Bone mineral density in patients with systemic mastocytosis: correlations with clinical and histopathological features.

OBJECTIVES: Systemic mastocytosis (SM) is a heterogeneous haematological entity characterised by proliferation of mast cells. Skeletal abnormalities of SM include osteolysis, osteopenia and osteoporosis but also osteosclerosis. A routinely used modality to assess bone density is dual-energy x-ray absorptiometry (DXA). The present study sought to elucidate possible associations between DXA findings with both clinical and bone marrow biopsy findings in SM. METHODS: Patient records of the local oncology and haematology department from 2007 to 2018 were screened for patients with SM. Overall, 39 patients (18 women and 21 men) with sufficient DXA images and clinical data were identified. We evaluated cKit mutation, tryptase level in serum, alkaline phosphatase, calcium level in serum, haemoglobin level, leucocytes and thrombocytes. Bone marrow biopsies were also evaluated. RESULTS: There were no significant differences between the different bone marrow patterns and in regard of cKit mutations. Significant lower bone mineral density (BMD) - T-score and Z-score values were identified for the indolent type compared to aggressive type. Correlation analysis revealed an association between BMD and tryptase level (r=0.35, p=0.049), mast cell proportion in bone marrow biopsy (r=0.45, p=0.01) and with the years since diagnosis (r=-0.42, p=0.02). Moreover, the correlations differed between the indolent and aggressive type. CONCLUSIONS: DXA findings are associated with clinical and bone marrow biopsy parameters in SM. A positive association with tryptase level and mast cell amount in bone marrow biopsies was identified. This corroborates the usefulness of DXA in SM beyond the sole assessment of osteopenia and osteoporosis.

Systemic mastocytosis revisited with an emphasis on skeletal manifestations.

Systemic mastocytosis (SM) is a rare form of mastocytosis that can affect various organ systems. Bone involvement is the most common and prominent imaging feature in patients with SM regardless of the subtype. Furthermore, bone involvement is a prognostic factor as it may entail an aggressive course of the disease. Diagnosis is established by bone marrow biopsy complemented by imaging modalities such as radiography, CT, and magnetic resonance (MR) imaging. The radiographic and CT appearances are that of sclerotic, lytic, or mixed patterns with focal or diffuse distribution, involving primarily the axial skeleton and the ends of the long bones. Bone marrow infiltration is best recognized on MR imaging. Osteoporosis is common in SM; thus, a bone mineral density measurement at lumbar spine and proximal femur by dual-energy X-ray absorptiometry should be obtained. Imaging plays a huge part in the diagnostic process; when skeletal imaging findings are carefully interpreted and correlated with clinical features, they can lead to the suspicion of SM. The primary aims of this review article were to focus on the role of imaging in detection and characterization of skeletal patterns of SM and to discuss relevant clinical features that could facilitate prompt and correct diagnosis.

Magnetic resonance imaging reveals distinct bone marrow patterns in indolent and advanced systemic mastocytosis.

Systemic mastocytosis (SM) is broadly subcategorized according to mast cell (MC) burden and organ involvement into indolent (ISM), smoldering (SSM), and advanced SM (AdvSM). However, the pattern and extent of bone involvement remains controversial. In this institutional review board (IRB)-approved study, 115 patients with different forms of SM (ISM (n = 37, 32%), SSM (n = 9, 8%), and AdvSM (n = 69, 60%)) underwent a whole-body magnetic resonance imaging including sagittal and coronal T1 and turbo inversion recovery magnitude (TIRM) sequences of the spine. The evaluation included the pattern and extent of pathologic bone marrow (BM) signals in the spine and extremities, osteolytic lesions, and vertebral fractures. A pathologic BM pattern was observed in 4/37 (11%), 8/9 (89%), and 66/69 (96%); affection of the appendicular skeleton in 3/37 (8%), 8/9 (89%), and 67/69 (97%); and vertebral fractures in 7/37 (19%), 0/9, and 13/69 (19%) patients with ISM, SSM, and AdvSM, respectively. In AdvSM, pathologic BM pattern included activated (62%), diffuse sclerotic (25%), and small-spotted BM (9%), respectively. Only activated/sclerotic BM was associated with significantly higher MC burden, organ damage, and inferior median survival (2.9 years, p = 0.04). Vertebral fractures resembled classical multi-segmental osteoporotic fractures in ISM but not in AdvSM in which they were only found in activated/sclerotic BM. Only one patient with AdvSM had a focal osteolytic lesion in the femur. Activated/sclerotic BM changes of the spine and affection of the appendicular skeleton are indicative for SSM or AdvSM. Osteolytic lesions, which are very rare, and osteoporotic fractures are ineligible for the diagnosis of AdvSM.

