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)

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.

Progressive mucinous histiocytosis treated successfully with thalidomide: a rare case report.

Hereditary progressive mucinous histiocytosis (HPMH) is an extremely rare progressive non-Langerhans cell histiocytic disorder presenting with only cutaneous manifestations. Patients typically present with multiple asymptomatic dome-shaped erythematous papules, usually involving the face and upper extremities. Twenty-six cases have been reported worldwide, with no spontaneous regression. Treatment with thalidomide stopped the progression of the disease in two cases. We report a case of progressive mucinous histiocytosis in a 31-year-old female patient with a history of tuberculosis who presented papular lesions on the face that later extended to the hands. She was treated with isoniazid for tuberculosis and isotretinoin for the skin lesions; the improvement was minimal during the next two months, with new lesions appearing on both hands. Thalidomide stopped the progression of the disease. The cause and pathogenesis of HPMH are undetermined. The pathogenesis of HPMH may be similar to that of lysosomal storage disease, considering the intra-cytoplasmic phospholipid deposition in both diseases, in addition to the likelihood of a role of macrophages in triggering the disease. In our patient, tuberculosis may have contributed.

Effective treatment of progressive nodular histiocytosis by intermediate-dose cytarabine: a case report and literature review.

BACKGROUND: Progressive nodular histiocytosis (PNH) is a rare, clinically distinct non-Langerhans cell histiocytic neoplasm affecting the skin and mucous membranes with no signs of spontaneous regression of the lesions. Patients typically have hundreds of lesions of superficial xanthomatous papules to nodules and deep larger fibrous nodules, which can be life-threatening if laryngeal mucosa was involved. So far, few cases of PNH have been reported and no effective treatment has been shown to reverse the progressive clinical course. CASE PRESENTATION: Here we describe a case of PNH presenting as diffuse, progressively enlarging papules, nodules and even leonine appearance in a young woman. The diagnosis was confirmed by histological and immunohistochemical findings. Next-generation sequencing (NGS) showed identical missense mutation in XIAP Y404C and in-frame deletion in MAPK1 A2[6>5]. Since ERK inhibitor has not been on the market yet, the patient received chemotherapy instead. Traditional chemotherapy with intermediate-dose of cytarabine (500 mg/m2 cytarabine by 3-hour infusion every 12 hours for 3 days every 5 weeks) achieved favorable therapeutic effect as confirmed by clinical symptoms and PET/CT imaging. CONCLUSIONS: PNH is a rare, proliferative disorder with disfiguring lesions and deteriorative quality of life. Mutations in MAPK1, XIAP may play crucial roles in the pathogenesis of PNH. Intermediate-dose cytarabine can be considered as a promising treatment option for PNH patients.

Haploidentical stem cell transplantation with posttransplant cyclophosphamide for refractory systemic juvenile xanthogranuloma.

Juvenile xanthogranuloma (JXG) is a generally benign, self-limited histiocytic disorder, which belongs to non-Langerhans cell histiocytoses (non-LCH). However, systemic JXG can be fatal in rare cases. We present the case of an 11-year-old female with systemic JXG, who experienced repeated vertebral compression fractures and did not fully respond to systemic chemotherapy. Based on its reported efficacy in LCH, the patient underwent human leukocyte antigen-haploidentical hematopoietic stem cell transplantation (HSCT) with posttransplant cyclophosphamide. The patient did not suffer major complications and has not experienced relapse for 13 months since HSCT. HSCT may be a potential treatment option for patients with refractory non-LCH.

Isolated Bone Marrow Non-Langerhans Cell Histiocytosis Preceding RUNX1-Mutated Acute Myeloid Leukemia: Case Report and Literature Review.

OBJECTIVES: The prevalence of concomitant myeloid neoplasms was recently reported to be unexpectedly high among adults without non-Langerhans cell histiocytosis (non-LCH); however, the coexistence of non-LCH with RUNX1 genetic aberration has not been reported previously. METHODS: Herein, we report a 23-year-old woman with severe pancytopenia diagnosed with non-LCH following presentation with pancytopenia and marrow examination showing histiocytosis positive for CD45, CD68, CD136, and lysozyme but negative for CD1a, langerin, and S100. RESULTS: Whole-exome sequencing showed RUNX1 mutation and NF1 mutation. In the ensuing 6 months, she developed hepatosplenomegaly, and repeat bone marrow evaluation was diagnostic of acute myeloid leukemia (AML). Repeat mutational analysis showed again presence of RUNX1 mutation. She underwent induction therapy but died of septic shock. CONCLUSIONS: The demonstration of RUNX1 mutation in both non-LCH and AML bone marrow specimens at differing time points is suggestive of a biologic association of both distinct disease entities.