Case report: Uncommon manifestations of Rosai-Dorfman disease in the liver mimicking HCC.

Rosai-Dorfman-Destombes disease (RDD) is a rare non-Langerhans cell histiocytosis (LCH) disorder characterized by systemic extranodal lesions. Common cases include skin lesions, whereas liver lesions are rare. This study presents a case of a 66-year-old woman with a solitary extranodal liver lesion who underwent successful surgical treatment followed by glucocorticoid therapy. The patient did not experience any symptoms before surgery. The liver lesion was incidentally discovered during a routine ultrasound examination. Enhanced CT scan revealed the lesion with the characteristic of washout, similar to primary hepatic cancer (HCC). CT scans of the head, neck, chest, and abdominal pelvis revealed no lymph node or other organ lesions. After surgery, the liver lesion was diagnosed as RDD, and subsequent whole-body examinations did not reveal any skin lesions. The definitive diagnosis was solid liver RDD in adults. Although there were no typical cases of bilateral cervical lymph node lesions, ultrasound and CT examinations promptly detected liver lesions, leading to the correct diagnosis through surgical resection. The findings from this case indicate that RDD can occur in rare extrasegmental areas, and the imaging characteristics of liver lesions are not specific, indicating the importance of avoiding delayed diagnosis.

Cladribine Use in Xanthoma Disseminatum: A Rare Case Presentation and Brief Updated Literature Review.

Xanthoma disseminatum (XD) is a rare, non-Langerhans cell histiocytosis. While treatment is notoriously difficult, 2-chlorodeoxyadenosine (cladribine) has recently emerged as a potential effective therapeutic option. Here, we describe the case of a 65-year-old male with XD who experienced significant cutaneous improvement after cladribine treatment. We also provide an updated literature review on cladribine use in patients with XD in light of reported adverse effects (AEs). While the efficacy of cladribine in XD is clear, no consensus exists for treatment duration and AE management. Hence, we strongly encourage interdisciplinary discourse involving dermatology and oncology in these cases.

Congenital Juvenile Xanthogranuloma in the Perioral Region: A Case Image.

Juvenile xanthogranuloma (JXG) is the most common form of non-Langerhans cell histiocytosis in childhood. It often presents with cutaneous involvement and exhibits a predilection for the head and neck region. This article illustrates a case of congenital JXG in a 5-month-old boy, characterized by a solitary, well-circumscribed nodule above the left upper lip. Histopathologically, the lesion exhibited histiocytes with eosinophilic cytoplasm and Touton giant cells. Immunohistochemistry revealed histiocytes positive for CD68 and Factor XIIIa, while negative for S-100 protein. Clinicians should become familiar with the broad clinical spectrum of cutaneous JXG, particularly its congenital presentation, in order to ensure timely and accurate management.

A rare presentation of Rosai-Dorfman-Destombes disease with central nervous system involvement and cutaneous wounds.

OBJECTIVE: The aim of this case report is to investigate an uncommon presentation of Rosai-Dorfman-Destombes (RDD) disease, and discuss possible differential diagnoses and treatment options for this pathology. RDD is a rare disorder of histiocytes that typically presents in patients as painless cervical lymphadenopathy. However, this case involves a patient with the central nervous system (CNS) type of RDD who later developed cutaneous lesions. METHOD: Several differential diagnoses were examined, including hidradenitis suppurativa, pilonidal cyst and pressure ulcers. It is important to be able to exclude these diagnoses based on the presentation, patient demographic and wound location. RESULTS: Biopsies verified the presence of RDD in the patient's suprasellar hypothalamic mass and skin lesions, confirming the patient had both CNS-RDD and cutaneous-RDD in the absence of lymphadenopathy. CONCLUSION: Recognising the unique manifestations of rare diseases such as RDD prevents delay of proper intervention and treatment.

Adult Onset Orbital Xanthogranuloma, a Variant of Adult Orbital Xanthogranulomatous Disease: An Infrequent Entity.

