Whole-Body Low-Dose Multidetector-Row CT in Multiple Myeloma: Guidance in Performing, Observing, and Interpreting the Imaging Findings

Multiple myeloma is a hematological malignancy of plasma cells usually detected due to various bone abnormalities on imaging and rare extraosseous abnormalities. The traditional approach for disease detection was based on plain radiographs, showing typical lytic lesions. Still, this technique has many limitations in terms of diagnosis and assessment of response to treatment. The new approach to assess osteolytic lesions in patients newly diagnosed with multiple myeloma is based on total-body low-dose CT. The purpose of this paper is to suggest a guide for radiologists in performing and evaluating a total-body low-dose CT in patients with multiple myeloma, both newly-diagnosed and in follow-up (pre and post treatment).

Differential Diagnosis of Cysts and Granulomas Supported by Texture Analysis of Intraoral Radiographs

The aim of this study was to evaluate whether textural analysis could differentiate between the two common types of lytic lesions imaged with use of radiography. Sixty-two patients were enrolled in the study with intraoral radiograph images and a histological reference study. Full textural analysis was performed using MaZda software. For over 10,000 features, logistic regression models were applied. Fragments containing lesion edges were characterized by significant correlation of structural information. Although the input images were stored using lossy compression and their scale was not preserved, the obtained results confirmed the possibility of distinguishing between cysts and granulomas with use of textural analysis of intraoral radiographs. It was shown that the important information distinguishing the aforementioned types of lesions is located at the edges and not within the lesion.

Epidemiology Unknown: Developing an Approach to Identify Potential Smoldering Multiple Myeloma Cases

Background Smoldering Multiple Myeloma (SMM) is an asymptomatic clonal plasma cell disorder that identifies patients at risk for progression to Multiple Myeloma (MM). The standard of care for SMM has traditionally been observation, but some cancer centers are now treating high-risk SMM before progression to MM. The diagnostic criteria for SMM have also changed in recent years, and current estimates of SMM are derived from large MM databases and observations from tertiary centers. The goal of this study was to develop an approach for identifying SMM cases in a large integrated healthcare delivery system to better characterize the epidemiology of SMM in community-based populations. Methods This retrospective, observational study was conducted in Kaiser Permanente Northern California (KPNC) using KPNC SEER-based Cancer Registry data and information from the electronic health record (EHR). Potential SMM cases from 1/1/2010 to 12/31/2018 were identified using three approaches: Group 1 - identified via the KPNC Cancer Registry based on indicators of 'asymptomatic myeloma', 'evolving myeloma', and 'smoldering myeloma'; Group 2 - identified via the KPNC Cancer Registry as MM cases who had a physician visit note containing the word 'smoldering' but did not begin treatment within 1 year of diagnosis; Group 3 - identified via the KPNC Cancer Registry as MM cases who had a physician visit note containing the word 'smoldering' but did begin treatment within 1 year of diagnosis. Chart review was performed for these potential SMM cases (Groups 1-3) to document initial bone marrow biopsy results (bone marrow plasma cell percentage, BMPC) and skeletal findings (presence or absence of lytic bone lesions) around the time of biopsy. When BMPC was reported as a range, the highest value was captured. Patient demographics (age, sex and race/ethnicity) were obtained from the EHR. Bivariate analyses were performed using the chi-squared test and the Wilcoxon-Mann-Whitney nonparametric test. For binomial comparisons by mode of potential SMM case identification, Groups 1 and 2 were combined and compared to Group 3. Results A total of 471 potential SMM cases were identified, including 178 (37.8%) via Group 1, 35 (7.4%) via Group 2, and 258 (54.8%) via Group 3 (Figure). The median age was 71 years (interquartile range, IQR 62-78) and 40.0% were female. The racial/ethnic distribution included 57.1% White, 17.6% Black, 10.8% Hispanic, 13.6% Asian, and 0.9% other/unknown race. There were no significant differences across groups (Group 1+2 vs Group 3) with respect to age (p=0.07), sex (p=0.85), or race/ethnicity (p=0.81). There were 442 (93.8%) who underwent bone marrow biopsy. Among those with BMPC data, the median BMPC for Group 1 was 20.0% (IQR 10.0%-28.0%); for Group 2 was 25.0% (IQR 12.5%-50.0%), for Group 3 was 28.0% (IQR 15.0%-50.0%) (p<0.001 comparing Groups 1+2, combined median 20.0%, IQR 10.0%-30.0%, vs Group 3, 28.0%, IQR 15.0%-50.0%). The proportion with BMPC ≥60% was 4%, 13%, and 22% for Groups 1, 2, and 3, respectively (Figure). There were 413 (87.7%) who had skeletal imaging (n=405, 86.0% with available results) within 6 months of diagnosis. Of those with imaging results available to view, n=68 were found to have lytic lesions; 7.6% among Group 1, 6.9% among Group 2, 24.9% among Group 3 (p<0.001 comparing Groups 1+2, 7.5%, vs Group 3, 24.9%). Discussion This study used a multifaceted approach to identify potential SMM cases from a large real-world clinical population in an integrated health system. We used an approach similar to prior SMM epidemiological studies and also included those with physician visit notes specifically containing the word 'smoldering' within the text. The vast majority of our cohort had BMPC between 10 and 60%, but those who received treatment within 1 year had greater BMPC and a higher proportion of lytic lesions. This suggests those who received treatment, Group 3, may have actually had a MM diagnosis, and physician visit notes containing the word 'smoldering' may have been intended to communicate something other than a SMM diagnosis. Further analyses will determine the effectiveness of each approach by confirming SMM cases according to the International Myeloma Working Group diagnostic criteria with incorporation of laboratory data and additional clinical findings. Among confirmed cases of SMM, the rate of progression to MM and the severity of end-organ damage at time of progression will be assessed. Figure 1 Figure 1. Disclosures Lo: Novartis: Research Funding; Bristol-Myers-Squibb: Research Funding; CSL-Bering: Research Funding.

