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Competing Interests: The authors declare no conflicts of interest.

Cutaneous pseudolymphomas are a wide group of diseases mimicking cutaneous lymphoma. They comprise several skin conditions with different etiopathogenesis, clinical-pathological features, and prognosis, which may occur in the absence of an identifiable trigger factor or after administration of medications or vaccinations, tattoos, infections, or arthropod bites. They present with different manifestations: from solitary to regionally clustered lesions, up to generalized distribution and, in rare cases, erythroderma. They persist variably, from weeks to years, and resolve spontaneously or after antibiotics, but may recur in some cases. CD30+ T-cell pseudolymphomas are characterized by the presence of large, activated lymphoid cells, generally in response to viral infections, arthropod assault reactions, and drug eruptions. Stenotrophomonas maltophilia is a ubiquitous Gram-negative bacillus responsible for opportunistic infections in immunocompromised patients. Infection of intact skin in immunocompetent patients is particularly rare. Here, we report a case of a man presenting an isolated nodule histopathologically mimicking a primary cutaneous CD30+ T-cell lymphoproliferative disorder., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The popularity of tattoos has led to an increase in associated skin reactions, including complications such as infection, allergic reactions and rare conditions such as tattoo-induced cutaneous lymphoid hyperplasia (CLH). CLH is a benign lymphoproliferative reaction with clinical features resembling malignant cutaneous lymphomas. Non-invasive diagnostic tools like reflectance confocal microscopy (RCM) and the new line-field confocal optical coherence tomography (LC-OCT) are being studied in dermatology better to understand the morphological patterns of many dermatological diseases. Between September 2021 and May 2023, patients with suspicious lesions for tattoo-related CLH were analysed using RCM and LC-OCT before confirming the diagnosis of CLH through skin biopsy and histopathological examination. The study included five cases of CLH. It focused on the analysis of high-quality LC-OCT images/videos and RCM images to investigate the features of CLH in tattooed individuals. Most (80%) cases exhibited a mixed T and B lymphocyte infiltration subtype, while 20% showed a predominant T infiltration subtype. RCM and LC-OCT revealed characteristic features, including architectural disarray, fibrosis, lymphoid infiltrates, and pigment deposits in the epidermis and dermis. Non-invasive tools such as RCM and LC-OCT are valuable in diagnosing tattoo-related CLH. While skin biopsy remains the current standard for diagnosis, RCM and LC-OCT can serve as helpful adjuncts in identifying the most representative area for biopsy. They may potentially become alternative diagnostic options in the future, offering benefits in terms of cost, diagnostic efficiency, aesthetics and patient satisfaction as the prevalence of tattoo-related adverse reactions continues to rise., (© 2024 Australasian College of Dermatologists.)

Duodenal type follicular lymphoma (DFL), a rare entity of follicular lymphoma (FL), is clinically indolent and is characterized by a low histological grade compared with nodal follicular lymphoma (NFL). Our previous reports revealed that DFL shares characteristics of both NFL and mucosa-associated lymphoid tissue (MALT) lymphoma in terms of clinical and biological aspects, suggesting its pathogenesis may involve antigenic stimulation. In contrast to NFL, the genomic methylation status of DFL is still challenging. Here, we determined the methylation profiles of DNAs from patients with DFL (n = 12), NFL (n = 10), duodenal reactive lymphoid hyperplasia (D-RLH) (n = 7), nodal reactive lymphoid hyperplasia (N-RLH) (n = 5), and duodenal samples from normal subjects (NDU) (n = 5) using methylation specific PCR of targets previously identified in MALT lymphoma (CDKN2B/P15, CDKN2A/P16, CDKN2C/P18, MGMT, hMLH-1, TP73, DAPK, HCAD). DAPK1 was frequently methylated in DFL (9/12; 75%), NFL (9/10; 90%), and D-RLH (5/7; 71%). CDKN2B/P15 sequences were methylated in six DFL samples and in only one NFL sample. Immunohistochemical analysis showed that p15 expression inversely correlated with methylation status. Genes encoding other cyclin-dependent kinase inhibitors (CDKN2A/P16, CDKN2C/P18) were not methylated in DFL samples. Methylation of the genes of interest was not detected in DNAs from D-RLH, except for DAPK1, and the difference in the extent of methylation between NDU and D-RLH was statistically significant (P = 0.013). Our results suggest that D-RLH serves as a reservoir for the development of DFL and that methylation of CDKN2B/P15 plays an important role in this process.

