Principales tipos de quistes en dermatopatología: Parte 2 / Main Types of Cysts in Dermatopathology: Part 2

Este es el segundo artículo de una serie de dos publicados en esta revista, en los que examinamos las características histopatológicas, así como el diagnóstico diferencial, de las principales entidades que se presentan en forma de estructuras quísticas y pseudoquísticas en la biopsia cutánea. En este segundo artículo, abordamos los quistes cutáneo ciliado, branquial, de Bartholino, onfalomesentérico, tímico, del conducto tirogloso, sinovial, y del rafe medio, así como el mucocele, el ganglión y los pseudoquistes auricular y mixoide digital. (AU)

This is the second article in a two-part series published in this journal, in which we examine the histopathological characteristics, as well as the differential diagnosis, of the main entities that present as cystic and pseudocystic structures in cutaneous biopsy. In this second article, we address ciliated cutaneous cysts, branchial cysts, Bartholin's cysts, omphalomesenteric cysts, thymic cysts, thyroglossal duct cysts, synovial cysts, and median raphe cysts, as well as mucocele, ganglion, and auricular and digital myxoid pseudocysts. (AU)

[Main Types of Cysts in Dermatopathology: Part 2]. / Principales tipos de quistes en dermatopatología: Parte 2.

This is the second article in a two-part series published in this journal, in which we examine the histopathological characteristics, as well as the differential diagnosis, of the main entities that present as cystic and pseudocystic structures in cutaneous biopsy. In this second article, we address ciliated cutaneous cysts, branchial cysts, Bartholin's cysts, omphalomesenteric cysts, thymic cysts, thyroglossal duct cysts, synovial cysts, and median raphe cysts, as well as mucocele, ganglion, and auricular and digital myxoid pseudocysts.

Principales tipos de quistes en dermatopatología: parte 1 / Main Types of Cysts in Dermatopathology: Part 1

Las estructuras quísticas son uno de los hallazgos más frecuentes en dermatopatología. Se trata de tumores quísticos y de pseudoquistes por acumulación de ciertas sustancias, por ejemplo, mucina. En una serie de dos artículos (de los cuales este es el primero) hemos revisado los principales tipos de quistes y pseudoquistes que pueden verse en la biopsia cutánea, examinando sus aspectos histopatológicos y los principales diagnósticos diferenciales. En esta primera parte, se abordan los quistes infundibulares, dermoides, vellosos eruptivos, foliculares pigmentados, pilonidales, tricolemales, de milium, híbridos y broncogénicos, así como el esteatocistoma, el hidrocistoma y los comedones. (AU)

Cystic structures represent one of the most common findings in dermatopathology. These encompass both cystic tumors and pseudocysts resulting from the accumulation of certain substances, such as mucin. In a two-part series (of which this is the first part), we have reviewed the principal types of cysts and pseudocysts that may be observed in cutaneous biopsies, examining their histopathological features and primary differential diagnoses. This first part encompasses infundibular cysts, eruptive dermoid cysts, pigmented follicular cysts, pilonidal cysts, tricholemmal cysts, milium cysts, hybrid cysts, bronchogenic cysts, as well as steatocystoma, hydrocystoma, and comedones. (AU)

Principales tipos de quistes en dermatopatología: parte 1 / Main Types of Cysts in Dermatopathology: Part 1

Las estructuras quísticas son uno de los hallazgos más frecuentes en dermatopatología. Se trata de tumores quísticos y de pseudoquistes por acumulación de ciertas sustancias, por ejemplo, mucina. En una serie de dos artículos (de los cuales este es el primero) hemos revisado los principales tipos de quistes y pseudoquistes que pueden verse en la biopsia cutánea, examinando sus aspectos histopatológicos y los principales diagnósticos diferenciales. En esta primera parte, se abordan los quistes infundibulares, dermoides, vellosos eruptivos, foliculares pigmentados, pilonidales, tricolemales, de milium, híbridos y broncogénicos, así como el esteatocistoma, el hidrocistoma y los comedones. (AU)

Cystic structures represent one of the most common findings in dermatopathology. These encompass both cystic tumors and pseudocysts resulting from the accumulation of certain substances, such as mucin. In a two-part series (of which this is the first part), we have reviewed the principal types of cysts and pseudocysts that may be observed in cutaneous biopsies, examining their histopathological features and primary differential diagnoses. This first part encompasses infundibular cysts, eruptive dermoid cysts, pigmented follicular cysts, pilonidal cysts, tricholemmal cysts, milium cysts, hybrid cysts, bronchogenic cysts, as well as steatocystoma, hydrocystoma, and comedones. (AU)

Idiopathic scrotal calcinosis: Is the cause still unknown? A case report.