Adult orbital xanthogranulomatous diseases (AOXGD) present clinically with symmetrical swellings around the eyes and are collectively considered within the broader group of non-Langerhans cell histiocytosis. A 45-year-old female presented with asymptomatic progressive, skin-colored, thick raised lesions around the eyes of 1 year duration. On dermatological examination, large indurated, lobulated, skin-colored thick plaques were seen bilaterally over infraorbital areas, along with a few hard, discrete nodules over the left infraorbital area. Histopathology showed pan-dermal infiltration with foamy histiocytes, non-lipidized histiocytes, a few multinucleate giant cells, lymphocytes, and a few plasma cells, with immunohistochemistry showing CD68 and S100 positivity. Laboratory and imaging studies did not show any abnormality. Based on the above findings and the absence of internal organ involvement, the patient was diagnosed with adult-onset orbital xanthogranuloma (AOX). The patient was treated with three monthly sessions of intralesional corticosteroid injections, along with methotrexate 12.5 mg per week for 8 weeks, resulting in a moderate reduction in the size of the plaques. The patient is under regular follow-up. The present case highlights the rare case of AOX and the importance of prompt recognition and evaluation in view of its potential hematological and systemic associations.

Erdheim-Chester disease with tendon and muscle involvement: Reports of a rare presentation.

Erdheim-Chester disease (ECD) is a rare histiocytic disease that affects multiple systems in the body. While it typically targets long bones, cardiovascular structures, the retroperitoneum, and the central nervous system, reports of tendon and skeletal muscle involvement are scarce. This review presents 2 cases: a case of ECD involving the left Achilles tendon and left abductor hallucis, as well as an unusual manifestation of ECD in the thigh musculature. In Case 1, studies involved a 39-year-old man who initially presented with bone and pituitary involvement. An order for 18F-FDG PET/CT imaging was placed by marked swelling in the patient's left ankle and observed soft tissue fullness on foot radiographs, which revealed a soft tissue mass involving the left Achilles tendon, which arose along the tendon-muscle junction and involved the left abductor hallucis muscle. In Case 2, studies involved a 41-year-old man who initially presented with involvement of the cardiovascular system and retroperitoneum. 18F-FDG PET/CT scan showed an infiltrative right atrial mass and hypermetabolic lesion in the left external obturator muscle, extending to the left pectineus and right quadratus femoris muscle. Involvement of the Achilles tendon and skeletal muscle involvement, including left abductor hallucis muscle and medial thigh muscles, is one of the rare manifestations of ECD. Diagnostic delays were frequent due to the condition's rarity and nonspecific multisystemic symptoms. This should be considered in patients who present with myositis, tendinopathy, and bone pain and have other unexplained multisystemic problems.

Clinicopathological study of ophthalmic cutaneous and mucocutaneous non-langerhans cell histiocytic lesions.

BACKGROUND: The "C group" of the histiocytic disorders is characterized by non-Langerhans-cell histiocytic lesions in the skin, mucosal surfaces, or both, out of which Juvenile xanthogranuloma (JXG) is the most common typically affecting the skin. The eye is the most common extra-cutaneous site of JXG., we aim at providing our clinical and histopathological experience with this group of diseases including the adult-onset xanthogranuloma (AXG). METHODS: This is a retrospective cohort study of all patients with the tissue diagnosis of ocular and periocular cutaneous and mucocutaneous non-LCH disorders who presented to us over a period of 25 years (January 1993 to December 2018). RESULTS: Twenty patients were diagnosed as "Group C" disease with an age range of 2 months-60.9 years. Eleven patients were females (55%) and nine were males (45%). The involvement was mostly unilateral in 80.9%. All cases fell into the xanthogranuloma family with 11 JXG patients, 8 AXG patients of skin and ocular surface, and one patient with solitary reticulohistiocytoma (SRH). The clinical site of involvement in JXG was primarily in the eyelid in 5 patients (45%), ocular surface lesions in 2 (18%), iris in 2 (18%), choroidal and bilateral orbital lesions in 1 patient each (9%). The group of AXG, presented equally with eyelid lesions in 4/8 and ocular surface lesions in 4/8. The non-Langerhans' histiocytic infiltrate showed supportive immunohistochemical staining properties (reactive to CD68 marker and negative to S-100 and langerin markers). CONCLUSION: Among the rare histiocytic disorders, xanthogranulomatosis is the commonest and has wide clinical manifestations. Accurate diagnosis needs to be supported by typical histopathological findings. JXG was the commonest in our study with relatively older mean age at presentation and frequent eyelid rather than iris involvement. AXG is often confused with xanthelasma when involving the eyelids with corneal limbal involvement is relatively frequent.