Background: Hepatic reactive lymphoid hyperplasia (RLH) is a rare benign lymphoproliferative lesion and a poorly understood disease. It is usually asymptomatic and incidental, but it is difficult to distinguish from hepatocellular carcinoma and metastatic liver tumor on imaging, and percutaneous biopsy is not sufficient to distinguish from low-grade malignant lymphoma and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), making diagnosis difficult., Case Summary: A 69-year-old woman came to our hospital for reexamination of pulmonary nodules followed by liver occupation. The lesions showed "wash-in and wash-out" on contrast-enhanced ultrasonography and magnetic resonance imaging. Enhanced magnetic resonance also showed annular envelope enhancement and limited diffusion on the ADC map during the delay period. Imaging revealed metastatic liver cancer, and the patient underwent a partial hepatectomy. However, the final histopathological diagnosis was RLH., Conclusion: If small isolated nodules are found in the liver of middle-aged and elderly female patients with no risk factors for liver malignancy, when the enhanced imaging suggests "wash-in and wash-out", further focus should be placed on whether the enhanced imaging shows perinodular enhancement and whether the DWI shows limited diffusion in MRI, in order to emphasize the possibility of liver RLH diagnosis.

Introduction: Lymphadenopathy is usually due to benign or malignant conditions. It can also be local or systemic in distribution and can involve peripheral or deep-seated lymph nodes. This study aimed to determine the prevalence of lymphoma and the distribution pattern of lymph node pathologies among adult patients who presented with lymphadenopathy and its relationship with age and sex., Methods: A retrospective study was conducted, and a record of all cases of lymphadenopathy with histological diagnosis over 5-year period (January 2017 to December 2021) was extracted from Departments of Anatomical Pathology of Alex Ekwueme Federal University Teaching Hospital, Abakaliki. The data generated were analyzed using Statistical Package for Social Sciences (SPSS) software, version 26., Results: One hundred and ninety results were extracted with an age range of 18 to 94 years and a mean age of 41 ± 16 years. They were made up of 75 (39.5%) males and 115 (60.5%) females, with a male-to-female ratio of 1:1.5. The prevalence of lymphoma was 50.0% (95/190). Thirty-five (18.4%) were Hodgkin's lymphoma (HL), while 60 (31.6%) were non-Hodgkin's lymphoma (NHL). Other pathologies manifested by cases of lymphadenopathy include metastatic tumor deposits (38 (20%)), reactive lymphoid hyperplasia (29 (15.3%)), and tuberculous lymphadenitis (18 (9.5%)). Others include sinus histiocytosis (4 (2.1%)), dermatopathic lymphadenitis (5 (2.6%)), and Castleman's disease (1 (0.5%))., Conclusion: About half of all patients who presented with lymphadenopathy were lymphoma with a high prevalence of 50%, and the majority were NHL. Other major causes of lymphadenopathy were metastatic tumor deposits, reactive lymphoid hyperplasia, and tuberculous lymphadenitis. Any case of lymphadenopathy should be properly investigated early for effective management., (Copyright © 2024 Copyright: © 2024 Nigerian Journal of Clinical Practice.)

