Benign liver tumors in pediatric patients-Review with emphasis on imaging features

Benign hepatic tumors are commonly observed in adults,but rarely reported in children.The reasons for this remain speculative and the exact data concerning the incidence of these lesions are lacking.Benign hepatic tumors represent a diverse group of epithelial and mesenchymal tumors.In pediatric patients,most benign focal liver lesions are inborn and may grow like the rest of the body.Knowledge of pediatric liver diseases and their imaging appearances is essential in order to make an appropriate differential diagnosis.Selection of the appropriate imaging test is challenging,since it depends on a number of age-related factors.This paper will discuss the most frequently encountered benign liver tumors in children(infantile hepatic hemangioendothelioma,mesenchymal hamartoma,focal nodular hyperplasia,nodular regenerative hyperplasia,and hepatocellular adenoma),as well as a comparison to the current knowledge regarding such tumors in adult patients.The current emphasis is on imaging features,which are helpful not only for the initial diagnosis,but also for pre- and posttreatment evaluation and follow-up.In addition,future perspectives of contrast-enhanced ultrasound(CEUS) in pediatric patients are highlighted,with descriptions of enhancement patterns for each lesion being discussed.The role of advanced imaging tests such as CEUS and magnetic resonance imaging,which allow for non-invasive assessment of liver tumors,is of utmost importance in pediatric patients,especially when repeated imaging tests are needed and radiation exposure should be avoided.

Endoscopic ultrasound elastography: current status and future perspectives

Elastography is a new ultrasound modality that provides images and measurements related to tissue stiffness. Endoscopic ultrasound(EUS) has played an important role in the diagnosis and management of numerous abdominal and mediastinal diseases. Elastography by means of EUS examination can assess the elasticity of tumors in the proximity of the digestive tract that are hard to reach with conventional transcutaneous ultrasound probes, such as pancreatic masses and mediastinal or abdominal lymph nodes, thus improving the diagnostic yield of the procedure. Results from previous studies have promised benefits for EUS elastography in the differential diagnosis of lymph nodes, as well as for assessing masses with pancreatic or gastrointestinal(GI) tract locations. It is important to mention that EUS elastography is not considered a modality that can replace biopsy. However, it may be a useful adjunct, improving the accuracy of EUSfine needle aspiration biopsy(EUS-FNAB) by selecting the most suspicious area to be targeted. Even more, it may be useful for guiding further clinical management when EUS-FNAB is negative or inconclusive. In the present paper we will discuss the current knowledge of EUS elastography, including the technical aspects, along with its applications in the differential diagnosis between benign and malignant solid pancreatic masses and lymph nodes, as well as its aid in the differentiation between normal pancreatic tissues and chronic pancreatitis. Moreover, the emergent indication and future perspectives are summarized, such as the benefit of EUS elastography in EUS-guided fine needle aspiration biopsy, and its uses for characterization of lesions in liver, biliary tract, adrenal glands and GI tract.

Ultrasonographic imaging of inflammatory bowel disease in pediatric patients

Inflammatory bowel disease(IBD) is one of the most common chronic gastrointestinal diseases in pediatric patients.Choosing the optimal imaging modality for the assessment of gastrointestinal disease in pediatric patients can be challenging.The invasiveness and patient acceptance,the radiation exposure and the quality performance of the diagnostic test need to be considered.By reviewing the literature regarding imaging in inflammatory bowel disease the value of ultrasound in the clinical management of pediatric patients is highlighted.Transabdominal ultrasound is a useful,noninvasive method for the initial diagnosis of IBD in children;it also provides guidance for therapeutic decisions and helps to characterize and predict the course of the disease in individual patients.Ultrasound techniques including color Doppler imaging and contrast-enhanced ultrasound are promising imaging tools to determine disease activity and complications.Comparative studies between different imaging methods are needed.