An Unexplained Hyperphosphatemia in an Hispanic Woman , a Diagnosis Challenge

Introduction Hyperphosphatemia could be a finding in renal failure, tumor lysis syndrome, hypoparathyroidism, and ingestion of exogenous phosphate. We present the case of a woman with hyperphosphatemia in which we finally diagnosed multiple myeloma, serum phosphate level achieved normal range after chemotherapy started. Although hyperphosphatemia in multiple myeloma is a very rare finding, there are some reports. The proposed mechanisms include a large amount of paraproteins that interferes with phosphorus level determination showing a false increased level. When samples have been deproteinated before analysis, serum phosphorus level can decrease obtaining a true level. This case reminds clinicians the importance of seeking additional causes for abnormal phosphorus levels before starting treatments that could lead to hypophosphatemia. Case report An hispanic woman at the 7th decade of life that only suffered from controlled hypothyroidism, who assisted with complaints of axial pain mainly in thoracic and lumbar segments. She denied neurological and B symptoms. She had a CT scan performed and was referred to the hematology service.On clinical examination we didn't find any neurological signs, no megalies and no palpable nodes. The patient brought a CT spine scan showing thoracic images suggestive of mets with collapse of 50% in T12-L1 and a mass in S2.With these findings we decided to start intrahospitalary studies for excluding malignancy.Her relevant laboratories were: creatinine 0,7, BUN 25, Hemoglobin 9 gr/dl VCM 102 WBC 3330 Granulocytes 55% Platelet 222.000, UN 10,7, albumin 2.8, Lactate dehydrogenase 425. A series of labs seeking secondary causes of malignancy was made including plasmatic cell neoplasie.The hepatic function was normal but an unusually high Phosphorus level was detected (19,6) with normal calcemia (8.98), the tumoral biomarkers were in normal range (CEA, CA 19-9, Ca 125, AFP) and an elevated B2 microglobulin (8) was found. Additional labs included bence jones protein and PTH, both in normal range. A new Thoracic CT described mosaic infiltrates and an extensive bone involvement suggestive of lytic metastatic changes. The abdomen CT showed multiple lytic lesions in lumbo-sacral spine and pelvis, The skull radiography had lytic lesions too. The nephrology service was required by the Hyperphosphatemia and they asked about external intake of phosphorus finding that she was taking "hydrolyzed collagen", so they started iv fluid and chelators (aluminium hydroxide and no calcium chelators).Because of unresponsive hyperphosphatemia, nephrology started hemodialysis.Hematology found high IgG levels (5500) concluding the need for bone marrow studies . Finally a the bone marrow study was performed and prescribed steroids on suspicion of Multiple myeloma. Until this day the Phosphorus level still remained in high levels (17,7) despite hemodialysis sessions. The bone marrow study revealed a plasmatic cell population of 28,9% with big and abundant cytoplasm, some of them with binucleations suggestive of infiltration by plasmatic cell neoplasie. The seric electrophoresis revealed a paraprotein (seric protein of 9,3 with a monoclonal peak of gamma region of 3,4 gr/dl), the seric immunofixation was positive for a monoclonal IgG lambda component. With this report we began chemotherapy treatment for Myeloma with CyBorD regimen (Cyclophosphamide, Bortezomib, dexamethasone). After treatment was initiated, phosphorus level began to lower and achieved normal range (4.28) in the first two weeks. Then she was discharged to continue outpatient management. Nowadays she is receiving her 3rd chemotherapy cycle without complications, her phosphorus level still remains within normality. Conclusions Spurious hyperphosphatemia in patients with paraproteinemias like multiple myeloma can occur. The IgG monoclonal can interfere with the phosphomolybdate principle used in the assay of serum phosphate on most automated chemistry analysers. For labs which do not have a multilayered film technology based system, a serial dilution analysis of the suspected analyte could be performed. Disclosures No relevant conflicts of interest to declare.

