First Transcriptome Analysis of Hepatoblastoma in Brazil: Unraveling the Pivotal Role of Noncoding RNAs and Metabolic Pathways.

Hepatoblastoma stands as the most prevalent liver cancer in the pediatric population. Characterized by a low mutational burden, chromosomal and epigenetic alterations are key drivers of its tumorigenesis. Transcriptome analysis is a powerful tool for unraveling the molecular intricacies of hepatoblastoma, shedding light on the effects of genetic and epigenetic changes on gene expression. In this study conducted in Brazilian patients, an in-depth whole transcriptome analysis was performed on 14 primary hepatoblastomas, compared to control liver tissues. The analysis unveiled 1,492 differentially expressed genes (1,031 upregulated and 461 downregulated), including 920 protein-coding genes (62%). Upregulated biological processes were linked to cell differentiation, signaling, morphogenesis, and development, involving known hepatoblastoma-associated genes (DLK1, MEG3, HDAC2, TET1, HMGA2, DKK1, DKK4), alongside with novel findings (GYNG4, CDH3, and TNFRSF19). Downregulated processes predominantly centered around oxidation and metabolism, affecting amines, nicotinamides, and lipids, featuring novel discoveries like the repression of SYT7, TTC36, THRSP, CCND1, GCK and CAMK2B. Two genes, which displayed a concordant pattern of DNA methylation alteration in their promoter regions and dysregulation in the transcriptome, were further validated by RT-qPCR: the upregulated TNFRSF19, a key gene in the embryonic development, and the repressed THRSP, connected to lipid metabolism. Furthermore, based on protein-protein interaction analysis, we identified genes holding central positions in the network, such as HDAC2, CCND1, GCK, and CAMK2B, among others, that emerged as prime candidates warranting functional validation in future studies. Notably, a significant dysregulation of non-coding RNAs (ncRNAs), predominantly upregulated transcripts, was observed, with 42% of the top 50 highly expressed genes being ncRNAs. An integrative miRNA-mRNA analysis revealed crucial biological processes associated with metabolism, oxidation reactions of lipids and carbohydrates, and methylation-dependent chromatin silencing. In particular, four upregulated miRNAs (miR-186, miR-214, miR-377, and miR-494) played a pivotal role in the network, potentially targeting multiple protein-coding transcripts, including CCND1 and CAMK2B. In summary, our transcriptome analysis highlighted disrupted embryonic development as well as metabolic pathways, particularly those involving lipids, emphasizing the emerging role of ncRNAs as epigenetic regulators in hepatoblastomas. These findings provide insights into the complexity of the hepatoblastoma transcriptome and identify potential targets for future therapeutic interventions.

Influence of different asparaginase formulations in the prognosis of children with acute lymphocytic leukaemia in Brazil: a multicentre, retrospective controlled study.

Our group recently showed that the (ASNase) formulation available in Brazil from 2017 to 2018 when used at the same dose and frequency as the formulation provided previously did not reach the activity considered therapeutic. Based on these, our goal was to assess the impact of these facts on the prognosis of children with ALL at different oncology centers. A multicentre retrospective observational study followed by a prospective follow-up. Patients aged >1 and <18 years in first-line treatment followed up at 10 referral centres, between 2014 and 2018 who received the formulation Leuginase® were identified (Group B). For each patient, the centre registered 2 patients who received ASNase in the presentation of Aginasa® exclusively (Group A). Data collection was registered using (Redcap® ). A total of 419 patients were included; 282 in Group A and 137 in B. Group A had a 3-year OS and EFS of 91·8% and 84·8% respectively, while Group B had a 3-year OS of 83·8% (P = 0·003) and EFS of 76·1% (P = 0·008). There was an impact on 3-year OS and EFS of children who received a formulation. This result highlights the importance of evaluating ASNase and monitoring its activity.

Hepatoblastomas exhibit marked NNMT downregulation driven by promoter DNA hypermethylation.