Kinetics and FTIR characteristics of the pyrolysis process of poplar wood

The pyrolysis characteristics of residues of poplar （Populus sp.） wood were investigated using a thermogravimetric analyzer coupled with a Fourier transform infrared （TG-FTIR） spectrometer. The pyrolysis process was sub- divided into four stages at a rate of 10℃.min-1, varying from 30 to 650℃. Below 180℃, a mass loss occurred for drying and preheating the sample and the onset temperature of pyrolysis ranged between 180-260℃. A significant mass loss 3f 61.4 wt.% occurred between 260-380℃, followed by a slow and continuous mass change with lignin devolatilization. The analysis of kinetic reactions showed that the activation energy （78.29 kJ.mol-1） in the low-temperature section was much larger than that （6.40 kJ-mol-1） in the high-temperature section. The evolved gases formed by thermal degradation 3f poplar wood were simultaneously analyzed by FTIR. It was observed from the main peaks that the emissions evolved during poplar wood pyrolysis were acetic acid, carbon dioxide, carbon monoxide, methane, water, some volatile com- 3ounds of esters, alcohols and aldehydes. The emissions gradually increased with rising temperatures before a strong 3eak around 360℃ and then decreased. Most gaseous products were emitted in the 320-380℃ range, while CO2 was =ontinuously emitted in a wide range from 140-550℃.

Major Clinical Features and Epidemic Characteristics of Erosive Vulvar Lichen Planus:A Retrospective Analysis

Objective:Vulvar lichen planus(VLP),especially erosive VLP(EVLP),seriously affects women’s physiological function and quality of life.A retrospective analysis of erosive vulvar lichen planus(EVLP)was performed to raise awareness on this chronic,deforming,and painful vulvar disease.Methods:This observational retrospective study involved 40 patients with EVLP among 1,368 patients with vulvar disease from 2017 to 2020.The patients’vulvar clinical features and extravulvar mucosal involvement were investigated.The patients’pain and quality of life were evaluated with the numeric rating scale and the Dermatology Life Quality Index(DLQI),respectively.Clinical characteristics were reported using frequencies and proportions for categorical variables.Continuous variables are expressed as mean±standard deviation.The association between NRS score for pain and DLQI score was analyzed by Pearson’s correlation test.Results:EVLP accounted for 2.9%(40/1,368)of all cases of vulvar disease,and the median age at onset was 42 years.Erosion mostly occurred on the labia minora and introitus.Half(20/40)of the patients had extravulvar mucosal involvement.Seventeen(42.5%)patients had oral lichen planus,and seven(17.5%)patients were diagnosed with vulvovaginal-gingival syndrome.The numeric rating scale score showed that 47.5%(19/40)of patients experienced mild pain,whereas 12.5%(5/40)described the pain as severe.Thirty-one patients(77.5%,31/40)had dyspareunia,and nine patients had aggravated pain after sexual intercourse.The mean DLQI score was 9.1±6.0,with 37.5%(15/40)of patients indicating that EVLP had severely affected their lives.The numeric rating scale score for pain was significantly correlated with the DLQI score(P=0.007).Conclusion:EVLP can affect the quality of women’s lives and cause severe deformations and painful architectural changes.The description of the characteristics of EVLP in this report will benefit the diagnosis and early treatment of this disease.

Liponeurofibroma

A liponeurofibroma is a dermal neurofibroma(NF)with an infiltration of abnormal fat cells.Under HE staining,the liponeurofibroma lesion is a well-circumscribed and nonencapsulated tumor mass located in the dermis.Spindle-shaped tumor cells with wavy cytoplasm and elongated nuclei are scattered in the tumor mass.Fatty change is clearly seen inside the tumor,replacing the Sshaped cells.Round fat cells with vacuolated cytoplasmand thin nuclei are larger than the surrounding cells and may gather and fuse into clusters,while some adipocytes have intraluminal flap-like structures(Fig.1).

Piloleiomyoma

Histopathology Cutaneous piloleiomyoma(PLM),angioleiomyoma,and genital leiomyoma are variants of superficial cutaneous leiomyoma(CL).The classic appearance of a CL on hematoxylin and eosin staining is an unencapsulated,circumscribed dermal tumor composed of interlacing fascicles of spindle cells with a moderate amount of eosinophilic cytoplasm and a blunt-ended,elongated,cigar-shaped nucleus with perinuclear halos on crosssection;there is sometimes nuclear pleomorphism or a small number of mitoses,but the tumor retains its benign character(Fig.1A).