A Diagnostic Dilemma and Classification Conundrum: Atypical Histiocytic Neoplasm Presenting as a Calvarial Mass.

Histiocytic disorders are a wide range of disorders arising from abnormal proliferation and infiltration of dendritic cells. The Histiocyte Society has arranged the disorders into five main groups: L, C, M, R, and H. We present a case in which an elderly woman presented with a solitary osseous lesion in her skull in the right anterior calvarium. Biopsy and histological studies were strongly positive for cyclin D1; positive for CD68, S100, and ZBTB46; weakly positive for OCT2; and equivocal for ALK1 and CD163. Genomic studies also identified KRAS and GPS2 mutations. KRAS-positive genomic analysis favors a diagnosis of histiocytoma, while the solitary calvarium and spontaneous resolution with remission favor a diagnosis of Langerhans cell histiocytosis (LHC). Despite the strong clinical evidence favoring LCH, our patient's clinical and histologic features did not fit any of the five histiocytic categories and were classified as an atypical histiocytic disorder.

Rosai-Dorfmann Disease: A Rare Disease Presenting as a Unilateral Neck Swelling.

Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disorder of unknown etiology. Usually it presents with massive painless cervical lymph node enlargement. Histologically, it shows proliferation of distinctive histiocytic cells that demonstrate emperipolesis in the background of a mixed inflammatory infiltrates. Immunohistochemically, the cells are positive for markers such as CD68 and S100. A 14-year-old boy presented with painless right sided cervical lymphadenopathy without any systemic and other ear, nose, and throat manifestations. The biopsy report of the lymph node showed infiltration of sheets of histiocytes showing emperipolesis with areas of fibrosis and hyalinisation. The sinus histiocytes were strongly positive for S-100 protein. RDD must be considered in the differential diagnosis of massive or multiple lymphadenopathies.

El papel de la PET/TC con 2-[18F]FDG en la enfermedad de Erdheim-Chester / The role of 2-[18F]FDG PET/CT in Erdheim-Chester disease

Objetivo Analizar la distribución corporal de la enfermedad Erdheim-Chester (ECD) y determinar la utilidad de la 2-[18F]FDG-PET/TC frente a otras técnicas de imagen. Asimismo, evaluar la agresividad y la extensión de la enfermedad según la presencia/ausencia de mutación BRAFV600E. Material y métodos Se revisaron las 2-[18F]FDG-PET/TC de todos los pacientes diagnosticados con ECD entre 2008 y 2021: en total, 19 pacientes. Los territorios afectados se clasificaron como detectables por PET/TC o detectables solamente por otras técnicas de imagen (gammagrafía ósea, TC con contraste yodado o RM). Se realizó análisis descriptivo y correlación de la mutación BRAF con los órganos afectados y SUVmáx mediante la prueba t de Student. Resultados De los 19 pacientes (14 hombres; edad media 60,3años), 11 presentaban la mutación BRAFV600E. Se detectaron un total de 127 territorios (64 órgano-sistemas) afectados utilizando las diferentes modalidades de imagen, de los cuales 112 fueron detectados por la PET/TC y 15 territorios adicionales fueron identificados únicamente por la RM cerebral y cardiaca. La presencia de mutación BRAFV600E se asoció con mayor afectación orgánica (p<0,05), sin diferencias en el SUVmáx (p>0,05). Conclusión La 2-[18F]FDG-PET/TC es una prueba de alto rendimiento diagnóstico en pacientes con ECD, detectando la mayoría de los territorios afectados. La RM fue la única prueba de imagen con hallazgos adicionales en territorios con alta captación fisiológica de 2-[18F]FDG (cerebral y cardíaca). La presencia de mutación del BRAFV600E se correlacionó con mayor extensión de la enfermedad (AU)