INTRODUCTION AND IMPORTANCE: Idiopathic Scrotal Calcinosis (ISC) is a rare and benign dermatological condition, characterized by the formation of calcified nodules on the scrotal skin. CASE PRESENTATION: A 47-year-old man with a 15-year history of painless, chamois-colored nodules on his scrotum. Surgical excision of the affected skin was performed, followed by primary closure, with histopathological examination confirming ISC. The patient recovered well with no recurrence noted at a 14-month follow-up. CLINICAL DISCUSSION: The etiology of ISC remains uncertain, with theories ranging from dystrophic calcification of epidermal cysts to Dartos muscle degeneration. In this case, no signs of epithelial cells or anatomical structure degeneration were observed, supporting the idiopathic nature of ISC. Treatment is typically surgical and aimed at aesthetic or symptomatic relief. While surgery is generally effective, the literature indicates a variable risk of recurrence, underscoring the need for long-term follow-up. CONCLUSION: This report contributes to the understanding of ISC, highlighting its idiopathic nature and the diversity of its etiological theories. It reinforces the effectiveness of surgical treatment for symptomatic relief and underscores the importance of ongoing research to elucidate the condition's etiology and optimize patient care.

Gigantic occipital epidermal cyst in a 56-year-old female: A case report.

BACKGROUND: Gigantic epidermal cysts (GECs) are rare benign skin appendicular tumours also known as keratinocysts. GECs have a high incidence and their wall is made up of epidermis. Epidermal cysts can occur in any part of the skin; clinical manifestations include skin colour hemispherical swelling; cystic; mobile; 0.5 cm to several centimetres in diameter; and slow growth. CASE SUMMARY: Herein, we report a case involving a 56-year-old female with a GEC in the occipitalia. On July 25, 2023, a patient with a GEC was admitted to the neurosurgery Department of the Second Affiliated Hospital of Xi'an Medical University. The phyma was shown to be a solid mass during the operation and was confirmed to be a GEC based on pathological examination. CONCLUSION: Epidermal cysts are common cystic nodules on the surface of the body, the aetiology is unclear, the clinical manifestations can vary, and the misdiagnosis rate is high. However, giant epidermal cysts are rare. In most cases, however, the prognosis is satisfactory. This paper analyses and summarizes the population, location, clinical and pathological characteristics and pathogenesis of the disease to strengthen the understanding of this disease and improve the accuracy of clinical diagnosis.

[Main Types of Cysts in Dermatopathology: Part 1]. / Principales tipos de quistes en dermatopatología: parte 1.

Cystic structures represent one of the most common findings in dermatopathology. These encompass both cystic tumors and pseudocysts resulting from the accumulation of certain substances, such as mucin. In a two-part series (of which this is the first part), we have reviewed the principal types of cysts and pseudocysts that may be observed in cutaneous biopsies, examining their histopathological features and primary differential diagnoses. This first part encompasses infundibular cysts, eruptive dermoid cysts, pigmented follicular cysts, pilonidal cysts, tricholemmal cysts, milium cysts, hybrid cysts, bronchogenic cysts, as well as steatocystoma, hydrocystoma, and comedones.

[Optical coherence tomography for the diagnosis and differentiation of cutaneous cysts: a case series]. / Diagnose und Differenzierung von kutanen Zysten mit optischer Kohärenztomographie: eine Fallserie.

Cutaneous cystic lesions (n = 35) were examined with optical coherence tomography. Cysts were visible as a hyporeflective roundish area with a clear margin; in some cases, the epidermis was thinned. Epidermal cysts, trichilemmal cysts, and hidrocystomas had a linear margin representing the epithelium of the cyst, whereas mucoid pseudocysts showed no linear margin. Trichilemmal and epidermal cysts presented with hyperreflective content that corresponds to keratin. By visualizing the margin and the content of the cyst, it was possible to differentiate between different types of cysts.

Frequency and features of malignant tumors clinically mimicking cutaneous cysts: A retrospective chart review.