Retiform Hemangioendothelioma

Histopathology Histopathological examination is required to confirm the diagnosis of retiform hemangioendothelioma(RH)because RH does not have distinctive clinical features.Histopathological examination reveals arborizing blood vessels in the dermis,extending between the collagen bundles in a reticular fashion and flanked by lymphocytes and hyaline sclerosis.The vessels are lined by monomorphic endothelial cells with scanty cytoplasm and prominent protuberance of the nucleus.

A Study of Normal Epidermal Melanocyte Distribution

Objective:To elucidate the epidermal melanocyte distribution according to sex,age,and body part with the goal of providing benchmark data for the diagnosis and therapeutic effect evaluation of pigmentary skin diseases.Methods:Epidermal melanocytes and keratinocytes were assessed using direct immunofluorescence staining,and the melanocyte density and epidermal thickness were calculated.The obtained data were statistically analyzed using SPSS Version 20.0 software.An independent-samples t test was used to compare the data between two groups,while data among three or more groups were compared by one-way analysis of variance.Data correlations were evaluated using Pearson correlation analysis.Results:Melanocytes were uniformly distributed among the keratinocytes in the basal layer,and the average ratio of melanocytes to keratinocytes was 1:7.Among them,the ratio in males was 1:6.5 and that in females was 1:7.4,with no significant difference(P=0.127).The melanocyte density gradually declined as age increased;the ratio was 1:5.8 before 50 years of age without an obvious downtrend.The average melanocyte density was 1:7.9 within 51 to 65 years of age and 1:8.5 at>65 years of age,and the difference was statistically significant(P<0.01).Obvious differences were found in the melanocyte density among different body parts;in descending order,these densities were as follows:face(1:4.0)>neck(1:5.1)>hip(1:5.7)>upper limb(1:7.4)>lower limb(1:8.3)>lower back(1:9.2)>thorax and abdomen(1:9.9).The melanocyte density was not related to the epidermal thickness.Conclusion:The melanocyte density showed a declining trend with age and significantly changed after 50 years of age.The melanocyte density was associated with body part;specifically,the density in the face,neck,and hip was higher than that in the limbs and torso.However,the melanocyte density was not associated with sex or epidermal thickness.

Calcified Epidermal Cyst on the Neck

Histopathology Histological examination of a calcified epidermal cyst reveals a dermal cystic structure.In addition to laminated layers of keratinous material,the cavity is filled with amorphous basophilic calcareous sediment(Fig.1A).The cyst wall consists of thinned stratified squamous epithelium similar to the hair follicle infundibulum,which is surrounded by fibrosis(Fig.1B).Active inflammation is sometimes seen around the cyst.The etiology and pathogenesis of these pathological findings are controversial.

Solid-Cystic Hidradenoma

Histopathology Solid-cystic hidradenoma (SCH) is located in the dermis and can be attached to the epidermis or extend into the subcutaneous tissue.The lesion is well circumscribed with clear edge.It can be encapsulated or unencapsulated.There were both a large cavity and a solid component in the tumor.The cyst is lined by flattened or cubic secretory cells,while the cystic wall is more often constituted by tumor cells.Therefore,the cystic cavity may be caused by the necrosis of tumor cell.The cysts consist of uniformly eosinophilic materials.The tumor cells were characteristic of slightly basophilic cytoplasm and round nuclei.Most SCH have a duct-like structure,which consists of a monolayer of cubical cells with eosinophilic walls (Fig.1A-1C).Tumor lobules are surrounded by collagen fibers,blood vessels,and other interstitium,which sometimes have transparent degeneration.

Black heel

Black heel is also known as'calcaneal petechiae',which is caused by a repeated lateral force on the epidermis sliding over the rete arteriosum of the papillary dermis.It was first reported in players of a basketball team,and appears predominantly in adolescents or young adults,who play sports accompanied with frequent quick starts,stops,and turns of feet,such as tennis,basketball,football,and others[1].