Systemic Mastocytosis and Essential Thrombocythemia: Case Report and Literature Overview.

Mastocytosis is a rare disease in which heightened amounts of mast cells accumulate in the skin, bone marrow, and other visceral organs. Upon activation, mast cells release a wide variety of preformed or newly synthesized mediators which can induce allergic symptoms and inflammatory reactions. Mastocytosis is diagnosed by biopsy and can be divided into cutaneous and systemic mastocytosis (SM). The first one affects the skin and is relatively benign, whilst SM, which involves bone marrow and other organs, may be aggressive and associate with both myelodisplastic and myeloproliferative diseases. Here we present a case of SM associated with essential thrombocythemia and complicated by severe osteoporosis, successfully treated with hydroxyurea, low-dose aspirin and zolendronic acid.

In utero presentation of aggressive systemic mastocytosis in a neonate.

Mastocytosis is a clinically heterogenous disease characterized by mast cell hyperplasia in skin, bone marrow and/or visceral organs. Cutaneous mastocytosis is more frequently observed in children, whereas indolent systemic mastocytosis is more commonly observed in adults. Aggressive systemic presentation, particularly of the neonate, is exceptionally rare. We present a rare case of congenital aggressive systemic mastocytosis. The patient was a 37-week-old male, born by caesarean section owing to hepatosplenomegaly and ascites diagnosed in utero, who exhibited extensive cutaneous and systemic manifestations of mastocytosis at birth. Mutation analysis of c-KIT identified D816V mutation in exon 17. Although initial bilateral bone marrow aspirates demonstrated no mast-cell infiltrates or haematological neoplasm, subsequent bone-marrow biopsies postmortem exhibited multifocal mast-cell aggregates. Clinical course was complicated by bacteraemia and cardiorespiratory failure, leading to death at 10 weeks.

Management around invasive procedures in mastocytosis: An update.

OBJECTIVE: Mastocytosis is a chronic hematologic disorder that is characterized by the accumulation of aberrant mast cells and typically involves the skin and/or bone marrow. Patients with mastocytosis are at increased risk of anaphylaxis. Based on theoretical assumptions, medical procedures requiring general anesthesia or radiocontrast media are deemed hazardous for patients with mastocytosis. The objective of this article is to provide a comprehensive overview of the actual risk of iatrogenic anaphylaxis and provide recommendations for daily practice. DATA SOURCES: Various scientific search engines were used (eg, PubMed and Medline). STUDY SELECTIONS: Because of the paucity of high-level studies on this topic, all available evidence was considered, including case reports. RESULTS: Reliable data on the incidence of iatrogenic anaphylaxis in mastocytosis are lacking. However, although the incidence as reported in (retrospective) cohort studies is higher than in the general population, it is still lower than commonly anticipated, with an incidence of 5.4% in 1 study. Adequate premedication and avoidance of certain physical stimuli can further decrease this risk by 10-fold. The role of drugs as elicitors of anaphylaxis is perhaps overestimated, and physical stimuli are at least as important in inducing release of mast cell mediators. CONCLUSION: This article provides practical recommendations for the management of invasive procedures in patients with mastocytosis based on current knowledge of this topic.

Systemic Mastocytosis, Kounis Syndrome and Coronary Intervention: Case Report and Systematic Review.

A 72-year-old male reported a long-standing history of unexplained syncope. Stress echocardiography demonstrated inducible anterior hypokinesis, and he proceeded to percutaneous coronary intervention for an 80% stenosis of the left anterior descending artery. Thirty minutes post-procedure, he experienced a pulseless electrical activity (PEA) cardiac arrest. Urgent repeat angiography demonstrated profound coronary artery spasm consistent with Kounis syndrome. Three days later, a second PEA arrest occurred. Systemic mastocytosis was ultimately diagnosed as the cause of his recurrent syncopal episodes and cardiac arrests. Our patient was discharged 56days after his cardiac arrest on appropriate immunotherapy, and has made an excellent event-free recovery. Systemic mastocytosis is the pathological accumulation of mast cells in organs, and it may cause life-threatening syncope and cardiac arrests. It is estimated to affect up to 1 in 10,000 people, however is often underdiagnosed. No previous reviews have examined cardiac manifestations of systemic mastocytosis. We undertook a structured systematic review of cardiac presentations of systemic mastocytosis in adults, screening 619 publications. Twenty-three cases met inclusion criteria; our review suggests that short-term mortality is high (22%), and patients with cardiac presentations are predominantly male (83%). Unexplained cardiac arrest (26%) may be the first presentation of this haematological disorder. From our review of the literature, we have also derived suggested management approaches for cardiologists encountering or suspecting systemic mastocytosis in a variety of clinical scenarios.

