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.

Apparently isolated CNS involvement in Erdheim-Chester disease: Case report

We present the case of a 48-year-old-woman with apparently isolated central nervous system Erdheim-Chester disease characterized by brainstem involvement. Erdheim-Chester disease is extremely rare and multisystem impairment should always be sought in the suspicion of such pathology.

Sinonasal and ear manifestations of Erdheim-Chester disease

To calculate the prevalence of sinonasal and ear involvement in an Erdheim-Chester disease (ECD) population, to describe the different ear, nose and throat (ENT) manifestations and to study the association between ENT involvement, other organ involvement, and BRAF mutations. We led a retrospective monocentric study in the national referral center for ECD. One hundred and sixty-two patients with ECD and ENT data were included between January 1, 1980 and December 31, 2020. Ear and nose clinical and radiological findings were noted. We described and studied the prevalence of ENT involvement in ECD population. The association between sinonasal and ear involvement, other organ involvement, and BRAF mutations was calculated. The prevalence of ENT manifestations is around 45%. No clinical rhinologic or otologic signs were specific to ECD. Sinus imaging was abnormal in 70% of cases. A bilateral maxillary sinus frame osteosclerosis was highly specific of ECD. Associations were found between the sinus MRI imaging type and BRAF status, central nervous system involvement, cerebellum involvement and xanthelasma. Sinonasal or ear involvement is frequent in ECD and has specific imaging features for sinuses. Trial registration: #2011-A00447-34.

[Histiocytosis]

Histiocytosis is a group of rare diseases characterized by inflammation and accumulation of cells derived from monocytes and macrophages in different tissues. The symptoms are highly variable, from mild forms with involvement of a single organ to severe multisystem forms that can be life compromising. The diagnosis of histiocytosis is based on the clinic, radiological findings and pathological anatomy. A biopsy of the affected tissue is recommended in all cases as it may have therapeutic implications. During the last decade, some mutations have been identified in the affected tissue that condition activation of the MAPK/ERK and PI3K/AKT pathway, in a variable proportion depending on the type of histiocytosis. In this review we mainly focus on Langerhans Cell Histiocytosis, Erdheim-Chester Disease and Rosai-Dorfman Disease.

[Combined histiocytosis of the Langerhans group (Langerhans cell histiocytosis and Erdheim-Chester disease) in a 64-year-old man with BRAF and NRAS mutations: a case report]

We present a case of a 64-year-old male with a history of Crohn's disease who presented with an episode of acute abdominal pain. He was being investigated for a dermatological lesion. A skin and lung biopsy both revealed histiocytosis of the "L" (Langerhans) group. The skin biopsy showed a proliferation of histiocytic cells expressing Langerin, CD1a and S100 and the molecular study was positive for the BRAF p.V600E mutation. In the lung biopsy, a proliferation of histiocytic cells was found, which were positive for CD68 and S100 and negative for Langerin and CD1a; mutations in NRAS c.38G>A in exon 2 (p.G13D) were also detected.

A recurrent pleuropneumonia revealing Erdheim-Chester Disease

Erdheim-Chester disease (ECD) is a rare form of L group histiocytosis, accounting for up to 1500 cases to date worldwide, which mainly affects men between their 5th and 7th decade of life. The most frequent manifestations are bone involvement, perirenal infiltration with an evocating appearance of "hairy kidneys", and a "coated aorta" aspect. Lung involvement in ECD is less common and includes pleural infiltration and interstitial lung disease. Herein, we report the case of a 76-year-old woman with recurrent pleuropneumonia revealing ECD.

[Pelvic mass in 70 years old patient: Difficult diagnosis of Erdheim-Chester disease]

Erdheim-Chester disease (EC) is a rare disease that is included in Group L in the 2016 revised classification of Langheransian histiocytoses. This disease may be clinically asymptomatic or manifest as a multi-systemic and life-threatening condition. All organs can be affected but typically there is bone involvement, retroperitoneal fibrosis, pituitary involvement, involvement of large vessels, lung, pleura or central nervous system. We are reporting a 70-year-old patient who, as of 2014, had a pelvic mass with retroperitoneal fibrosis and large vessel vasculitis without a definite diagnosis. Histological and molecular examination of the surgical specimen of the pelvic mass with the discovery of the BRAF V600E mutation provided new elements for the definitive diagnosis of Erdheim-Chester disease. We will describe the clinical, histological and molecular features to be known in EC disease.