Real-World Retrospective Study of 46 Patients with Macrofocal Multiple Myeloma (MFMM)

Real-world retrospective study of 46 patients with Macrofocal multiple myeloma (MFMM) Introduction: Multiple myeloma is a clonal plasma cell malignant neoplasm characterized by bone disease and marrow involvement. However, we found that some myeloma patients presented multiple lytic lesions, but didn't meet the diagnostic criteria of at least 10% clonal plasma cells in the bone marrow. And these patients were always diagnosed with myeloma by biopsy-proven plasmacytomas. This special myeloma entity has been called macrofocal multiple myeloma (MFMM) [1-2]. Considering that the data of this rare myeloma entity are limited, it is of great significance to investigate the clinical characteristics, genetic abnormality, treatment response and prognosis of MFMM patients. Methods: Based on the definition (BMPCs<20% and multiple lytic lesions/plasmacytomas, without anemia, renal insufficiency or hypercalcemia) [3]，we identified 46 MFMM patients among 791 myeloma patients(5.8%) diagnosed at out hospital between January 2013 and December 2019. In the same period with same therapies, other 92 typical myeloma patients were selected as the control group. Results: Patient characteristics and comparisons between MFMM patients and the control group are depicted in Table 1. Of the 46 MFMM patients, 82.6% were <65 years and 73.9% had at least 4 lytic lesions. And the incidence of plasmacytomas in MFMM patients was significantly higher than the control group (43.5% vs 18.5%, p<0.05). According to the international staging (ISS) and the Revised ISS, advanced stage patients in the MFMM group was less common than controls (p<0.05). Regarding to the cytogenetics, the high-risk features was infrequent in patients with MFMM compared to typical myeloma patients (15.8% vs 32.2%, p=0.058). And t (11;14) could be observed in 32.4% MFMM patients and 9.4% myeloma patients (p<0.05). The treatment patterns of the two groups were similar; about 30% of the patients received ASCT, and 80% patients received proteasome-inhibitors based regimen as the induction therapy. Concerning about the best response to treatment, the CR rate of the MFMM group was significantly higher than the controls (78.2% vs 60.8%, p<0.05). As of June 2021, the median follow-up time was 37.9 months. The median progression-free survival in the study and control groups were 77.5 vs 39.8 months, respectively (p<0.05). The overall survival (OS) of MFMM patients was significantly longer than typical myeloma patients during the same period with similar therapies (not reached vs 68.2m, p<0.05). Conclusion: In conclusion, Macrofocal multiple myeloma is a special entity of MM, which is characterized with multiple lytic lesions, more extramedullary diseases, less bone marrow infiltration, and fewer adverse features. And the MFMM patient could achieve deep remission and prolonged OS in the era of novel agents. References: [1] Dimopoulos MA, Pouli A, Anagnostopoulos A, et al. Macrofocal multiple myeloma in young patients: a distinct entity with favorable prognosis. Leuk Lymphoma. 2006;47(8):1553-1556. [2] Rajkumar SV, Dimopoulos MA, Palumbo A, et al. International Myeloma Working Group updated criteria for the diagnosis of multiple myeloma. Lancet Oncol. 2014;15(12):e538-e548. [3] Katodritou E, Kastritis E, Gatt M, et al. Real-world data on incidence, clinical characteristics and outcome of patients with macrofocal multiple myeloma (MFMM) in the era of novel therapies: A study of the Greco-Israeli collaborative myeloma working group. Am J Hematol. 2020;95(5):465-471. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Osteolytic Bone Lesions in Patients with Primary Myelofibrosis: A Systematic Review

