Generalized Eruptive Histiocytosis or Juvenile Xanthogranuloma: A Clinicopathological Conundrum of Coexistence or Xanthomatization.

Diseases under the non-Langerhans cell histiocytosis (LCH) group often share clinical and histological similarities, making proper delineation highly challenging. A two-year-old female child presented with multiple, small raised asymptomatic lesions all over the body for one year. Cutaneous examination showed multiple brownish flat-topped and yellowish-brown dome-shaped papules scattered all over the body with hyperpigmented macules over the face. A provisional diagnosis of generalized eruptive histiocytosis (GEH) was made. But the dermoscopy and histopathological examination of flat-topped and dome-shaped papules showed features suggestive of generalized eruptive histiocytosis and juvenile xanthogranuloma (JXG) respectively, with a few overlapping features. Systemic examination was found to be normal. Hence an overlap of GEH and JXG was considered, with a thought of ongoing xanthomatization of GEH lesions. The transformation of GEH into xanthoma disseminatum, multicentric reticulohistiocytosis, progressive nodular histiocytosis, and juvenile xanthogranuloma (JXG) has been reported. It has also been reported that GEH and JXG, the two entities that belong to a continuous spectrum of histiocytoses with xanthogranulomatous pathology, can rarely co-exist in the same individual. The distinction between GEH and JXG is crucial, as they may require different management strategies. Our case stresses the fact that relying only on clinical diagnosis can be deceiving owing to the overlapping clinical, dermoscopic, and histopathological features of histiocytoses.

Erdheim-Chester disease: An elusive diagnosis in a 50-year-old Ethiopian man presenting with diffuse sclerotic bone lesion.

Key Clinical Message: Diagnosis of Erdheim-Chester disease (ECD) requires the clinician to be familiar with its various manifestations, classic radiologic and histologic features. This case highlights the significance of considering ECD in any patient presenting with bone pain and symmetric osteosclerosis of long bones of extremities to allow for early diagnosis and treatment. Abstract: Erdheim-Chester disease (ECD) is a rare non-Langerhans histiocytic disorder with diverse clinical manifestations, ranging from indolent, localized presentation to life-threatening, multi-systemic disease. Delayed or erroneous diagnosis is common. The presence of classic radiographic finding along with foamy histiocytes that is positive for CD68 but negative for CD1a on histologic examination establishes the diagnosis. We report a second case of ECD from Ethiopia. A 50-year-old Ethiopian man presented with a 13-year history of bilateral lower leg bone pain, cold intolerance, somnolence, constipation, impotence, decreased libido, and secondary infertility. The diagnosis was suspected when skeletal X-ray revealed bilateral symmetric sclerosis of metadiaphysis of femur, tibia, and humerus. The demonstration of foamy histiocytes that were positive for CD68 but negative for CD1a on histologic examination with immunohistochemical staining confirmed the diagnosis. Evaluation for the extent of the disease revealed coated aorta sign, hairy kidney sign, and cystic lesion with ground glass opacity of lung, primary hypothyroidism, and hypergonadotropic hypogonadism. ECD is rare histiocytic neoplasm with wide range of clinical features which often delay the diagnosis. Clinician should be mindful of the various presentations and the classic radiographic and histologic features of ECD. This case highlights the significance of entertaining ECD in any patient presenting with lower leg bone pain and symmetric osteosclerosis of long bones of lower extremities to allow for early diagnosis and treatment.

A Systematic Review of Clinical Features and Treatment Outcomes of Xanthoma Disseminatum.