Hepatoblastomas exhibit the lowest mutational burden among pediatric tumors. We previously showed that epigenetic disruption is crucial for hepatoblastoma carcinogenesis. Our data revealed hypermethylation of nicotinamide N-methyltransferase, a highly expressed gene in adipocytes and hepatocytes. The expression pattern and the role of nicotinamide N-methyltransferase in pediatric liver tumors have not yet been explored, and this study aimed to evaluate the effect of nicotinamide N-methyltransferase hypermethylation in hepatoblastomas. We evaluated 45 hepatoblastomas and 26 non-tumoral liver samples. We examined in hepatoblastomas if the observed nicotinamide N-methyltransferase promoter hypermethylation could lead to dysregulation of expression by measuring mRNA and protein levels by real-time quantitative polymerase chain reaction, immunohistochemistry, and Western blot assays. The potential impact of nicotinamide N-methyltransferase changes was evaluated on the metabolic profile by high-resolution magic angle spinning nuclear magnetic resonance spectroscopy. Significant nicotinamide N-methyltransferase downregulation was revealed in hepatoblastomas, with two orders of magnitude lower nicotinamide N-methyltransferase expression in tumor samples and hepatoblastoma cell lines than in hepatocellular carcinoma cell lines. A specific TSS1500 CpG site (cg02094283) of nicotinamide N-methyltransferase was hypermethylated in tumors, with an inverse correlation between its methylation level and nicotinamide N-methyltransferase expression. A marked global reduction of the nicotinamide N-methyltransferase protein was validated in tumors, with strong correlation between gene and protein expression. Of note, higher nicotinamide N-methyltransferase expression was statistically associated with late hepatoblastoma diagnosis, a known clinical variable of worse prognosis. In addition, untargeted metabolomics analysis detected aberrant lipid metabolism in hepatoblastomas. Data presented here showed the first evidence that nicotinamide N-methyltransferase reduction occurs in hepatoblastomas, providing further support that the nicotinamide N-methyltransferase downregulation is a wide phenomenon in liver cancer. Furthermore, this study unraveled the role of DNA methylation in the regulation of nicotinamide N-methyltransferase expression in hepatoblastomas, in addition to evaluate the potential effect of nicotinamide N-methyltransferase reduction in the metabolism of these tumors. These preliminary findings also suggested that nicotinamide N-methyltransferase level may be a potential prognostic biomarker for hepatoblastoma.

Malignant paraganglioma in children treated with embolization prior to surgical excision.

BACKGROUND: Paragangliomas (PGL) are rare tumors derived from neural crest cells, whose origins may vary along the chain of the sympathetic nervous system. Such tumors are often characterized by secretion of catecholamines, but sometimes they are biochemically inactive, which makes diagnosis often challenging. Malignant paraganglioma is defined by the presence of this tumor at sites where chromaffin cells are usually not found or by local invasion of the primary tumor. Recurrence, either regional or metastatic, usually occurs within 5 years of the initial complete resection but long-term recurrence is also described. Malignancy is often linked to a SDHB mutation. Preoperative embolization has been applied in the surgical management of PGLs with the objective to decrease intra-operative blood loss and surgery length without complications. CASE PRESENTATION: We report two cases of patients with abdominal or pelvic malignant PGLs who have been treated surgically at our center after preoperative embolization. Surgery was a very challenging procedure with multiple surgical teams involved and embolization did not prevent major blood loss and intraoperative complications. Patients required adjuvant treatment with either chemotherapy or radiotherapy. CONCLUSIONS: Many studies in the adult population have established recommendations for the diagnosis and therapeutic management of PGL, but few studies concern the pediatric population. Because malignant PGL is more important in the pediatric population, screening and early diagnosis of PGL is advisable in children with genetic predisposing. Surgical resection is the mainstay of treatment, but a multimodal approach is often required due to the complexity of cases.  The role of preoperative embolization is not established and in our experience it has provided little benefit and major complications.

Beyond Clinical Trials: Understanding Neurotrophic Tropomyosin Receptor Kinase Inhibitor Challenges and Efficacy in Real-World Pediatric Oncology.

PURPOSE: Our study aimed to explore real-world treatment scenarios for children and adolescents with neurotrophic tropomyosin receptor kinase (NTRK)-fused tumors, emphasizing access, responses, side effects, and outcomes. PATIENTS AND METHODS: Pooled clinical data from 17 pediatric cases (11 soft-tissue sarcomas, five brain tumors, and one neuroblastoma) treated with larotrectinib and radiologic images for 14 patients were centrally reviewed. Testing for gene fusions was prompted by poor response to treatment, tumor progression, or aggressiveness. RESULTS: Six different NTRK fusion subtypes were detected, and various payment sources for testing and medication were reported. Radiologic review revealed objective tumor responses (OR) in 11 of 14 patients: Complete responses: two; partial responses: nine; and stable disease: three cases. Grades 1 or 2 Common Terminology Criteria for Adverse Events adverse effects were reported in five patients. Regarding the entire cohort's clinical information, 15 of 17 patients remain alive (median observation time: 25 months): four with no evidence of disease and 11 alive with disease (10 without progression). One patient developed resistance to the NTRK inhibitor and died from disease progression while another patient died due to an unrelated cause. CONCLUSION: This real-world study confirms favorable agnostic tumor OR rates to larotrectinib in children with NTRK-fused tumors. Better coordination to facilitate access to medication remains a challenge, particularly in middle-income countries like Brazil.