A cytologic diagnosis of BRAFV600E Erdheim-Chester disease on pericardial fluid

We report the case of a 74-year-old woman admitted to the emergency unit for resting dyspnea. Clinical presentation, cardiac MRI and echocardiography were consistent with cardiac tamponade requiring emergency pericardiocentesis. Cytologic examination of the pericardial fluid revealed the presence of CD68^pos CD1a^neg S100^neg foamy histiocytes (Fig. 1). Additional investigations complied with the diagnosis of Erdheim-Chester histiocytosis. Treatment with αIFN was initiated but the patient developed severe neutropenia that contraindicated further administration. The detection of BRAF^V600E mutation on histiocytes isolated from the pericardial liquid and CNS involvement (cerebral masses) prompted the administration of vemurafenib, a selective BRAF^V600E kinase inhibitor. Four months after the initiation of low-dose vemurafenib, pericarditis almost resolved and cerebral masses decreased by 50% (Fig. 2). To our knowledge, analysis of pericardial fluid allowing the diagnosis of Erdheim-Chester disease and the detection of the BRAF^V600E mutation has in fact been rarely described in the literature. This case report and the successful evolution under vemurafenib also support the use of BRAF^V600E inhibitors in αIFN-intolerant patients with BRAF^V600E mutation, particularly in case of heart and central nervous system involvement.

BRAF V600E mutation in pediatric intracranial and cranial juvenile xanthogranuloma

Juvenile xanthogranuloma (JXG) is a cutaneous form of non-Langerhans cell histiocytosis, primarily affecting children. The lesion is presumed to originate from either macrophages or dermal dendritic cells. JXG can rarely present as an isolated intracranial lesion and, in contrast to the dismal outcome of patients with systemic disease, cranial JXG has been shown to carry a more favorable prognosis. Here, we report for the first time 3 pediatric cases of JXG with a BRAF V600E mutation, 2 with intracranial lesions and 1 with cranial lesions. Although these intracranial/cranial lesions have been referred to as JXG, they likely differ from cutaneous JXG in both the clinical features and BRAF status. It may be more appropriate to classify intracranial/cranial JXG in the same group as Langerhans cell histiocytosis and Erdheim-Chester disease, which also have a BRAF V600E mutation. Further study of BRAF status in a larger series of JXG is warranted.

Erdheim-Chester disease with orbital involvement: Case report and ophthalmic literature review

Erdheim-Chester disease (ECD) is a rare xanthogranulomatous disease in which orbital involvement can have devastating outcomes. Through a case report and review of the ophthalmic literature, we explore orbital findings, disease progression, and treatment options. Cases of orbital involvement in Erdheim-Chester disease were identified in the ophthalmic literature with a PubMed query and review of cited references. A total of 14 publications reporting 19 separate cases that included ophthalmic examination data were identified. Patient ages ranged from 26-77 years with a mean age of 50 years. Seventy-four percent (14/19) were men. Vision progression to no light perception was found in 32% (6/19) of the patients. Reviewed cases reported a variety of medical and surgical treatment approaches, however, only 53% reported cases (10/19) demonstrated disease improvement or stabilization. Erdheim-Chester disease with orbital involvement is a devastating disease with a poor prognosis. Awareness of this entity by the ophthalmologist is important as orbital signs and symptoms may manifest early, and orbital biopsy is often crucial to the definitive diagnosis.

Erdheim-Chester disease: description of eight cases

Erdheim-Chester disease, although rare, has a wide range of manifestations. It is characterized by the xanthomatous infiltration of tissues by spumous histiocytes, surrounded by fibrosis. The symptoms can vary from bone pain, diabetes insipidus, exophthalmos, xanthelasmas, cardiovascular involvement, bilateral adrenal enlargement, renal impairment, testis infiltration, interstitial lung disease to retroperitoneal fibrosis with perirenal and/or ureteral obstruction. We present eight cases, four of them with only breast involvement and the others with bone, cardiovascular, central nervous system, and renal involvement. All showed infiltrates of histiocytes and fibrosis on microscopic evaluation and positive CD68 and negative CD1a on immunohistochemical stains.

Efficacy of zoledronic acid in Erdheim-Chester disease: A case report

Erdheim-Chester disease is rare form of non-Langerhans cell histiocytosis characterized by organ infiltration of CD68+ CD1a- histiocytes. Between 500 and 600 cases have been reported. It is a multifaceted disease ranging from a solely asymptomatic bone to a fatal multisystem pattern. Bone involvement occurs in more than 90% of cases. Although not life-threatening, bone localizations can be responsible of difficult-to-treat pain and disability. Treatment depends on lesion severity. Bisphosphonates have been reported to be efficient and safe in bone involvement. We report a case of a biopsy proven bone Erdheim-Chester disease in a 65-year-old woman with history of breast cancer. Her pain was relieved after 3 perfusions of zoledronic acid and the efficiency remained at one year of follow-up.

Imaging Assessment of Periaortic Inflammation in Erdheim-Chester Disease

Reaching etiologic diagnoses for retroperitoneal fibrosis may be challenging. We report the case of a 75-year old male with history of ruptured abdominal aortic aneurysm and subsequent retroperitoneal fibrosis who developed four years later a soft tissue infiltration surrounding the ascending thoracic aorta. Thanks to his medical records and multimodality imaging assessment, the patient escaped an open-chest biopsy through histolgical reassessment of the abdominal periaortic samples that allowed the definitive diagnosis of Erdheim-Chester disease, a rare non-Langerhans histiocytosis.