Background: Philadelphia negative Myeloproliferative neoplasms classically characterized by excess production of terminal myeloid cells in the peripheral blood. Among this group, primary myelofibrosis is the least common and usually carries the worst prognosis. Bone involvement in primary myelofibrosis has many forms and tend to manifest as osteosclerotic lesions in vast majority of cases, however osteolytic lesions are reported in exceptional occasions. In this review, we tried to shed the light on this rare association. Methods: We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the English literature (Google scholar, PubMed, and SCOPUS) for studies, reviews, case series, and case reports about patient with myelofibrosis who develop lytic bone lesion. We used the terms in combination: "Myelofibrosis'" or "Primary myelofibrosis" OR "chronic idiopathic myelofibrosis" OR "agnogenic myeloid metaplasia" and "Osteolytic bone lesion", "Osteolytic lesion", "lytic bone lesion". The review included patients with primary myelofibrosis confirmed by biopsy. The reference lists of the included studies were scanned for any additional articles. The search included all articles published up to 10th April 2021. Two independent reviewers screened the titles and abstracts of the records independently and papers unrelated to our inclusion criteria were excluded. A total of 13 articles were included in the review. Results : Total of 13 patients were included in the review. 7 patients were males, male to female ratio almost of 1:1. The mean age at time of diagnosis was 57.69 year, only two cases were diagnosed at young age, however the majority have osteolytic bone lesion at age above 50 years (12/13) of cases. The mean time between the diagnosis of primary myelofibrosis until the osteolytic bone lesion capturing was approximately 8.8 years. 9 out of 13 patients have painful bone lesion, others were incidental finding during a scan for other reasons. All patients have significant splenomegaly. All patients had the lytic lesion detected on x ray, and 2 patients had confirmed findings on magnetic resonance imaging (MRI). The most common affected bones were the vertebrae, pelvis, ribs, humerus then the scapula, femur and skull and less frequently wrist bones and calcaneus. Only one case has reported involvement of the tibia and fibula. The shape, the extension and the numbers of lesion were variable, some showed cortical sparing and others come with cortical destruction. 10 out of 13 cases have confirmed the nature of the osteolytic lesion containing hematopoietic stem cells with or without fibrosis, 2 cases were positive for JAK2 mutation. 2 patients have received ruxolitinib, one of them preceded with bone marrow transplant, others received nonspecific therapies. Discussion: The hyperdynamic ineffective bone marrow can have a negative impact on the bone structure resulting in different types of bone pathology including lytic and sclerotic lesions. The exact mechanism beyond developing lytic lesions is not fully studied, observations revealed two possible causes: systemic inflammation and direct mechanical compression from para-osseus lymph nodes. Lesions prevalence was equal in both genders which can be attributable to a small sample size, in addition, most of the patients were in advanced stages when the lytic lesions discovered and this observation can be explained by the needed time to generate extramedullary hematopoiesis and its subsequent effect on bone structure. The variation in time between the diagnosis of PMF and development of osteolytic bone lesions could be due to the indolent phase of the disease, in which patients can survive for decades without symptoms. Until recently the treatment of myelofibrosis was supportive, but after establishing the JAK2-stat pathway role in myeloproliferative disorders the FDA approved ruxolitinib a JAK2 inhibitor which shows not only survival benefit but also has a significant impact on the resolution of the lytic bone lesions as well. conclusion Osteolytic bone lesions in patients with primary myelofibrosis is extremely rare finding, and noticed shortly after diagnosis in elderly and after longer duration in young patients. The lytic lesion seems to have a bad prognostic value as we can notice 11 out of 13 patients died within one year of detection. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