Wilms tumor in children: A multivariate analysis of prognostic factors, with emphasis on inferior vena cava/right atrium extension. Results from a single-center study.

BACKGROUND: To identify prognostic factors for overall survival through the analysis of 132 patients with Wilms tumor followed at a single center, with emphasis on the inferior vena cava/right atrium extension. METHODS: Retrospective analysis of overall survival using logistic regression models and including age, sex, clinical features, associated syndromes, comorbidities, tumor size before chemotherapy, stage, presence of metastatic disease and its site, invasion of adjacent structures, inferior vena cava/right atrium extension, laterality, tumor histology, chemotherapy protocol, and radiotherapy as potential risk factors. RESULTS: From January 2000 through November 2021, 132 patients met the inclusion criteria, 64 females and 68 males; 15 (11.4%) patients presented with tumoral extension to inferior vena cava/right atrium and 44 had metastatic disease (33.3%). Based on logistic regression, the factors correlating to a fatal outcome were male sex (p = 0.046), high risk histology (p = 0.036), and the presence of metastatic disease (p = 0.003). None of the patients presenting inferior vena cava/right atrium extension died (p = 0.992). In a specific analysis of metastatic sites, hepatic metastasis alone showed correlation with a fatal outcome (p = 0.001). CONCLUSION: These results underline the importance of identifying and treating metastatic disease and high-risk tumors. The female gender as a potential driver for a less aggressive disease is a new finding that deserves further investigation. The accurate identification of inferior vena cava/right atrium extension, subsequent preoperative chemotherapy, and resection with a skilled team promoted survival rates of all patients. LEVEL OF EVIDENCE: II.

Acute promyelocytic leukemia in childhood and adolescence: treatment results of a modified AIDA protocol at a Brazilian center.

INTRODUCTION: Acute promyelocytic leukemia currently presents an excellent chance of cure with protocols based on all-trans-retinoic acid (ATRA) and anthracycline or only differentiation agents. However, high early mortality rates continue to be reported METHODS: Between 2000 and 2018, patients were enrolled and retrospectively analyzed by medical records. A modified AIDA protocol, with a 1-year shortening of the treatment duration, reduction in the number of drugs and a strategy to reduce early mortality by the postponement of the initiation of anthracyclines were employed. Overall and event-free survival rates and toxicity were analyzed RESULTS: Thirty-two patients were enrolled, of whom 56% were female, with a median age of 12 years and 34% belonged to the high-risk group. Two patients had the hypogranular variant and three had another cytogenetic alteration, in addition to the t(15;17). The median start of the first anthracycline dose was 7 days. There were two early deaths (6%) due to central nervous system (CNS) bleeding. All patients achieved molecular remission after the consolidation phase. Two children relapsed and were rescued by arsenic trioxide and hematopoietic stem cell transplantation. The presence of disseminated intravascular coagulation (DIC) at diagnosis (p = 0.03) was the only factor with survival impact. The five-year event-free survival (EFS) was 84% and 5-year overall survival (OS) was 90% CONCLUSION: The survival results were comparable to those found in the AIDA protocol, with a low rate of early mortality in relation to the Brazilian reality.

Major discrepancy between clinical diagnosis of death and anatomopathological findings in adolescents with chronic diseases during 18-years.