Objective To analyze the body distribution of Erdheim-Chester disease (ECD) and determine the utility of 2-[18F]FDG PET/CT compared to other imaging techniques. Additionally, to assess the aggressiveness and extent of the disease based on the presence/absence of the BRAFV600E mutation. Materials and methods The 2-[18F]FDG PET/CT scans of all patients diagnosed with ECD between 2008 and 2021 were reviewed, including 19 patients. The affected territories were classified as detectable by PET/CT or detectable only by other imaging techniques (bone scintigraphy, contrast-enhanced CT, or MRI). Descriptive analysis and correlation of the BRAF mutation with the affected organs and maximum SUV were performed using the Student's t-test. Results Out of the 19 patients (14 males; mean age 60.3years), 11 had the BRAFV600E mutation. A total of 127 territories (64 organ-systems) affected were identified using different imaging modalities, of which 112 were detected by PET/CT, and an additional 15 territories were solely identified by cerebral and cardiac MRI. The presence of BRAFV600E mutation was associated with greater organ involvement (P<.05) without differences in SUVmax (P>.05). Conclusion 2-[18F]FDG PET/CT is a highly effective diagnostic tool in patients with ECD, detecting the majority of affected territories. MRI was the only imaging modality with additional findings in territories showing high physiological uptake of 2-[18F]FDG (cerebral and cardiac). The presence of the BRAFV600E mutation correlated with a higher extent of the disease (AU)

Rare Case of a Patient With Erdheim-Chester Disease Presenting With Atypical Breast Involvement.

Erdheim-Chester disease (ECD) is a rare multisystem disorder characterized by mitogen-activated protein kinase (MAPK) pathway mutations. Herein, we present a unique case of ECD in a 79-year-old female with predominant breast nodules. Comprehensive imaging and histopathological evaluations confirmed the diagnosis. Mammography and ultrasonography revealed multiple hyperdense circumscribed nodules with coalescing masses and blurred margins. Core biopsy revealed infiltrating foamy cluster of differentiation (CD) 68+ and CD1a+ histiocytes. Because the tumor was negative for the BRAF V600E mutation, treatment with interferon-α was initiated. This case highlights the diagnostic challenges associated with ECD, the rarity of breast involvement, and the importance of considering ECD in the differential diagnosis of atypical breast lesions. Comprehensive imaging, histopathology, and genetic testing are essential for accurate diagnosis and treatment decision-making in ECD. Further research and awareness are required to improve recognition and management of this rare disease.

Enfermedad de Rosai-Dorfman cutánea, reporte de un caso / Cutaneous Rosai-Dorfman disease, a case report

RESUMEN La enfermedad de Rosai-Dorfman cutánea (ERDC) es una rara proliferación reactiva de histiocitos, que cursa con lesiones cutáneas sin compromiso generalizado. Las manifestaciones clínicas cutáneas son diversas y la variante clínica "tipo tumoración" es la forma más infrecuente. Se describe el caso de un paciente con ERDC que se presentó con esta forma inusual.

ABSTRACT Cutaneous Rosai-Dorfman disease (CRDD) is a rare reactive histiocytic proliferation, which presents with skin lesions without systemic involvement. The clinical cutaneous manifestations are diverse and the "tumor-like" clinical variant is the most infrequent. We describe the case of a patient with CRDD who presented with this unusual form.

The role of 2-[18F]FDG PET/CT in Erdheim-Chester disease.

OBJECTIVE: To analyze the body distribution of Erdheim-Chester disease (ECD) and determine the utility of 2-[18 F]FDG PET/CT compared to other imaging techniques. Additionally, to assess the aggressiveness and extent of the disease based on the presence/absence of the BRAFV600E mutation. MATERIALS AND METHODS: The 2-[18F]FDG-PET/CT scans of all patients diagnosed with ECD between 2008 and 2021 were reviewed, including 19 patients. The affected territories were classified as detectable by PET/CT or detectable only by other imaging techniques (bone scintigraphy, contrast-enhanced CT, or MRI). Descriptive analysis and correlation of the BRAF mutation with the affected organs and maximum SUV were performed using the Student's t-test. RESULTS: Out of the 19 patients (14 males; mean age 60.3 years), 11 had the BRAFV600E mutation. A total of 127 territories (64 organ-systems) affected were identified using different imaging modalities, of which 112 were detected by PET/CT, and an additional 15 territories were solely identified by cerebral and cardiac MRI. The presence of BRAFV600E mutation was associated with greater organ involvement (p < 0.05) without differences in SUVmax (p > 0.05). CONCLUSION: 2-[18F]FDG PET/CT is a highly effective diagnostic tool in patients with ECD, detecting the majority of affected territories. MRI was the only imaging modality with additional findings in territories showing high physiological uptake of 2-[18F]FDG (cerebral and cardiac). The presence of the BRAFV600E mutation correlated with a higher extent of the disease.