Differences of clinical features between familial and sporadic cases of vitiligo: a hospital-based study

Objective To study the clinical differences between familial and sporadic cases of vitiligo.Methods Clinical data of 1,136 Chinese vitiligo patients in the Department of Dermatology in Beijing Hospital from January 2015 to December 2017 were obtained by questionnaire and statistically analyzed by SPSS 22.0 software.Results Among 1,136 patients enrolled,233 cases (20.5%) had family history of vitiligo.The mean age at onset of vitiligo cases with family history was 24.45 ± 15.87 years old,and was significantly lower than that of sporadic cases,which was 28.12 ± 16.88 years old (P < 0.05).The skin lesions distributed bilaterally in 71.3% of familial vitiligo cases and 60.8% of sporadic cases (P < 0.05),respectively.The difference on the clinical classification between the familial cases and sporadic cases was insignificant (P > 0.05).Conclusion Our study found that vitiligo patients with family history showed significant differences on the mean age at onset of disease and the distribution of skin lesions,which should be further studied in a wider population.

Reactive perforating collagenosis

Histological features of reactive perforating collagenosis (RPC) vary according to stage of disease.The pathological manifestations of lesions that did not form an umbilical fossa in the early stages,degenerate collagen fibers accumulate in dermal papillae and epidermal hyperplasia may be seen.The upper epidermis is atrophied,and a thin layer of keratinized material is visible in the center.Typical acanthosis is visible on both sides of the lesion.In the late stage,epidermis cup-shaped depression can be seen in the epidermis,and it filled with columnar overlying keratin plug that consists of parakeratotic debris,denatured collagen fibers and inflammatory cells[1].The epidermis below is obviously thin.It is locally visible that degenerative collagen fibers pass through the epidermi vertically.The epidermis on both sides of the cup-shaped structure show acanthosis and hyperkeratosis,and infiltration of lymphoid cells is observed in the superficial dermis and around the blood vessels (Figure 1).Blue-stained collagen fibers are visible in the superficial dermis and epidermis in Masson staining.

Epithelioid Blue Nevus

Histopathology Epithelioid blue nevus(EBN)is a tumor with indistinct boundaries located in the dermis(Fig.1A).EBN can penetrate the fat layer,and often affects the appendages.Variably sized spherical cells and polygonal cells are present in the spaces between collagenous fibers.1 Spherical cells have evident pigmentation,a bubble-shaped nucleus,and an obvious nucleolus.Polygonal cells show little pigmentation,but also have a bubble-shaped nucleus and an evident single nucleolus(Fig.1B and 1C).Scattered mitosis is sometimes observed.

Deep Penetrating Nevus

Histopathology The deep penetrating nevus(DPN)is mostly intradermal nevus,and a few are compound nevus.Under low magnification,the DPN shows a wedge-shaped growth pattern:The broad base parallel to the epidermis and the apex penetrate into the deep reticular dermis and fat(Fig.1).At higher magnification,tumor cells are identified as melanocytes that mainly locate in the dermis,generally without involvement of the dermal papilla not affected(Fig.2A).

Urticarial Vasculitis of the Legs

Histopathology Histopathologic examination of urticarial vasculitis (UV) reveals leukocytoclastic vasculitis.Inflammation occurs perivascularly and within the walls of the capillaries and postcapillary venules.The inflammatory infiltrate predominantly comprises neutrophils,although eosinophils and lymphocytes may be present.

Chronic erythematous condition of legs

Histopathology A histopathological examination of skin lesions in mild cases of erythrocyanosis only show lymphocytic infiltration in the upper dermis. In severe cases, dilation of shallow capillaries, endothelial swelling, extravasation of erythrocytes, and occasionally throm-bosis in capillaries can also be found. In this case we described here, the epidermis did not show any abnormal features. The dermis showed dilatation of capillaries and perivascular lymphocytic infiltration (Figure 1).

Hidroacanthoma simplex

From the low-power biopsy specimen,we found hyperkeratosis and acanthosis with some lymphocytes which looks like Seborrheic Keratosis (SK) (Figure 1).At high-power,we observed well-circumscribed intraepidermal nests of clear-looking basaloid cells within the confines of an acanthotic epidermis (Figure 2),and the tumor cells were small and relatively monomorphic,cellular and nuclear atypia was not prominent (Figure 3).Finally,we made the diagnosis of hidroacanthoma simplex.Smith & Coburn first introduced the term hidroacanthoma simplex in 1956 to refer to an intraepidermal variant of poroma[1].The histopathologic findings of hidroacanthoma simplex are cuboidal or ovoid deratinocytes with a vesicular nucleus within an acanthotic epidermis arranged in well-circumscribed intraepidermal nests,with or without presence of the ductal and cystic space.