Background: Primary cutaneous CD4 + small/medium-sized pleomorphic T-Cell lymphoproliferative disorder (PC-SMTLD) has been considered as a controversial dermatological disease that has been included in cutaneous T-cell lymphoma group, presenting most commonly as a solitary nodule and/or plaque with a specific and characteristic head and neck predilection. Due to the considerable overlap between PC-SMTLD and pseudolymphoma (PL), the differential diagnosis is often challenging. Methylation of DNA at position 5 of cytosine, and the subsequent reduction in intracellular 5-hydroxymethylcytosine (5-hmC) levels, is a key epigenetic event in several cancers, including systemic lymphomas. However, it has rarely been studied in cutaneous lymphomas., Objectives: The authors aimed to explore the role of differential 5-hmC immunostaining as a useful marker to distinguish PC-SMTLD from PL., Methods: Retrospective case series study with immunohistochemical and immunofluorescence analysis of 5-hmC was performed in PL and PC-SMTLD., Results: Significant decrease of 5-hmC nuclear staining was observed in PC-SMTLD when compared with PL (p < 0.0001). By semi-quantitative grade integration, there were statistical differences in the final 5-hmC scores in the two study groups. The IF co-staining of 5-hmC with CD4 revealed a decrease of 5-hmC in CD4 + lymphocytes of PC-SMTLD., Study Limitations: The small clinical sample size of the study., Conclusions: The immunorreactivity of 5-hmC in CD4 + lymphocytes was highly suggestive of a benign process as PL. Furthermore, the decrease of 5-hmC nuclear staining in PC-SMTLD indicated its lymphoproliferative status and helped to make the differential diagnosis with PL., (Copyright © 2023 Sociedade Brasileira de Dermatologia. Published by Elsevier España, S.L.U. All rights reserved.)

A 70-year-old woman was referred to our hospital because of slight elevation of soluble interleukin-2 receptor (sIL-2R) and accumulation of 18F-fluorodeoxyglucose (FDG) in S8 of the liver on positron emission tomography. The mass was strongly suspected to be malignant because of contrast enhancement and enlargement in size of the mass, and suspicion of portal vein invasion. Hepatic S8 subsegmentectomy was performed for diagnostic and therapeutic purposes. Hematoxylin and eosin staining of the resected specimen showed small lymphocytes with no atypia and no formation of lymphoid follicles. Immunostaining showed CD3-positive cells in the interfollicular region and CD20-positive cells in the lymphoid follicles. Both CD10 and BCL-2 were negative in the follicular germinal center. CD138-positive plasma cells were observed and there was no light chain restriction. Based on polyclonal growth pattern of lymphocytes in the lymphoid follicles and interfollicular region, she was diagnosed with hepatic reactive lymphoid hyperplasia (RLH).Review of the English literature of hepatic RLH which referred to imaging findings yielded 23 cases, including this case. As a result, we suggest that liver biopsy should be performed for definitive diagnosis, when hepatic RLH is suspected by imaging findings and backgrounds., (© 2023. Japanese Society of Gastroenterology.)

Hepatic reactive lymphoid hyperplasia is an uncommon benign condition, often found incidentally as a solitary liver lesion. The chronic inflammatory reaction associated with autoimmune conditions and malignancies has been postulated as a possible aetiology. The diagnosis is challenging as it often mimics various malignancies radiologically and histologically, hence the diagnosis being made only after surgical resection. Lymphadenopathy is common with primary biliary cholangitis, though rarely reported with reactive lymphoid hyperplasia. We report a case of hepatic reactive lymphoid hyperplasia associated with portacaval lymphadenopathy in a patient with primary biliary cholangitis, diagnosed after surgical resection. We propose lesional biopsy be considered in patients with primary biliary cholangitis found to have a solitary lesion with supporting low-risk clinical and radiological features., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

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BACKGROUND Jessner's lymphocytic infiltration of the skin (JLIS) is a rare and benign process of unknown cause. This disorder affects both sexes, most commonly in the young adult population. However, the demographic characteristics remain largely unknown, due to limited information. JLIS clinical presentation is heterogeneous; lesions can be indurated papular or erythematous plaques on the upper body. Symptoms are variable, from asymptomatic to pruritus and burning sensation. CASE REPORT A female patient aged 73 years presented with 10-day asymptomatic dermatosis on the left malar area after an insect sting. At the beginning, the lesion was clinically classified as an abscess and antibiotic therapy was prescribed with ciprofloxacin 500 mg every 12 hours for 5 days. However, due to the lack of clinical response, a biopsy was performed, which reported a predominantly lymphocytic nodular dermatitis. JLIS diagnosis was confirmed after laboratory and imaging tests. Intralesional infiltrations of triamcinolone (0.5 ml) twice within 15 days and mineral sunscreen 3 times a day were prescribed. After the treatment, the lesion had a complete resolution without recurrence to date. CONCLUSIONS The present case reports JLIS in an older woman who presented a complete healing resolution of the lesion without recurrences after triamcinolone intralesional infiltrations and sunscreen protection.