Xanthoma disseminatum (XD) is a rare normolipidemic mucocutaneous xanthomatosis within the spectrum of cutaneous non-Langerhans histiocytosis. Managing XD poses substantial challenges, with limited available data. This study aims to comprehensively evaluate existing literature on clinical features of XD and treatment outcomes. A systematic search of MEDLINE, Embase, and PubMed was performed, using "xanthoma disseminatum" and "Montgomery syndrome" as search terms, without restrictions. Screening was performed in duplicate by 2 reviewers. One hundred fifty-one studies met the inclusion criteria, yielding 166 cases of XD (106 females, 60 males), mean age at diagnosis 35.3 years (range: 9 months-87 years). XD typically presented as yellow-to-brown coalescing papules/plaques and nodules. Distribution affects mainly the face (n = 116/166), flexures (n = 45/166), trunk (n = 65/166), and genitalia/inguinal areas (n = 63/166). Most cases (99.4%; n = 165/166) exhibited extracutaneous manifestations, including the pituitary gland and the oropharynx. Treatment options rendered low complete response rates (CRRs). Treatments with reported outcomes included surgical resection (n = 17/99), systemic steroids (n = 40/99), immunosuppressants/immunomodulators (n = 73/99), energy-based devices (n = 7/99), lipid-lowering agents (n = 24/99), cryotherapy (n = 6/99), lasers (n = 10/99), topical steroids (n = 6/99), oral retinoids (n = 2/99), and radiotherapy (n = 5/99), with CCRs of 23.5% (n = 4/17), 5.0% (n = 2/40), 9.6% (n = 7/73), 14.3% (n = 1/7), 4.2% (n = 1/24), 16.7% (n = 1/6), 10.0% (n = 1/10), 0% (n = 0/6), 0% (n = 0/2), and 0% (n = 0/5), respectively. The most promising therapy is cladribine, with the highest CRR of 27.1% (n = 6/22) and the lowest no response rate (9.1%; n = 2/22) of all reported treatments. This review confirms the high prevalence of systemic manifestations in XD. Treatment options vary widely; thus, further research is needed to establish management strategies for this challenging condition.

Remission of necrobiotic xanthogranuloma after intravenous immunoglobulin interruption: A case report.

Necrobiotic xanthogranuloma is a rare non-Langerhans cell histiocytosis with the potential for multisystemic involvement. It's a challenging disease to treat and multiple treatments have been reported in the literature with variable results. We present the case of a 92-year-old woman with multiple orange-brown papules and plaques on her face progressing for several years. The biopsy showed dermal xanthogranulomatous infiltration with multinucleated giant cells and necrobiosis, and she was diagnosed with necrobiotic xanthogranuloma. A complete response was obtained with intravenous immunoglobulins and she remained in remission despite treatment discontinuation.

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.

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.

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.

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.

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.

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.

Multicentric Reticulohistiocytosis-A rare and disabling disease.

Multicentric reticulohistiocytosis is a rare multisystemic condition associated with papulonodular skin lesions, severe arthritis and malignancy. Histopathology shows histiocytes containing abundant eosinophilic ground glass cytoplasm and multinucleated giant cells. Early recognition, age-appropriate malignancy work-up and treatment is important to prevent impairment of daily life activity.

A Case of Rosai-Dorfman Disease Presenting as an Isolated Pleural Plaque.

Rosai-Dorfman disease (RDD) is a rare non-Langerhans histiocytic disorder primarily involving lymph nodes. Extranodal RDD has a heterogenous presentation, and isolated pulmonary involvement is rare. We report the only case of RDD presenting as an isolated pleural mass. Our patient was a 55-year-old female with multiple comorbidities who presented with chest pain. Imaging revealed an enlarging pleural-based lesion. She underwent resection of the pleural mass, showing an atypical histiocytic infiltrate in a prominent background of collagenous fibrosis. Immunohistochemistry shows CD1a-negative and S100-positive atypical histiocytic cells demonstrating emperipolesis, confirming the diagnosis of RDD. She is currently on six-month CT surveillance with no recurrence of the disease. This case highlights the unique pulmonary presentation of RDD. It also underscores that observations may be appropriate in isolated asymptomatic pleural involvement cases.

Rare Cutaneous Manifestations of Erdheim Chester Disease: A Case Report and Literature Review.

Erdheim Chester disease (ECD) is a rare and complex non-Langerhans histiocytic systemic disease that affects multiple organ systems, including the bones, heart, lungs, and central nervous system. Fewer than 1,000 cases have been reported in the medical literature and dermatological manifestations of the disease are rare but can provide valuable diagnostic clues for this challenging disease. The cutaneous manifestations of ECD can take many forms, including nodules, plaques, papules, and xanthomas. These lesions can occur on any part of the body and may be solitary or multiple. Cutaneous manifestations of ECD have been reported to occur in up to 20% of cases, but the true prevalence may be higher, as many cases may go undiagnosed. We present the case of a 62-year-old gentleman with a history of ECD currently on vemurafenib who presented with multiple painless subcutaneous nodules on his back after an excision biopsy under local anesthetic revealed histological features of ECD. The objective of this case report is to raise awareness of ECD and its dermatological manifestations. Further research is warranted to better understand the pathogenesis and morphology of cutaneous involvement in ECD.