BACKGROUND: Many cutaneous lesions are clinically suspected as "cyst"; however, following histopathological examination, are found to be more significant lesions. Here, we examine the frequency and features of malignancies with cutaneous cysts in the clinical differential. METHODS: A retrospective study of surgical pathology specimens at the James A. Haley Veterans' Hospital from January 2018 to December 2022 was conducted. Cutaneous specimens containing the clinical diagnosis of "cyst" were included. The clinicopathological features were summarized. RESULTS: Premalignant or malignant neoplasms accounted for 4.5% of all specimens submitted with cysts in the clinical differential. Most cyst-mimicking cancers were basal cell carcinoma (BCC) or squamous cell carcinoma (SCC); however, cancers with poorer prognoses, such as Merkel cell carcinoma and melanoma, also clinically masqueraded as cysts. The BCCs were predominately nodular, and the SCCs were largely well-differentiated and invasive. Many exhibited clinical signs and symptoms compatible with benign cysts, such as central punctum, pain, and rapid growth. Identified risk factors included history of prior non-melanoma skin cancer diagnosis, previous excision, and immunosuppression. CONCLUSIONS: Many lesions clinically concerning cutaneous cysts were found to be malignancies following histopathological review. Accordingly, following biopsy all cyst-like lesions should be examined microscopically, especially in certain clinical contexts in which the incidence of skin cancer is increased.

Epidermal inclusion cyst embedded in benign fibrous histiocytic lesion with prominent epithelioid morphology.

Benign fibrous histiocytoma also known as dermatofibroma is one of the common mesenchymal neoplasms. It commonly develops in young adult with female predominance and predilection for the extremities, particularly lower extremities. Implantation of epidermis in the dermis or subcutaneous tissues may lead to the formation of epidermal inclusion cyst, which is the most common type of epithelial cyst. Development of epidermal inclusion cyst within a benign fibrous histiocytoma is a rare occurrence. This is a unique case of two unrelated lesions.

Clinicopathological Appraisal of Cutaneous Cysts: A 2-Year Retrospective Observational Study.

Background: Cysts, primarily epidermal and trichilemmal, are commonly seen in clinical practice. Rupture, infection, inflammation, and rarely malignant transformation may complicate the cysts. This study aims to analyze the clinicohistological features of cutaneous cysts. Materials and Methods: A retrospective review of patients with the diagnosis of cyst confirmed on histopathology over the past two years (2020-2021) was performed. Clinical details comprised of age, gender, site of involvement, size, duration, and associated symptoms. Histological examination included cyst wall lining, type of keratinization, complications like rupture, inflammation, foreign body giant cell reaction, calcification, and malignant change. Results: A total of 324 cases with mean age of 37.9 years and equal gender distribution were identified. Most frequent diagnosis was epidermal cyst in 89.8%, followed by trichilemmal cyst in 8.9% of cases. Rare types included follicular hybrid cyst, verrucous cyst, vellus hair cyst, and steatocystoma. Most common complication was cyst rupture in 54.3% of epidermal cysts. Proliferating epidermal and proliferating trichilemmal cysts were noted in one and two cases, respectively. Two cases revealed malignancy arising in the wall of epidermal cyst. Limitations: The retrospective study design and non-availability of follow-up data, especially for proliferating cysts and cysts with malignant transformation were the main limitations of this study. Conclusion: Histopathologic examination of excised cutaneous cysts is paramount in reaching accurate diagnosis of the type of cyst and associated secondary changes to enable appropriate management.

Epidermal cyst protruding from the occipital region of the scalp: a case report.

Introduction and importance: Epidermal cysts are the most common subcutaneous tumor typically observed on the scalp, face, neck, back, or trunk. Epidermal cysts conventionally range in size from 1 to 5 cm, with sizes greater than 5 cm rarely reported. Case presentation: Here, we present a case of a 58-year-old female housewife who presented to our surgery outpatient department (OPD) with a history of a mass in the left occipital region. The mass was first noticed 3 years back and was small and associated with mild itching. The mass progressively increased in size over the course of 3 years. Her present complaint was a painful mass associated with itching, headache, and pus discharge when compressed. The pain was relieved by taking medication. Clinical discussion: The epidermal cyst was confirmed on biopsy, and subsequent excision of the cyst was done under general anesthesia; the occipital bone was eroded by the inferior part of the cyst - reconstruction of scalp defect done by rotational scalp flap. Conclusion: Epidermal cysts, being a slow-growing benign tumor, can pose diagnostic difficulties, especially when located in the scalp area. In addition to that, when cranial bones and intracranial structures are affected by the cyst, they can even lead to complications and interventional difficulties.

Intramuscular epidermal cyst in the masticator space: a case report.