Abstract: Primary cutaneous marginal zone lymphoma (PCMZL) is a low-grade malignant B-cell lymphoma that originates from the skin. It often presents as erythematous solitary or multiple papules, nodules, and/or plaques. It is one of the 3 main subtypes of primary cutaneous B-cell lymphomas. PCMZLs are believed to develop from chronic antigenic stimulation such as from tick-borne bacteria, vaccines, tattoo pigment, or other foreign body. In addition, cutaneous lymphoid hyperplasia, a documented precursor to malignant PCMZL, often presents in response to areas of chronic inflammation. Cutaneous lymphoid hyperplasia and PCMZL share several clinical and histological similarities that require clinicopathologic suspicion, immunohistochemical ancillary studies, and histopathologic analysis to accurately differentiate the 2 entities. Although gene rearrangement studies have historically been of limited value in the diagnosis of PCMZL, recent studies investigating molecular markers have identified the presence of multiple genetic abnormalities that have helped to better characterize the disease and aid in diagnosis. In addition, newer studies have found associations between PCMZL and gastrointestinal disorders, including Helicobacter pylori and inflammatory bowel disorders. In this article, we describe a case of a 56-year-old patient with a history of ulcerative colitis presenting with chronic reactive lymphoid hyperplasia that transformed to primary cutaneous marginal zone lymphoma., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Pseudolymphoma is a rare, benign, nonspecific condition that forms a mass-like lesion characterized by the proliferation of non-neoplastic lymphocytes. Lacking of specific clinical symptoms, serological markers, and imaging features, the diagnosis is difficult. We reporte five cases of hepatic pseudolymphoma and provide a systematic review of existing literatures to improve our understanding of this rare liver disease., Methods: We followed-up five cases of hepatic pseudolymphoma in West China Hospital from January 2002 to January 2022. We also summarized the cases of hepatic pseudolymphoma from January 1981 to December 2021 through the PubMed database and comprehensively analyzed the characteristics of the cases., Results: The pathologic features of the five cases were characterized by benign lymphoid tissue hyperplasia, lymphoid follicle formation, and a polarized germinal center. Immunohistochemistry, in situ hybridization, and gene rearrangement revealed non-malignant lymphoma. Besides, a total of 116 cases have been reported in the PubMed database from 1981 to 2021. The incidence of hepatic pseudolymphoma is higher in middle-aged and elderly women and has been reported more frequently in Asia. All cases were pathologically diagnosed, among which 85.95% of the patients were treated by surgery., Conclusions: Hepatic pseudolymphoma is an extremely rare benign disease, mainly in middle-aged and elderly women. Without distinctive clinical and imaging characteristics, pathological diagnosis is the highly reliable method at present. Thus, in the absence of risk factors for a primary liver tumor or metastatic tumor in middle-aged and elderly women, the possibility of pseudolymphoma should be considered to avoid extensive treatments., Competing Interests: Declaration of competing interest The authors disclose no conflicts., (Copyright © 2023 Asian Surgical Association and Taiwan Robotic Surgery Association. Published by Elsevier B.V. All rights reserved.)

Cutaneous pseudolymphomas (CPL) is a group of benign, reactive, and polyclonal lymphoproliferative dermatoses that simulate cutaneous lymphomas (CL) clinically and histologically. Based on the predominating component of lymphocytic infiltrate, CPL can be divided into cutaneous B-cell pseudolymphomas (CBPL), cutaneous T-cell pseudolymphomas (CTPL), mixed (T-/B-cell) pseudolymphomas, CD30-positive pseudolymphomas, and non-classifiable pseudolymphomas. Most patients with localized nodular CBPL present with a solitary nodule. However, few patients develop multiple skin lesions, rarely in generalized forms. Here we describe a rare case of multiple nodular CBPL on both sides of the patient's neck, which was treated successfully with intramuscular injection of compound betamethasone, oral methotrexate, and hydroxychloroquine for 4 months. No recurrence was observed in the patient at the one-year follow-up. This combined treatment may be a promising treatment choice for multiple nodular CBPL., (© 2022 Wiley Periodicals LLC.)