P085 Chronic recurrent multifocal osteomyelitis: about 2 cases

Background Chronic recurrent multifocal osteomyelitis (CRMO) also known as aseptic osteomyelitis is a rare auto-inflammatory disease with an incidence estimated at 4/100 000 population [1]. The aim of our work was to report two cases of CRMO that illustrate challenges in the diagnosis of this rare disease. Method We report the case of two patients diagnosed with CRMO. Clinical, biological and radiological data as well as disease outcomes were described. We also collected data about treatment modalities. Results Two patients aged of 7 and 10 years respectively, without any notable pathological history, presented recurrent episodes multifocal painful swelling of limbs. In the first case, the symptoms concerned the left ankle and knee as well as the left hip, all associated with lameness and an altered general condition, with neither fever nor skin manifestations. In the second case, the swelling involved the right shoulder, right hip and the left ankle. There was no elevated CRP or ESR in any of patients. Immunological status (RF, anti-CCP, AAN) as well as the HLA-B27 antigen test were negative. In the first patient, standard radiographs showed lytic lesions of the proximal metaphysis of the tibia, the greater trochanter and the left lateral malleolus. MRI of the pelvis, knee, and sternum of the first patient revealed edematous involvement of the left greater trochanter, the right ilium, the proximal metaphyseal region of the tibia and the right edge of the sternum, whereas in the second patient, a whole-body MRI showed inflammatory signs over the left greater trochanter, the insertion of the gluteus medius and obturator externus, right trochanteric bursitis and oedema of the entire right ilium. In the first patient, bone scintigraphy showed intense uptake of radioisotopes in the left ilium, the 7 th right costo-vertebral junction, the trochanteric mass, the upper end of the tibia and the lower end of the left fibula. Bone biopsy showed bone remodeling in both cases without evidence of infection or tumor. The diagnosis of CRMO was retained, supported by the prompt response to NSAIDs and short-term corticosteroid therapy. However, the second patient presented, 8 years later, pain in the sterno-clavicular joint as well as the right hip. A relapse of the disease was confirmed by MRI. Therapeutic escalation with zoledronic acid 0.025 mg/kg intravenous infusion every six months allowed the resolution of the symptoms. Conclusion These observations illustrated a rare disorder in children, characterized by lytic lesions predominantly in the metaphysis of long bones. Bone scintigraphy allowed an early assessment of disease extension and histological examination ruled out a malignant tumor and an infection. The first-line treatment is anti-inflammatory drugs. In case of failure, bisphosphonates seem to be effective.

Epithelioid Angiosarcoma of the Tibia: A Case Report and Literature Review

Background：Epithelioid angiosarcoma (EA) is characterized by epithelioid-like neoplastic cells. In fact, there is little literature regarding EA of bone. Accordingly, this study presents an imaging analysis of a 66-year-old man who suffered from EA in his right tibia.Case presentation: A 66-year-old man developed right ankle pain four months prior to initial evaluation at our institute, which was progressively worsening for six days. All laboratory data were within the reference ranges. Plain radiographs and computed tomography (CT) revealed osteolytic lesions with multiple separations in the distal tibia, measuring 7.9 cm × 4.6 cm × 4.4 cm in size. The lytic lesions were ill-circumscribed and lacked marginal sclerosis. Punctate irregular calcifications and low-density areas were observed within lesion's areas. The cortical bone was irregularly thinned and was discontinuous. On magnetic resonance imaging (MRI), the lesions were heterogeneous. Immunohistochemically, the tumor cells expressed the vascular markers CD31, CD34, and factor VIII and revealed 5% positivity for Ki67. Finally, the patient was diagnosed with EA of bone.Conclusions: We reported a case of EA that occurred in the right tibia and summarized the imaging features of EA by reviewing the literature. Although pathological examination remains the gold standard for diagnosing EA, specific imaging features may assist in diagnosis.