Erdheim-Chester disease with chorioretinal and orbital involvement: a case report / Doença de Erdheim-Chester com envolvimento coriorretiniano e orbitário: relato de caso

ABSTRACT A 42-year-old woman presented with bilateral proptosis, chemosis, leg pain, and vision loss. Orbital, chorioretinal, and multi-organ involvement of Erdheim-Chester disease, a rare non-Langerhans histiocytosis, with a negative BRAF mutation was diagnosed based on clinical, radiological, and pathological findings. Interferon-alpha-2a (IFNα-2a) was started, and her clinical condition improved. However, 4 months later, she had vision loss with a history of IFNα-2a cessation. The same therapy was administered, and her clinical condition improved. The Erdheim-Chester disease is a rare chronic histiocytic proliferative disease that requires a multidisciplinary approach and can be fatal if left untreated because of multisystemic involvements.

RESUMO Uma mulher de 42 anos apresentou proptose bi-lateral, quemose, dor nas pernas e perda de visão. Com base em achados clínicos, radiológicos e patológicos, foi diag-nosticada doença de Erdheim-Chester com acometimento orbitário, coriorretiniano e multiorgânico. Trata-se de uma rara histiocitose não Langerhans negativa para a mutação BRAF. Foi iniciado tratamento com interferon alfa-2a (IFNα-2a) e o quadro clínico melhorou. No entanto, quatro meses depois, a paciente apresentou perda visual após a cessação do IFNα-2a. A mesma terapia foi administrada novamente e sua condição clínica melhorou novamente. A doença de Erdheim-Chester é uma doença proliferativa histiocítica crônica rara que necessita de uma abordagem multidisciplinar e pode ser fatal se não tratada, devido a envolvimentos multissistêmicos.

Recurrent petit mal seizures in Erdheim-Chester disease mimicking an intra-axial brain tumor: illustrative case.

BACKGROUND: Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis characterized histologically by foamy histiocytes and Touton giant cells in a background of fibrosis. Bone pain with long bone osteosclerosis is highly specific for ECD. Central nervous system involvement is rare, although dural, hypothalamic, cerebellar, brainstem, and sellar region involvement has been described. OBSERVATIONS: A 59-year-old man with a history of ureteral obstruction, medically managed petit mal seizures, and a left temporal lesion followed with serial magnetic resonance imaging (MRI) presented with worsening seizure control. Repeat MRI identified bilateral amygdala region lesions. Gradual growth of the left temporal lesion over 1 year with increasing seizure frequency prompted resection. A non-Langerhans cell histiocytosis with a BRAF V600E mutation was identified on pathology. Imaging findings demonstrated retroperitoneal fibrosis and long bone osteosclerosis with increased fluorodeoxyglucose uptake that, together with the neuropathologic findings, were diagnostic of ECD. LESSONS: This case of biopsy-proven ECD is unique in that the singular symptom was seizures well controlled with medical management in the presence of similarly located bilateral anterior mesial temporal lobe lesions. Although ECD is rare intracranially, its variable imaging presentation, including the potential to mimic seizure-associated medial temporal lobe tumors, emphasizes the need for a wide differential diagnosis.

Malignus emlotumor? Gyulladásos emloelváltozás? Ritka benignus kórkép?

Case-report: Rosai-Dorfman disease, also known as sinus histiocytosis with massive lymphadenopathy is a rare, benign non-Langerhans cell histiocytosis, that typically involves the lymph nodes, but may also involve extranodal sites. We present a 58- years- old female patient who complained of a palpable mass in her left breast surrounded by 15-20 livid cutaneous lesions, resembling malignant breast cancer with cutaneous metastasis. Despite of core biopsy of the tumor and excisional biopsy one of the lesions, correct diagnosis of RDD was achieved only by complete pathological examination of the whole lesion after surgical excision. Conclusion: Rosai-Dorfman disease confined to the breast is extremely rare, that clinically may mimic breast cancer.