Cutaneous lymphoid hyperplasia (CLH), also known as cutaneous pseudolymphoma, is a spectrum of benign conditions characterized by reactive B- and T-cell cutaneous lymphocytic infiltrates. B-cell lymphoid proliferations are a heterogenous group of non-neoplastic cutaneous diseases that must be histopathologically distinguished from cutaneous B-cell lymphomas. These proliferations can be observed as reactive phenomena to infections, medications, allergens, neoplasms, and more. Furthermore, there are many inflammatory conditions that present with reactive B-cell infiltrates, including actinic prurigo, Zoon balanitis, Rosai-Dorfman disease, and cutaneous plasmacytosis. This review summarizes multiple cutaneous B-cell lymphoid proliferations within the major categories of reactive and disease-associated CLH. Further we discuss major discriminating features of atypical CLH and malignancy. Understanding the specific patterns of B-cell CLH is essential for the proper diagnosis and treatment of patients presenting with such lesions., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To investigate the clinicopathological features of adult orbital xanthogranulomatous disease (AOXGD) with lacrimal gland reactive lymphoid hyperplasia. Methods: Retrospective case series study. The clinical and pathological data of AOXGD cases diagnosed and treated in Tianjin Eye Hospital from January 2002 to December 2021 was reviewed, and the clinical characteristics, radiologic findings and pathological characteristics of periocular and lacrimal gland lesions of 5 cases were retrospectively analyzed. The expression of IgG4 and IgG protein in periocular and lacrimal gland lesions was detected by immunohistochemical staining, and the role of IgG4 in AOXGD was preliminarily studied. Results: There were four females and one male with an average age of 53.8 years (39 to 77 years). Among the five AOXGD cases, there were three cases of adult-onset xanthogranuloma, one case of adult-onset asthma and periocular xanthogranuloma, and one case of necrobiotic xanthogranuloma. All cases involved both eyes. The swelling of eyelids was observed in five cases, and the yellow or pale yellow eyelid skin was found in two cases. Imaging examinations showed the tumor mainly involved the eyelids, subcutaneous tissues, anterior orbit and lacrimal gland. A large number of foam cells and typical Touton giant cells were found in the periorbital lesions, accompanied by different degrees of fibrosis. The fibrinoid necrosis was detected in one case of necrobiotic xanthogranuloma. The lacrimal gland lesions showed different types of reactive lymphoid hyperplasia, including IgG4-related disease in two cases, follicular lymphoid hyperplasia in two cases and focal lymphoid hyperplasia in one case. IgG4 levels of periorbital and lacrimal gland lesions were elevated in four cases. Asthma and elevated serum IgG4 were found in one case of adult-onset periocular xanthogranuloma. Three patients underwent surgical resection and adjuvant hormone or immunosuppressive therapy, and two patients underwent simple surgical resection. The patients were followed up for 1.5 to 10.0 years, one patient was lost, and four patients had no recurrence. Conclusions: AOXGD with lacrimal gland reactive lymphoid hyperplasia is a group of rare diseases. The periorbital lesions of that are characterized by proliferation of foamy histiocytes and Touton giant cells, and the lacrimal gland lesions of that manifest as IgG4-related disease in some cases.

Background: Cutaneous pseudolymphoma (CPL) refers to a group of benign, reactive processes that mimic cutaneous lymphoma and are associated with a variety of triggering immune stimuli, including arthropod bites, drugs, and foreign bodies. In children, most cases of CPL are due to a variant of Borreliosis that is specific to Eurasia. Cutaneous pseudolymphoma secondary to ear piercing has only been documented in adults. Case Reports : We present the clinical and pathological findings of cutaneous Bcell psuedolymphoma in two adolescent patients (11-year-old female and 15-year-old male) secondary to ear piercing. Conclusion : Our report expands the clinico-pathological spectrum of CPL associated with ear piercing by documenting its occurrence in children.