Erdheim-Chester disease with bilateral orbital masses and multi-systemic symptoms: two case reports.

BACKGROUND: Erdheim-Chester disease (ECD) is a rare histiocytic disorder characterized by multisystem xanthogranulomatous infiltration by lipid-laden histiocytes. We report two cases of ECD involving the orbit and describe their clinicopathologic factors, treatments, and prognosis. One was a rare case of ECD complicated with primary thrombocytosis. CASE PRESENTATION: This study describes two patients with bilateral orbital ECD. Both presented with proptosis and visual loss; imaging findings showed bilateral intraorbital masses. Both had different degrees of systemic symptoms (pleural effusion, pericardial effusion, ascites, and heart failure) before the ocular symptoms and did not find the cause before ophthalmic tumor resection and pathological biopsy. The diagnosis of ECD was confirmed after pathological biopsy and detection of BRAFV600E mutation. Patient 2 also with primary thrombocytosis and had a CALR mutation as well as the BRAFV600E mutation. Both patients were recommended to receive targeted therapy. Patient 1 refused targeted therapy for financial reasons and was discharged after local radiotherapy only. The patient had no light perception in either eye and no improvement in systemic symptoms. Patient 2 began targeted treatment after diagnosis and reached the discharge criteria 2 weeks later. He is in good condition at present, but unfortunately, his eyesight has not improved because of the irreversible damage to his visual function. CONCLUSION: ECD is easily misdiagnosed and missed because of its rarity and diverse clinical manifestations. Orbital involvement is common in ECD, and surgery is the most frequently employed approach. Despite the surgical resection is not curative, its significance lies in biopsy to establish diagnosis and/or surgical debulking to relieve mass effect, minimizing further impairment of visual function. Targeted therapy is the most effective treatment for patients with a positive BRAF mutation gene. Evaluation of a concomitant myeloid neoplasm is also critical before initiating targeted therapies for refractory ECD.

The value of 18F-FDG PET/CT in the systemic evaluation of patients with Rosai-Dorfman disease: a retrospective study and literature review.

BACKGROUND: Rosai-Dorfman disease (RDD) is a rare form of non-Langerhans cell histiocytic disease. The aim of this study was to review the characteristics of RDD using 18F-FDG PET/CT and determine its efficacy in the disease management. RESULTS: A total of 28 RDD patients underwent 33 18F-FDG PET/CT scans for systematic assessment and follow-up. The common involved sites included the lymph nodes (17, 60.7%), upper respiratory tract (11, 39.3%), and skin (9, 32.1%). Five patients had more lesions detected in PET/CT images than in CT and/or MRI, including inapparent nodules (n = 5) and bone destruction (n = 3). After thorough treatment evaluation using PET/CT, the treatment strategies of 14 patients (14/16, 87.5%) were changed. Five patients underwent PET/CT twice during follow-up and the SUVs were significantly decreased (15.3 ± 3.4 vs. 4.4 ± 1.0, p = 0.02), which demonstrated disease improvement. CONCLUSIONS: 18F-FDG PET/CT contributed to displaying the holistic characteristics of RDD, in particular during initial assessment, treatment strategy adjustment, or efficacy evaluation, and could compensate for some disadvantages of CT and MRI images.

A Case of Multiple Self-Involuting, Mixed Presentation, Giant Congenital Juvenile Xanthogranuloma.

Juvenile xanthogranuloma (JXG) is an uncommon benign skin disorder of infants and young children characterized by dermal proliferation and infiltration of dendrocytes. We present a unique case of giant congenital JXG with a mixed presentation of macules, papules, nodules, and ulcerations in a neonatal male who was observed until the age of 23 months, by which time all lesions had spontaneously self-involuted. Prior to complete resolution, some lesions took the form of pedunculated protrusions. To our knowledge, this is the first of this atypical case to be presented in the literature.