An epidermal cyst, also known as an epidermoid cyst or epidermal inclusion cyst, is the most prevalent type of cutaneous cyst. This noncancerous lesion can appear anywhere on the body, typically presenting as an asymptomatic dermal nodule with a visible central punctum. In the case presented herein, an epidermal cyst with uncommon features was misdiagnosed as a lymphatic malformation based on preoperative magnetic resonance imaging (MRI). A 61-year-old man came to us with a swollen left cheek that had been present for 11 months. The preoperative MRI revealed a 3 × 3.8 × 4.6 cm lobulated cystic lesion with thin rim enhancement in the left masticator space. The initial differential diagnosis pointed toward a lymphatic malformation. We proceeded with surgical excision of the lesion via an intraoral approach, and the specimen was sent to the pathology department. The pathological diagnosis revealed a ruptured epidermal cyst, indicating that the initial diagnosis of a lymphatic malformation based on preoperative MRI was incorrect. Epidermal cysts located under the muscle with no visible central punctum are uncommon, but should be considered if a patient presents with facial swelling.

Presentación simultánea de quiste epidermoide del ángulo pontocerebeloso y colesteatoma infiltrante del oído medio. Reporte de caso y revisión de literatura / Simultaneous presentation of an epidermoid cyst of the cerebellopontine angle and infiltrating cholesteatoma of the middle ear. Case report and literature review

Introducción: los quistes epidermoides son el tercer tumor más común del ángulo pontocerebeloso (APC). Es infrecuente detectar simultáneamente un colesteatoma infiltrativo del oído medio (OM). Caso clínico: paciente de 51 años acude a urgencias por cefalea hemicraneal intensa, pulsátil secundaria a hidrocefalia aguda, requirió ventriculostomía. En la resonancia magnética nuclear (RMN) cerebral contrastada se reporta una masa en el APC sugestivo de quiste epidermoide y simultáneamente un colesteatoma infiltrativo del OM. La paciente fue intervenida primero con resección de colesteatoma del OM; en un segundo tiempo resección del quiste epidermoide del APC por vía translaberíntica. El posoperatorio la evolución clínica fue satisfactoria. Discusión: los quistes epidermoides del APC son histopatológicamente idénticos al colesteatoma del OM y pueden ser secundarios a estos. Conclusión: se debe individualizar el manejo sin descartar la posibilidad de tener las dos enfermedades de manera simultánea.

Introduction: cysts are the third most common tumor of the cerebellopontine angle (CPA). It is rare to simultaneously detect an infiltrative cholesteatoma of the middle ear (OM). Clinical case: a 51-year-old patient attended the emergency department due to intense throbbing hemicranial headache secondary to acute hydrocephalus, requiring ventriculostomy. Contrast-enhanced cerebral magnetic resonance imaging (MRI) reported a mass in the APC suggestive of an epidermoid cyst and simultaneously an infiltrative cholesteatoma of the OM. The patient underwent first surgery with resection of the OM cholesteatoma; in a second stage, resection of the epidermoid cyst of the APC through a translabyrinthine approach. The postoperative clinical evolution was satisfactory. Discussion: APC epidermoid cysts are histopathologically identical to OM cholesteatoma and may be secondary to them. Conclusion: management must be individualized without ruling out the possibility of having both diseases simultaneously.

Giant perineal epidermoid cyst in adult man: a rare case report and review of literature.

An epidermoid cyst is a common benign cutaneous mass that mostly occurs on the neck, face and trunk. The majority of epidermoid cysts are small and asymptomatic with the giant perineal epidermal cyst being rare and more liable to develop complications such as malignant transformation. The treatment of an epidermal cyst involves total excision of the cyst along with its wall to prevent recurrence. We present an unusual case of a giant perineal epidermal cyst in a 52-year-old male.

Epidermoid cyst beneath the scar after total knee arthroplasty: a case report.

The epidermal cysts are benign cysts most commonly found in the head, neck and trunk. An epidermal cyst of the knee is an unusual complication developed after total knee arthroplasty. Here, we present a case of an 83-year-old man with a palpable mass in the left knee located beneath the scar, 3 years after total knee arthroplasty. The patient underwent complete surgical excision of the mass. Histological analysis revealed an epidermoid cyst.

Parasellar epidermoid cyst with unique radiological features: A case report and review of the literature.

Intracranial epidermoid cysts (ECs) are encapsulated lesions lined by squamous cell epithelium and the most location is the cerebellopontine angle and appears with cerebrospinal fluid-like irregular mass. Occasionally, ECs present as high-density masses on computed tomography and atypical features in magnetic resonance images in the unusual area, which makes the diagnosis difficult. Here, we report a case of a female subject who complained of episodic left facial convulsions for more than 3 months. Computed tomography plain scan revealed a large hyperdense parasellar mass with atypical magnetic resonance findings. In this report, we analyzed retrospectively the radiological characteristics and histopathology of the parasellar EC, thus increasing awareness about this unusual image features.