Abstract: Cutaneous lymphoid hyperplasia (CLH) is a benign reactive process with T-cell or B-cell lymphocytic infiltration in the skin, which can simulate cutaneous lymphomas both clinically and histologically. Various antigenic stimuli have been implicated in the development of CLH, including tick bites. Finding histologic evidence of such triggering factors, however, is often difficult. Moreover, the presence of clonality in CLH can potentially be interpreted as a neoplastic process, posing a further diagnostic challenge to dermatopathologists, if one is not aware of such peculiar phenomena. Herein, we describe a case of CLH secondary to a tick bite, featuring both T-cell clonality and monotypic plasma cells with lambda light chain restriction; the diagnostic clue being tick parts, which became evident on assessment of deeper levels. To the best of our knowledge, this is the first reported case of a tick-associated clonal CLH with simultaneous detection of monoclonal T cells and monotypic lambda light chain restriction, mimicking primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder and Borrelia-associated primary cutaneous marginal zone B-cell lymphoma, respectively., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Pseudolymphoma of the liver (Reactive Lymphoid Hyperplasia) (RLH) is a rare condition. It is usually asymptomatic and detected incidentally on radiological imaging. Imaging features are similar to hepatic adenoma, hepatocellular carcinoma, cholangiocarcinoma, and malignant lymphoma and are not specific for pseudolymphoma of the liver. Percutaneous core biopsy is insufficient to distinguish pseudolymphoma of the liver from low-grade malignant lymphoma and extranodal marginal lymphomas., Case Descriptions: In this article, we present a case of hepatic RLH of a patient who was presented with a skin rash on the leg and was detected incidentally on radiological imaging., Conclusion: Preoperative definitive diagnosis of hepatic RLH using various imaging methods, including MRI with hepatocellular agents, is highly difficult., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Abstract: We describe a rare case of cutaneous pseudolymphoma with Langerhans cell hyperplasia. An 84-year-old female patient presented with erythematous and pernicious-looking plaques on her scalp that had been present for months. Histologically, lymphoid follicles consisting of mixed-type lymphocytes and Langerhans cells were aggregated focally. The diagnosis was verified by several immunohistochemical stains and by clinical evaluation. Skin lesions were steadily resolved with low-dose corticosteroid and hydroxychloroquine., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Pulmonary nodular lymphoid hyperplasia, also known as pseudolymphoma, is an uncommon reactive lymphoproliferative disorder of unknown etiology that can be found in Sjögren's syndrome patients. Here, we present a case of a previously healthy woman in which the incidental finding of a lung mass compatible with nodular lymphoid hyperplasia led to the subsequent diagnosis of Sjögren's syndrome. We also performed a literature review for the association between both entities and described the main clinical aspects of the reported cases. Although its rarity, we consider that pulmonary nodular lymphoid hyperplasia should be considered in the differential diagnosis of lung nodules or masses among Sjögren's syndrome patients., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Subcutaneous vaccination or desensitization may induce persistent nodules at the injection sites. Without the knowledge of prior injection, histopathological work-up may be challenging., Objective: Aim of this study was to contribute to the histopathological work-up of unclear subcutaneous nodules, especially their differentiation from cutaneous lymphoma., Methods: We retrospectively reviewed clinical data and histopathological slides of four patients with subcutaneous nodules, which were suspected to suffer from cutaneous T- or B-cell lymphoma. Sections of these cases and 12 negative controls were stained with hematoxylin and eosin and a standardized immunohistochemical panel of B- and T-cell markers including EBER in situ hybridization as well as electron microscopy., Results: In all cases, large histiocytes with granular cytoplasm compatible with intracellular aluminum hydroxide were present. EBER in situ hybridization revealed positive staining of these granular histiocytes while staining was absent in negative controls., Limitations: Post hoc completion of medical history revealed that vaccination or specific immunotherapy had been applied before at the biopsy site in only three out of four patients; one patient was lost to follow-up., Conclusion: EBER in situ hybridization is an adjunctive tool to differentiate aluminum-induced granuloma/lymphoid hyperplasia from other forms of pseudolymphoma and cutaneous B- or T-cell lymphomas., (© 2021 The Authors. Journal of Cutaneous Pathology published by John Wiley & Sons Ltd.)

