiple white papules on the face and chest. Histologic sections demonstrated multiple milia. The rare condition of multiple eruptive milia occurs when crops of milia develop suddenly on the face and upper trunk. Rare isolated cases have been reported; however there has not been a review of these cases or an attempt to classify them. The authors report an additional case, review the literature, and suggest a classification of multiple eruptive milia.

Expression of keratins (K10 and K17) in steatocystoma multiplex, eruptive vellus hair cysts, and epidermoid and trichilemmal cysts.

We compared the patterns of keratin 10 (K10) and keratin 17 (K17) expression in epidermoid cysts, trichilemmal cysts, eruptive vellus hair cysts, and steatocystoma multiplex. Epidermoid cysts expressed K10 and eruptive vellus hair cysts expressed K17, whereas trichilemmal cysts and steatocystoma multiplex showed expression of both K10 and K17. Our findings support the opinion that eruptive vellus hair cysts, which stained negative for K10, and steatocystoma multiplex are distinct entities and not variants of one disorder.

Classification of cystic keratinizing squamous lesions of the rat lung: report of a workshop.

An international workshop of toxicologic pathologists reviewed cystic keratinizing squamous lesions of the rat lung. These lesions develop in response to the chronic inhalation of diverse particulate materials. Controversy exists over the biological significance of these changes and their relevance to humans. For the first time, in one place, a group of pathologists analyzed slides from all available studies. The workshop reached a consensus as to classification of these unique pulmonary tissue responses and offers diagnostic criteria for application. Although additional research is needed, this working classification scheme should serve as a practical interim approach for pathologists and regulatory agencies.

[Cranio-cerebral dermoid and epidermoid cysts. Classification and pathogenesis]. / Les kystes dermoïdes et épidermoïdes crânio-encéphaliques. Classification et pathogénie.

The pathogenesis of cranial dermoids and epidermoids is still controversial, owing to the multiple etiologies and locations of these lesions. We reviewed 25 cases, classified as follows: extradural lesion of the calvarium; of the occipital squama; dysraphic occipital lesions; and strictly intradural lesions. In the latter group, all lesions but one were in a paramedian, prenevraxial situation, and could be classified according to their situation relative to the tentorium cerebelli. In our series, strictly intradural dermoids are more often in a rostral situation, and epidermoids in a more caudal situation. Dermoids appear earlier in life than epidermoids, suggesting a more rapid growth due to eccrine secretion. For each group of lesions, the pathogenic hypotheses are studied. Inclusion of epidermal nests at different levels might result from traumatism, dysraphism, or developmental trouble in the lamination of the different layers of the meninges. Most intradural lesions trent to be related to the formation of Rathke's pouch and closure of the anterior neuropore.