OBJECTIVES: To evaluate the inconsistency between clinical diagnosis of death and autopsy findings in adolescents with chronic diseases. METHODS: A cross-sectional study including a sample of adolescents' autopsies who died in a pediatric and adolescent tertiary hospital over 18 consecutive years. During this period, there were n = 2912 deaths, and n = 581/2912(20%) occurred in adolescents. Of these, n = 85/581(15%) underwent autopsies and were analyzed. Further results were divided into two groups: Goldman classes I or II (high disagreement between main clinical diagnosis of death and anatomopathological findings, n = 26) and Goldman classes III, IV or V (low or no disagreement between these two parameters, n = 59). RESULTS: Median age at death (13.5 [10‒19] vs. 13 [10‒19] years, p = 0.495) and disease duration (22 [0‒164] vs. 20 [0‒200] months, p = 0.931), and frequencies for males (58% vs. 44%, p = 0.247) were similar between class I/II vs. class III/IV/V. The frequency of pneumonia (73% vs. 48%, p = 0.029), pulmonary abscess (12% vs. 0%, p = 0.026), as well as isolation of yeast (27% vs. 5%, p = 0.008), and virus (15% vs. 2%, p = 0.029) identified in the autopsy, were significantly higher in adolescents with Goldman class I/II compared to those with Goldman class III/IV/V. In contrast, cerebral edema was significantly lower in adolescents of the first group (4% vs. 25%, p = 0.018). CONCLUSION: This study showed that 30% of the adolescents with chronic diseases had major discrepancies between clinical diagnosis of death and autopsy findings. Pneumonia, pulmonary abscess, as well as isolation of yeast and virus were more frequently identified at autopsy findings in the groups with major discrepancies.

Unraveling the Genetic Architecture of Hepatoblastoma Risk: Birth Defects and Increased Burden of Germline Damaging Variants in Gastrointestinal/Renal Cancer Predisposition and DNA Repair Genes.

The ultrarare hepatoblastoma (HB) is the most common pediatric liver cancer. HB risk is related to a few rare syndromes, and the molecular bases remain elusive for most cases. We investigated the burden of rare damaging germline variants in 30 Brazilian patients with HB and the presence of additional clinical signs. A high frequency of prematurity (20%) and birth defects (37%), especially craniofacial (17%, including craniosynostosis) and kidney (7%) anomalies, was observed. Putative pathogenic or likely pathogenic monoallelic germline variants mapped to 10 cancer predisposition genes (CPGs: APC, CHEK2, DROSHA, ERCC5, FAH, MSH2, MUTYH, RPS19, TGFBR2 and VHL) were detected in 33% of the patients, only 40% of them with a family history of cancer. These findings showed a predominance of CPGs with a known link to gastrointestinal/colorectal and renal cancer risk. A remarkable feature was an enrichment of rare damaging variants affecting different classes of DNA repair genes, particularly those known as Fanconi anemia genes. Moreover, several potentially deleterious variants mapped to genes impacting liver functions were disclosed. To our knowledge, this is the largest assessment of rare germline variants in HB patients to date, contributing to elucidate the genetic architecture of HB risk.

Technical performance of a lateral flow immunoassay for detection of anti-SARS-CoV-2 IgG in the outpatient follow-up of non-severe cases and at different times after vaccination: comparison with enzyme and chemiluminescent immunoassays.

This study assessed the technical performance of a rapid lateral flow immunochromatographic assay (LFIA) for the detection of anti-SARS-CoV-2 IgG and compared LFIA results with chemiluminescent immunoassay (CLIA) results and an in-house enzyme immunoassay (EIA). To this end, a total of 216 whole blood or serum samples from three groups were analyzed: the first group was composed of 68 true negative cases corresponding to blood bank donors, healthy young volunteers, and eight pediatric patients diagnosed with other coronavirus infections. The serum samples from these participants were obtained and stored in a pre-COVID-19 period, thus they were not expected to have COVID-19. In the second group of true positive cases, we chose to replace natural cases of COVID-19 by 96 participants who were expected to have produced anti-SARS-CoV-2 IgG antibodies 30-60 days after the vaccine booster dose. The serum samples were collected on the same day that LFIA were tested either by EIA or CLIA. The third study group was composed of 52 participants (12 adults and 40 children) who did or did not have anti-SARS-CoV-2 IgG antibodies due to specific clinical scenarios. The 12 adults had been vaccinated more than seven months before LFIA testing, and the 40 children had non-severe COVID-19 diagnosed using RT-PCR during the acute phase of infection. They were referred for outpatient follow-up and during this period the serum samples were collected and tested by CLIA and LFIA. All tests were performed by the same healthcare operator and there was no variation of LFIA results when tests were performed on finger prick whole blood or serum samples, so that results were grouped for analysis. LFIA's sensitivity in detecting anti-SARS-CoV-2 IgG antibodies was 90%, specificity 97.6%, efficiency 93%, PPV 98.3%, NPV 86.6%, and likelihood ratio for a positive or a negative result were 37.5 and 0.01 respectively. There was a good agreement (Kappa index of 0.677) between LFIA results and serological (EIA or CLIA) results. In conclusion, LFIA analyzed in this study showed a good technical performance and agreement with reference serological assays (EIA or CLIA), therefore it can be recommended for use in the outpatient follow-up of non-severe cases of COVID-19 and to assess anti-SARS-CoV-2 IgG antibody production induced by vaccination and the antibodies decrease over time. However, LFIAs should be confirmed by using reference serological assays whenever possible.