Intracranial pseudolymphoma is a rare entity. We report the case of a 44 year old female who presented with headaches and was noted to have a right lateral ventricular lesion on a background history of Burkitt's lymphoma. She underwent biopsy of said lesion and was found to have benign reactive lymphoid tissue. This is the third reported case in literature of intracranial pseudolymphoma and the first reported intraventricular lesion., (Crown Copyright © 2020. Published by Elsevier Ltd. All rights reserved.)

Objectives: To establish a diagnostic tree analysis (DTA) model based on ultrasonography (US) findings and clinical characteristics for differential diagnosis of common causes of cervical lymphadenopathy in children., Methods: A total of 242 patients (131 boys, 111 girls; mean age, 11.2 ± 0.3 years; range, 1 month-18 years) with pathologically confirmed Kikuchi disease (n = 127), reactive hyperplasia (n = 64), lymphoma (n = 24), or suppurative lymphadenitis (n = 27) who underwent neck US were included. US images were retrospectively reviewed to assess lymph node (LN) characteristics, and clinical information was collected from patient records. DTA models were created using a classification and regression tree algorithm on the basis of US imaging and clinical findings. The patients were randomly divided into training (70%, 170/242) and validation (30%, 72/242) datasets to assess the diagnostic performance of the DTA models., Results: In the DTA model based on all predictors, perinodal fat hyperechogenicity, LN echogenicity, and short diameter of the largest LN were significant predictors for differential diagnosis of cervical lymphadenopathy (overall accuracy, 85.3% and 83.3% in the training and validation datasets). In the model based on categorical parameters alone, perinodal fat hyperechogenicity, LN echogenicity, and loss of fatty hilum were significant predictors (overall accuracy, 84.7% and 86.1% in the training and validation datasets)., Conclusions: Perinodal fat hyperechogenicity, heterogeneous echotexture, short diameter of the largest LN, and loss of fatty hilum were significant US findings in the DTA for differential diagnosis of cervical lymphadenopathy in children., Key Points: • Diagnostic tree analysis model based on ultrasonography and clinical findings would be helpful in differential diagnosis of pediatric cervical lymphadenopathy. • Significant predictors were perinodal fat hyperechogenicity, heterogeneous echotexture, short diameter of the largest LN, and loss of fatty hilum.

We describe an otherwise healthy 24-year-old woman with reactive lymphoid hyperplasia of one lacrimal gland. She was found to have modest elevation of serum IgG4 and high density of IgG4+ plasma cells in her lacrimal gland, ranging from 40% to 60% of IgG+ plasma cells. The patient transiently responded to systemic corticosteroids before treatment with rituximab. IgG4-rich reactive lymphoid hyperplasia of the lacrimal gland is neither an established part of IgG4-related disease spectrum nor a known precursor lesion to lymphoma. Although there is a plausible risk of transforming to IgG4-related disease or to lymphoma, the biological potential and natural history of IgG4-rich reactive lymphoid hyperplasia remains to be determined.

We report an unusual case of drug-associated granulomatous CD30 + T-cell pseudolymphoma secondary to amlodipine. A 55-year-old Chinese man presented with a 6-month eruption of disseminated erythematous dermal papulonodules and annular infiltrated plaques over his neck and limbs symmetrically. Histopathology revealed a perivascular and interstitial infiltrate of histiocytes, eosinophils and morphologically normal lymphocytes associated with CD30 expression. The eruption improved rapidly after discontinuation of amlodipine and did not recur., (© 2020 The Australasian College of Dermatologists.)