Corynebacterium guaraldiae sp. nov.: a new species of Corynebacterium from human infections.

Non-diphtheria Corynebacterium species (NDC) belonging to the human skin and mucosa microbiota are frequently neglected as contaminants. However, reports of human infections by Corynebacterium spp. have increased considerably in recent years. In this study, a group of six NDC isolates of urine (n = 5) and sebaceous cyst (n = 1) from two South American countries were identified at genus level or misidentified based on API® Coryne and genetic/molecular analyses. The 16S rRNA (99.09-99.56%) and rpoB (96.18-97.14%) gene sequence similarities of the isolates were higher when compared with Corynebacterium aurimucosum DSM 44532 T. Multilocus sequence analysis (MLSA) indicated that these six NDC isolates compose a distinctive phylogenetic clade. Genome-based taxonomic analysis with the whole-genome sequences was able to separate these six isolates from other known Corynebacterium type strains. Average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridization (dDDH) values between closely related type strains and the six isolates were considerably lower than the currently recommended threshold values for species circumscription. Phylogenetic and genomic taxonomy analyses indicated these microorganisms as a novel Corynebacterium species, for which we formally propose the name Corynebacterium guaraldiae sp. nov. with isolate 13T (= CBAS 827T = CCBH 35012T) as type strain.

Fetal Orbital Epidermal Cyst Pre-postnatal Imaging Findings: A Case Report and Literature Review.

BACKGROUND: Fetal ultrasonographic evaluation is a routine part of pregnancy follow-up, and examination of orbital structures is also part of the routine evaluation. Although orbital developmental anomalies are common in the neonatal period, diagnosis in the intrauterine period is not common. To our knowledge, three cases with a diagnosis of congenital orbital epidermal cysts have been reported in the literature, and two of them had fetal imaging findings. In this article, we present the prepostnatal imaging findings of a case diagnosed with orbital cyst in the fetal period and histopathologically diagnosed as epidermal cyst in the neonatal period. CASE REPORT: A 25-year-old woman applied for ultrasonography (USG) examination at 22 weeks of gestation. A 35x45 mm cystic lesion causing proptosis, without solid component and vascularity, surrounding the optic nerve and causing its thinning was observed in the left orbit. In fetal magnetic resonance imaging (MRI), the intraorbital cystic lesion, which was hyperintense on T2W images and hypointense on T1W images, had no relationship with intracranial structures and no solid component. The lesion of the patient, followed up with a multidisciplinary approach, was shown similarly with computed tomography (CT) and magnetic resonance imaging (MRI) in the postnatal period. Subsequently, the patient underwent globe-sparing surgery, and the pathological diagnosis was made as the epidermal cyst. CONCLUSION: Orbital epidermal cysts are rarely seen, and detection in the fetal period is even rarer. It should be considered in the differential diagnosis of orbital cystic lesions that cause proptosis in fetal and neonatal periods.

Squamous cell carcinoma arising from a huge buttock epidermal cyst without skin lesion: A case report.

INTRODUCTION: Epidermal cysts are common lesions on the surface of the body. However, squamous cell carcinomas (SCCs) arising from epidermal cysts are rare and even rarer without skin lesions, such as ulcers. PRESENTATION OF CASE: A 66-year-old male presented with a 10-cm sized mass on the left buttock without skin lesions. The patient was aware of the existence of the lesion 10 years prior. However, recently, the mass increased in size causing pain. Surgical resection was decided based on the suspicion of an epidermal cyst. Histopathological examination revealed SCC arising from an epidermal cyst. Additional complete resection was performed. No recurrence was observed 1 year after the surgery. DISCUSSION: The clinical and pathophysiological characteristics of malignant transformation of epidermal cysts have not yet been fully elucidated. However, the lesions are characterized by long-lasting and rapid growth later, with the presence of a keratinous cystic tissue structure similar to an epidermal cyst. Part of the tumor is non-malignant, which is adjacent to the area of atypical cell proliferation. The present case had all the above four characteristics and was therefore diagnosed as SCC arising from an epidermal cyst. CONCLUSION: Even if a palpable mass shows benign findings on physical examination, malignant transformation should be considered if the mass grows rapidly in size and is accompanied by symptoms such as pain.