P-glycoprotein expression, tumor weight, age, and relapse in patients with stage I and II favorable-histology Wilms' tumor.

Fifteen percent of patients with Wilms' tumor (WT) experience relapse. It has been suggested that weight and age may affect the chances of relapse. Few studies have investigated the role, if any, between P-glycoprotein (P-gp) and relapse. The authors assessed the prognostic value of tumor weight and age at diagnosis and asked whether some other potential biological markers, specifically P-gp protein expression, had a prognostic value in favorable-histology WT. No association between age and relapse could be found. Patients with tumor weight ≥550 g were 6 times more likely to relapse, whereas P-gp expression was positive in 18/40 (45%) of the patients, of which 10/12 (83.3%) relapsed and 8/28 (28.6%) did not. Further studies are necessary to elucidate whether or not P-gp is related to relapse in patients with histologically favorable Wilms' tumor. If confirmed, the protein may be used in the future as a target for new drugs and treatments for this group of patients.

Prevalence and outcomes of thrombotic and hemorrhagic complications in pediatric acute promyelocytic leukemia in a tertiary Brazilian center.

INTRODUCTION: Little attention is given to thrombosis associated with pediatric acute promyelocytic leukemia (APL). This study describes the thrombotic and hemorrhagic manifestations of APL in pediatric patients and evaluates their hemostasis, based on coagulation tests. METHODS: Inclusion criteria were age 0-18 years and APL diagnosis between April 2005 and November 2017. Patients who had received blood transfusion prior to coagulation tests were excluded. Baseline coagulation tests, hematologic counts, and hemorrhagic/thrombotic manifestations were evaluated. RESULTS: Median age was 10.7 years (1-15 years). The initial coagulation tests revealed a median Hgb of 8.3 g/dL (4.7-12.9 g/dL), median leucocyte count of 10.9 × 109/L (1.1-95.8 × 109/L), median platelet count of 31.8 × 109/L (2.0-109.0 × 109/L), median activated partial thromboplastin time (aPTT) of 31.7 s (23.0-50.4 s), median aPTT ratio of 1.0 (0.78-1.6), median thromboplastin time (PT) of 17.5 s (13.8-27.7 s), median PT activity of 62% (25-95 %), and median fibrinogen of 157.7 mg/dL (60.0-281.0 mg/dL). Three patients (13%) had thrombosis. At diagnosis, 21 patients (91.3%) had bruising, one patient (4.3%) had splenic vein and artery thrombosis and one patient (4.3%) presented without thrombohemorrhagic manifestations. During treatment, two patients (8.6%) had thrombosis. CONCLUSION: Knowledge of thrombosis in pediatric APL is important to determine its risk factors and the best way to treat and prevent this complication.

Breakthrough Candidemia in Pediatric Patients With Cancer From a Brazilian Center.

We analyzed 19 cases of breakthrough candidemia from a referral pediatric cancer center in Brazil. All patients had neutropenia and were under antifungal prophylactic regimens, mostly micafungin (68%). Most of the patients were treated with amphotericin B formulations and 30-day mortality was 21%. Candida parapsilosis was the main etiologic agent (63%), and horizontal transmission was not evidenced by microsatellite analysis.

Copy Number Alterations in Hepatoblastoma: Literature Review and a Brazilian Cohort Analysis Highlight New Biological Pathways.