Assessment of clinical findings, tryptase levels, and bone marrow histopathology in the management of pediatric mastocytosis.

BACKGROUND: The management of children with pediatric mastocytosis poses a challenge. This is because there is limited information as to the application of clinical and laboratory findings and bone marrow histopathology as they relate to medical intervention and communication. OBJECTIVE: We sought to examine clinical aspects of pediatric mastocytosis in relationship to serum tryptase levels and bone marrow pathology to provide practical guidance for management. METHODS: Between 1986 and 2012, 105 children were evaluated at the National Institutes of Health. Organomegaly was confirmed by means of ultrasound. Baseline tryptase levels and at least 1 subsequent tryptase measurement was available in 84 and 37 of these children, respectively. Fifty-three children underwent a bone marrow examination. These data were used to examine relationships between clinical findings, tryptase levels, and marrow histopathology. RESULTS: In patients with high tryptase levels and severe mediator symptoms, all with organomegaly had systemic disease, and none without organomegaly had systemic disease. Serum tryptase levels differed significantly between patients with urticaria pigmentosa and those with diffuse cutaneous (P < .0001) and systemic mastocytosis (P < .0001) and in all 3 categories versus control subjects (P < .0001). Tryptase levels and symptoms decreased over time in most patients, and tryptase levels correlated with bone marrow mast cell burden in patients with systemic mastocytosis (P < .0001). There was a significant relationship between clinical resolution and the percentage decrease in tryptase levels (P = .0014). CONCLUSIONS: The majority of children experienced major or complete disease resolution (57%), whereas the remainder exhibited partial improvement. Organomegaly was a strong indicator of systemic disease. Serum tryptase levels furthered classification and reflected clinicopathologic findings, while sequential tryptase measurements were useful in supplementing clinical judgment as to disease course.

FDG-PET/CT findings in systemic mastocytosis: a French multicentre study.

INTRODUCTION: Mastocytosis is a clonal haematological disease characterized by uncontrolled proliferation and the activation of mast cells. The value of FDG-PET/CT (FDG-PET) in mastocytosis has yet to be determined. METHODS: We retrospectively identified patients with an established diagnosis of systemic mastocytosis (SM), according to the WHO criteria, who underwent PET using the French Reference Centre for Mastocytosis database. Semi-quantitative and visual analysis of FDG-PET was performed and compared to the clinico-biological data. RESULTS: Our cohort included 19 adult patients, median age 65 years [range 58-74], including three with smouldering SM (SSM), three with aggressive SM (ASM), 10 with an associated clonal haematological non-mast-cell lineage disease (SM-AHNMD), and three with mast cell sarcoma (MCS). FDG-PET was performed at the time of the SM diagnosis (15/19), to evaluate lymph node (LN) activity (3/19) or the efficacy of therapy (1/19). FDG uptake was observed in the bone marrow (BM) (9/19, 47%), LN (6/19, 32%), spleen (12/19, 63%), or liver (1/19, 5%). No significant FDG uptake was observed in the SSM and ASM patients. A pathological FDG uptake was observed in the BM of 6/10 patients with SM-AHNMD, appearing as diffuse and homogeneous, and in the LN of 5/10 patients. All 3 MCS patients showed intense and multifocal BM pathological uptake, mimicking metastasis. No correlation was found between the FDG-PET findings and serum tryptase levels, BM mast cell infiltration percentage, and CD30 and CD2 expression by mast cells. CONCLUSIONS: FDG uptake does not appear to be a sensitive marker of mast cell activation or proliferation because no significant FDG uptake was observed in most common forms of mastocytosis (notably purely aggressive SM). However, pathological FDG uptake was observed in the SM-AHNMD and in MCS cases, suggesting a role of FDG-PET in their early identification and as a tool of therapeutic assessment in this subgroup of patients.

High prevalence of fractures and osteoporosis in patients with indolent systemic mastocytosis.