Background: The purpose of the study was to discuss the effectiveness of mediastinoscopy for pediatric patients as the use of EBUS-EUS (Endobronchial Ultrasound-Endoscopic Ultrasound) has replaced mediastinoscopy for adult patients in evaluation of the mediastinal area., Methods: The records of patients subject to cervical and anterior mediastinoscopy at our clinic from January 1, 2000 to June 1, 2019 were examined and patients aged 18 years or less were included in the study. Data were acquired on the demographic characteristics of the patients, type of surgery, complications, operation times, and histopathologic diagnoses., Results: Of the 1505 patients subject to intervention by mediastinoscopy at our clinic from January 1, 2000 to June 1, 2019, only 22 (1.46%) were pediatric patients aged 18 years or less. Cervical and anterior mediastinoscopies were performed on 16 and six patients, respectively. Histopathological tissue diagnoses via mediastinoscopy were obtained for 19 (86.3%) of 22 patients. The most frequently observed diagnoses were sarcoidosis (n = 10), lymphoma (n = 4), thymoma (n = 1), tuberculosis (n = 1), undifferentiated round cell sarcoma (n = 1), and reactive lymph node (n = 2); three patients could not be diagnosed. Mortality was not detected. There were no major complications requiring thoracotomy or sternotomy and none of the patients were subject to tube thoracostomy as a result of surgery., Conclusion: Pediatric age mediastinoscopy may be the first method of diagnosis due to low complication rates and high diagnosis rates in mediastinal area., (Copyright © 2019. Published by Elsevier Taiwan LLC.)

Pseudolymphomatous folliculitis is a benign entity that is included within pseudolymphomas. Because of its rapid clinical growth and suspicious histology it has to be differentiated from malignant entities. Given its low frequency, the dermatoscopic characteristics of this entity are not well-characterized and have been described only once previously. We present a middle-aged woman with a facial erythematous plaque of 6 months' evolution, with dermatoscopy in which follicular plugs on an erythematous base were appreciated. The histology showed a dense lymphocytic infiltrate with folliculotropism and follicular alteration, with numerous peripheral histiocytes positive for S100 and CD1a. The lesion partially disappeared after the biopsy, and completely after topical treatment.

Cutaneous reactions to tattoos are increasing as the prevalence of tattoos increases. Lichenoid reactions often occur in red tattoos and are usually localised to the tattoo. We present a case of recurrent lichenoid reaction occurring in both the black tattooed and adjacent non-tattooed skin., (© 2019 The Australasian College of Dermatologists.)

A 39-year-old Japanese woman presented with a pruritic infiltrated erythematous plaque on the right cheek. Histopathologic analysis of the erythema showed dermal edema, separation of collagen bundles, and nodular perivascular and periadnexal infiltration of lymphocytes in the whole dermis, without epidermal changes. Alcian blue staining intensity was elevated between the collagen bundles, indicating dermal mucinosis. The nodular infiltrates consisted of CD3+ T cell clusters and CD20+ B cell clusters (ratio, approximately 3:1) and included numerous CD123+ cells, indicative of plasmacytoid dendritic cells. Blood analysis revealed serum antinuclear antibody at a titer of 1:160 (homogeneous, speckled pattern). Lupus erythematosus tumidus with pseudolymphomatous infiltrates was diagnosed. Hydroxychloroquine treatment partially improved symptoms; however, the addition of prednisolone was required for complete resolution. Lupus erythematosus tumidus is sometimes accompanied by pseudolymphomatous infiltrates. Dermal mucinosis and the presence of numerous plasmacytoid dendritic cells are useful in differentiating lupus erythematosus tumidus from pseudolymphoma.

Cutaneous pseudolymphomas (PSLs) belong to a group of lymphocytic infiltrates that histopathologically and/or clinically simulate lymphomas. Different causative agents (e.g., Borrelia sp., injected substances, tattoo, arthropod bite) have been described, but in many cases no cause can be identified, hence the term idiopathic PSL. Clinicopathological correlation is important to make the diagnosis. Four main groups of cutaneous PSL can be distinguished based on histopathologic and/or clinical presentation: (a) nodular PSL; (b) pseudo-mycosis fungoides (pseudo-MF) and simulators of other CTCLs; (c) other PSL (representing distinct clinical entities); and (d) intravascular PSL. This article gives an overview of the histopathologic and clinical characteristics of cutaneous PSLs and proposes a new classification., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)