Hepatoblastoma (HB) is a rare embryonal tumor, although it is the most common pediatric liver cancer. The aim of this study was to provide an accurate cytogenomic profile of this type of cancer, for which information in cancer databases is lacking. We performed an extensive literature review of cytogenetic studies on HBs disclosing that the most frequent copy number alterations (CNAs) are gains of 1q, 2/2q, 8/8q, and 20; and losses at 1p and 4q. Furthermore, the CNA profile of a Brazilian cohort of 26 HBs was obtained by array-CGH; the most recurrent CNAs were the same as shown in the literature review. Importantly, HBs from female patients, high-risk stratification tumors, tumors who developed in older patients (> 3 years at diagnosis) or from patients with metastasis and/or deceased carried a higher diversity of chromosomal alterations, specifically chromosomal losses at 1p, 4, 11q and 18q. In addition, we distinguished three major CNA profiles: no detectable CNA, few CNAs and tumors with complex genomes. Tumors with simpler genomes exhibited a significant association with the epithelial fetal subtype of HBs; in contrast, the complex genome group included three cases with epithelial embryonal histology, as well as the only HB with HCC features. A significant association of complex HB genomes was observed with older patients who developed high-risk tumors, metastasis, and deceased. Moreover, two patients with HBs exhibiting complex genomes were born with congenital anomalies. Together, these findings suggest that a high load of CNAs, mainly chromosomal losses, particularly losses at 1p and 18, increases the tendency to HB aggressiveness. Additionally, we identified six hot-spot chromosome regions most frequently affected in the entire group: 1q31.3q42.3, 2q23.3q37.3, and 20p13p11.1 gains, besides a 5,3 Mb amplification at 2q24.2q24.3, and losses at 1p36.33p35.1, 4p14 and 4q21.22q25. An in-silico analysis using the genes mapped to these six regions revealed several enriched biological pathways such as ERK Signaling, MicroRNAs in Cancer, and the PI3K-Akt Signaling, in addition to the WNT Signaling pathway; further investigation is required to evaluate if disturbances of these pathways can contribute to HB tumorigenesis. The analyzed gene set was found to be associated with neoplasms, abnormalities of metabolism/homeostasis and liver morphology, as well as abnormal embryonic development and cytokine secretion. In conclusion, we have provided a comprehensive characterization of the spectrum of chromosomal alterations reported in HBs and identified specific genomic regions recurrently altered in a Brazilian HB group, pointing to new biological pathways, and relevant clinical associations.

Involvement of the central nervous system in neuroblastomas: A potential direct pathway.

Although frequently disseminated to other anatomical sites, neuroblastoma (NB) is rarely reported as involving the central nervous system (CNS), which may reflect insufficient research in poorly controlled systemic disease. Here we demonstrate the involvement of the CNS in patients with NB over 18 months of age at diagnosis of extensive systemic disease. Meningeal metastases were observed even in the presence of complete systemic control. Although no improvement in patient's survival was observed, radiotherapy was effective in preventing CNS recurrence after observation of actual or previous dural disease. In conclusion, this study uncovered the uncommon pathologic involvement of the CNS in children with advanced NB and underscores the meningeal surface as a potential pathway for this to occur.

[Musculoskeletal involvement as a first manifestation of neoplasm disease]. / Comprometimento musculoesquelético como primeira manifestação de neoplasias.

OBJECTIVE: To describe the clinical and laboratory findings that contributed for the diagnosis of neoplasia in patients with musculoskeletal symptoms at presentation. METHODS: Retrospective analysis of medical records from patients with final diagnosis of neoplasia attended at the "Unidade de Reumatologia do Instituto da Criança - FMUSP" between January 1983 and December 2006. Data on musculoskeletal complaints, clinical examination, laboratory tests, radiological studies and diagnostic procedures were obtained. RESULTS: From 4876 patients, 25 (0.5%) children were studied (52% with acute lymphoid leukemia and 24% with neuroblastoma). Twenty children (80%) presented arthritis and/or arthralgia at onset of the disease. All patients presented systemic symptoms, such as fever (22 cases - 88%). The initial blood cell count was abnormal in 16 patients (64%), showing anemia and thrombocytopenia (12 and 5 cases, respectively). Blast cells were present in only two patients and eleven patients developed blood cell count abnormalities during follow-up. X-ray studies showed abnormalities in 11/14 patients, ultrasound in 12/18, scintigraphy in 5/5, CT in 7/9 and MRI in 3/3. Bone marrow smear was abnormal in 18/22 patients, but in three of them the abnormalities were not detected by the first test. CONCLUSION: Musculoskeletal symptoms are common at the onset of neoplasia, especially for acute lymphoid leukemia, and this possibility should be considered in the differential diagnosis of rheumatic diseases. Laboratory tests may be normal at the onset of the disease, therefore serial exams should be performed. For a correct diagnosis. radiological studies and bone marrow aspiration have proven to be essential.