BACKGROUND: Indolent systemic mastocytosis (ISM) is a rare disease characterized by accumulation of abnormal mast cells in various tissues, including bone marrow. Symptoms are usually related to release of mast cell mediators. The aims are to establish the prevalence of osteoporotic fractures in ISM and to investigate the association with serum tryptase and the urinary histamine metabolites, methylhistamine (MH), and methylimidazole acetic acid. METHODS: The fracture prevalence in 157 patients (65 men; 92 women), mean age 54 ± 12 years, was assessed by vertebral morphometry and data from patient records, supplemented by a questionnaire. Bone mineral density (BMD) of lumbar spine and femoral neck was measured, and tryptase and histamine metabolites were analysed. RESULTS: We registered 235 lifetime fractures in 154 patients, including 140 osteoporotic (low-energy trauma) fractures, of which 62% were vertebral, 1% hip and 36% other nonvertebral fractures. Osteoporotic fractures and osteoporosis were found in 37% and 28% of the patients, respectively. In men, the prevalence of these osteoporotic manifestations (46% <50 years; 73% ≥50 years) was much higher compared with women (18% <50 years; 58% ≥50 years). Older age, male gender, and higher urinary MH were independently related to the osteoporotic manifestations. CONCLUSIONS: This first publication about prevalence of fractures and osteoporosis in patients with ISM shows that the risk of osteoporotic fractures is high, especially in men. Higher urinary MH levels are associated with a higher risk of osteoporotic manifestations. Routine measurements of BMD and vertebral morphometry are warranted in these patients for early detection of osteoporosis.

Indolent systemic mastocytosis: is there a reliable radiographic pattern?

A 14-year-old boy undergoing treatment for nephrotic syndrome with steroids and cyclosporine presented with small sclerotic bone lesions in a routine chest radiograph. Similar lesions were found in other bones of the axial and appendicular skeleton. Despite the paucity of clinical symptoms and absence of laboratory data suggesting systemic mastocytosis, the diagnosis of an indolent form of this disorder was made based on radiographic signs and confirmed by biopsy.

Functional imaging with dual-energy computed tomography for supplementary non-invasive assessment of mast cell burden in systemic mastocytosis.

Systemic mastocytosis (SM) is characterized by multifocal accumulation of neoplastic mast cells (MCs), predominately affecting the bone marrow (BM). Imaging with computed tomography (CT) is used for assessment of bone mineral density and structure. However, the value of functional imaging with dual-energy CT (DECT) and the assessment of virtual-non-calcium attenuation values (VNCa-AV) for visualization of BM disease burden in SM has not yet been assessed. DECT of the axial skeleton was performed in 18 patients with SM (indolent SM [ISM], n = 6; smoldering SM [SSM]/advanced SM [AdvSM], n = 12) and 18 control subjects. VNCa-AV were obtained in 5 representative vertebraes per patient and correlated with laboratory, morphologic and molecular parameters. VNCa-AV strongly correlated with quantitative BM MC infiltration (r = 0.7, R2 = 0.49, P = 0.001) and serum tryptase levels (r = 0.7, R2 = 0.54, P < 0.001). Mean VNCa-AV were significantly higher in SSM/AdvSM as compared to ISM (- 9HU vs. - 54HU, P < 0.005) and controls (- 38HU, P < 0.005). Nine of 10 (90%) patients with a VNCa-AV > - 30HU and 7/7 (100%) patients with a VNCa-AV > - 10HU had SSM or AdVSM. BM VNCa-AV provide information about the MC burden of SM patients and correlate with SM subtypes. DECT may therefore serve as a supplementary tool for SM diagnosis, subclassification and monitoring in a one-stop-shop session.

Aggressive systemic mastocytosis with diffuse bone marrow 18F-FDG uptake.

Mastocytosis is a clonal hematopoietic disorder characterized by proliferation of abnormal mast cells in various organs including the skin, digestive system, lymph nodes, and bone marrow. We report on a 75-year-old woman presenting with abdominal pain, vomiting, diarrhoea, myalgia, and weight loss. Abdominal CT showed hepatosplenomegaly with heterogeneous splenic parenchyma, lymphadenopathy, and osteopenia with areas of osteosclerosis but no primary tumour. An 18F-FDG PET/CT revealed an overall low metabolic activity of the lesions with a diffuse bone marrow involvement raising suspicion of a haematological neoplasm. Subsequently, bone marrow and peripheral blood examinations confirmed the diagnosis of aggressive systemic mastocytosis.

CXCR4 Expression Demonstrated by 68Ga-Pentixafor PET/CT Imaging in a Case of Systemic Mastocytosis Mimicking Lymphoma.

ABSTRACT: 68Ga-Pentixafor is a novel radiotracer for imaging chemokine receptor subtype 4 (CXCR4) receptors, which are expressed exceptionally high in several hematologic malignancies, including various types of lymphoma. Herein we report a case of a 64-year-old man patient with suspected hematologic malignancy who underwent 18F-FDG and 68Ga-pentixafor PET/CT. Both scans demonstrated diffusely increased activity related to bone marrow involvement. 68Ga-Pentixafor PET/CT demonstrated CXCR4-expressing intra-abdominal lymph nodes that were not detected by 18F-FDG PET/CT. The patient was highly suspicious of lymphoma; however, histopathological examination of the bone marrow revealed systemic mastocytosis with associated myelofibrosis.

An increased bone mineral density is an adverse prognostic factor in patients with systemic mastocytosis.

PURPOSE: Systemic mastocytosis (SM) is characterized by the expansion of clonal mast cells that infiltrate various organ systems. The extent of organ infiltration and subsequent organ damage distinguishes between indolent SM (ISM) defined by a nearly normal life expectancy and advanced SM (AdvSM) defined by poor prognosis. In ISM, measurement of the bone mineral density (BMD) frequently reveals osteoporosis. In contrast, the clinical implication of an increased BMD and osteosclerosis remains unclear. METHODS: BMD was evaluated in 61 patients with mastocytosis (ISM, n = 29, 48%; AdvSM, n = 32, 52%). We correlated the prevalence of osteoporosis, increased BMD and osteosclerosis with clinical parameters, disease variant and prognosis. RESULTS: Osteoporosis was detected in 11/29 (38%) patients with ISM but only in 2/32 (6%) patients with AdvSM (p = 0.004). An increased BMD was detected in 1/29 (3%) patients with ISM and 24/32 (75%) patients with AdvSM (p < 0.001) while osteosclerosis was only detected in AdvSM patients (16/32, 50%). AdvSM patients with increased BMD had higher levels of bone marrow mast cell infiltration, higher serum tryptase and alkaline phosphatase levels compared to ISM as well as higher number of high-molecular risk mutations (p < 0.05). In addition, we found that the prognosis of AdvSM patients with increased BMD is inferior compared to those without increased BMD (median overall survival 3.6 years versus not reached, p = 0.031). CONCLUSIONS: Osteoporosis is a common feature in ISM but not in AdvSM. An increased BMD is frequently present in AdvSM but not in ISM and is associated with more advanced disease and inferior outcome.

Routine abdominal ultrasonography has limited value in the care for patients with indolent systemic mastocytosis.

OBJECTIVES: Systemic mastocytosis (SM) is a myeloproliferative disease characterized by the accumulation of aberrant mast cells. Since advanced subtypes of SM can lead to organ dysfunction and shortened survival, timely recognition of progressive disease is important for the adequate treatment of SM patients. METHODS: Here, we report the results of our cohort study on the value of routine abdominal ultrasonography for the detection of progression of indolent systemic mastocytosis (ISM). RESULTS: We included 88 patients with ISM, of whom 9 developed new hepatosplenomegaly during follow-up. In this group, the median serum tryptase level increased by 11.60 µg/l, compared with a decrease of -0.20 µg/l in the 79 patients with unchanged ultrasonography results (p = 0.016). A change in liver and/or spleen size never led to a change in clinical classification, nor management. DISCUSSION: Based on the finding that a change in ultrasonography findings did not correlate to disease progression in general, it appears that isolated hepatosplenomegaly does not have prognostic implications in patients with ISM. CONCLUSIONS: Routine abdominal ultrasonography is redundant in the follow-up of patients with ISM. A combination of physical examination with serum tryptase levels can be used to screen for hepatosplenomegaly.

Systemic mastocytosis: A rare cause of non-cirrhotic portal hypertension.

Mastocytosis is a clonal neoplastic disorder of the mast cells (MC) that can be limited to the skin (cutaneous mastocytosis) or involve one or more extracutaneous organs (systemic mastocytosis). The clinical manifestations of mastocytosis are heterogeneous ranging from indolent disease with a long-term survival to a highly aggressive neoplasm with survival of about 6 mo. Although liver involvement in aggressive systemic mastocytosis (ASM) is relatively common, the development of portal hypertension with or without cirrhosis is rare. We report a case of ASM without skin involvement in a 72-year-old caucasian male who presented with non-cirrhotic portal hypertension based on clinical, analytical, imagiological and endoscopic findings. Given the hematological picture, the correct diagnosis was established based on ancillary tests for MC using bone marrow aspirates and biopsy. Extensive involvement of the liver and gastrointestinal tract was histologically documented. The disease progressed rapidly and severe pancytopenia and recurrent upper gastrointestinal bleeding became the dominant problem. This case illustrates the challenge in establishing a diagnosis of ASM especially when the clinical picture is atypical and without skin involvement. Gastroenterologists should consider infiltrative disease, particularly systemic mastocytosis, as a differential diagnosis in a clinical case of portal hypertension of unknown etiology.