Bone remineralization of lytic lesions in multiple myeloma - The Arkansas experience.

Multiple myeloma (MM) patients frequently present with extensive osteolytic bone lesions. However, the impact of myeloma treatment on focal lytic lesion remineralization has not been extensively studied. In this study, the effect of anti-myeloma treatment on the extent of bone remineralization was examined and potential mediators identified. Newly diagnosed MM patients enrolled in the Total Therapy 4 and 5 (TT4; n = 231, TT5; n = 64) protocols were longitudinally evaluated for changes in radiological parameters for a median of 6.1 years. Bone remineralization was defined as a sclerotic CT change within the lytic lesion and quantified as a percentage of remineralization, using the initial lesion size as a reference. Such changes were correlated to clinical and biochemical parameters, and the gene expression profile of bone marrow biopsy. Overall, remineralization occurred in 72% of patients (213/295). Of those patients that experienced remineralization, 36% (107/295) achieved at least 25% of bone remineralization. Patients with high-risk disease defined by gene expression profile signature (GEP70 ≥ 0.66) experienced significant remineralization compared to low-risk MM. Female patients were also more likely to experience bone remineralization and in a shorter median time (2.0 vs. 3.3 y). Factors such as serum alkaline phosphatase along with high levels of RUNX2 and SOX4 gene expression correlated with increasing extent of bone remineralization. This analysis demonstrated significant remineralization of lytic lesions in MM patients treated on TT clinical trials. While the underlying mechanism remains elusive these findings support the hypothesis that patient baseline bone-related factors play a fundamental role in the skeletal repair of bone lesions in MM that provide new opportunities for improving patient outcomes.

Lack of Spleen Signal on Diffusion Weighted MRI is associated with High Tumor Burden and Poor Prognosis in Multiple Myeloma: A Link to Extramedullary Hematopoiesis?

Due to the low frequency of abnormalities affecting the spleen, this organ is often overlooked during radiological examinations. Here, we report on the unexpected finding, that the spleen signal on diffusion-weighted MRI (DW-MRI) is associated with clinical parameters in patients with plasma cell dyscrasias. Methods: We investigated the spleen signal on DW-MRI together with clinical and molecular parameters in 295 transplant-eligible newly diagnosed Multiple Myeloma (NDMM) patients and in 72 cases with monoclonal gammopathy of undetermined significance (MGUS). Results: Usually, the spleen is the abdominal organ with the highest intensities on DW-MRI. Yet, significant signal loss on DW-MRI images was seen in 71 of 295 (24%) NDMM patients. This phenomenon was associated with the level of bone marrow plasmacytosis (P=1x10-10) and International Staging System 3 (P=0.0001) but not with gain(1q), and del(17p) or plasma cell gene signatures. The signal was preserved in 72 individuals with monoclonal gammopathy of undetermined significance and generally re-appeared in MM patients responding to treatment, suggesting that lack of signal reflects increased tumor burden. While absence of spleen signal in MM patients with high risk disease defined a subgroup with very poor outcome, re-appearance of the spleen signal after autologous stem cell transplantation was seen in patients with improved outcome. Our preliminary observation suggests that extramedullary hematopoiesis in the spleen is a factor that modifies the DW-MRI signal of this organ. Conclusions: The DW-MRI spleen signal is a promising marker for tumor load and provides prognostic information in MM.

Skull Base-related Lesions at Routine Head CT from the Emergency Department: Pearls, Pitfalls, and Lessons Learned.

Routine non-contrast material-enhanced head CT is one of the most frequently ordered studies in the emergency department. Skull base-related pathologic entities, often depicted on the first or last images of a routine head CT study, can be easily overlooked in the emergency setting if not incorporated in the interpreting radiologist's search pattern, as the findings can be incompletely imaged. Delayed diagnosis, misdiagnosis, or lack of recognition of skull base pathologic entities can negatively impact patient care. This article reviews and illustrates the essential skull base anatomy and common blind spots that are important to radiologists who interpret nonenhanced head CT images in the acute setting. The imaging characteristics of important "do not miss" lesions are emphasized and categorized by their cause and location within the skull base, and the potential differential diagnoses are discussed. An interpretation checklist to improve diagnostic accuracy is provided. ©RSNA, 2019.

The presence of large focal lesions is a strong independent prognostic factor in multiple myeloma.

Spatial intratumor heterogeneity is frequently seen in multiple myeloma (MM) and poses a significant challenge for risk classifiers, which rely on tumor samples from the iliac crest. Because biopsy-based assessment of multiple skeletal sites is difficult, alternative strategies for risk stratification are required. Recently, the size of focal lesions (FLs) was shown to be a surrogate marker for spatial heterogeneity, suggesting that data from medical imaging could be used to improve risk stratification approaches. Here, we investigated the prognostic value of FL size in 404 transplant-eligible, newly diagnosed MM patients. Using diffusion-weighted magnetic resonance imaging with background suppression, we identified the presence of multiple large FLs as a strong prognostic factor. Patients with at least 3 large FLs with a product of the perpendicular diameters >5 cm2 were associated with poor progression-free survival (PFS) and overall survival (OS; median, 2.3 and 3.6 years, respectively). This pattern, seen in 13.8% of patients, was independent of the Revised International Staging System (RISS), gene expression profiling (GEP)-based risk score, gain(1q), or extramedullary disease (hazard ratio, 2.7 and 2.2 for PFS and OS in multivariate analysis, respectively). The number of FLs lost its negative impact on outcome after adjusting for FL size. In conclusion, the presence of at least 3 large FL is a feature of high risk, which can be used to refine the diagnosis of this type of disease behavior and as an entry criterion for risk-stratified trials.

Characterization of Thyroid Nodules by 4-Dimensional Computed Tomography: Initial Experience.

OBJECTIVE: We aimed to evaluate the use of 4-dimensional computed tomography (4DCT) for characterization of thyroid nodules. METHODS: Our study drew from 100 consecutive patients with primary hyperparathyroidism who underwent 4D parathyroid CT imaging for adenoma localization. Included subjects had tissue sampling of a thyroid nodule within 3 months of 4DCT. RESULTS: Twenty subjects (18 women and 2 men) had thyroid nodules that were pathologically confirmed. Precontrast nodule attenuation was significantly lower in malignant nodules when compared with benign nodules (36 vs 61 HU, P = 0.05). Arterial phase and delayed phase nodule attenuations were not significantly different in malignant and benign nodules (128 vs 144 HU, P = 0.7; 74 vs 98 HU, P = 0.3). CONCLUSIONS: Our initial experience with a small group of patients was unable to support the use of 4DCT for characterizing thyroid nodules; however, precontrast nodule attenuation was significantly lower in malignant nodules when compared with benign nodules.

Root Cause Analysis: An Examination of Odontogenic Origins of Acute Maxillary Sinusitis in Both Immunocompetent & Immunocompromised Patients.

BACKGROUND AND PURPOSE: Dental and periodontal diseases represent important but often overlooked causes of acute sinusitis. Our goal was to examine the prevalence of potential odontogenic sources of acute maxillary sinusitis according to immune status and their associations with sinusitis. MATERIALS AND METHODS: A retrospective review of maxillofacial computed tomography studies from 2013 to 2014 was performed. Each maxillary sinus and its ipsilateral dentition were evaluated for findings of acute sinusitis and dental/periodontal disease. RESULTS: Eighty-four patients (24 immunocompetent, 60 immunocompromised) had 171 maxillary sinuses that met inclusion criteria for acute maxillary sinusitis. Inspection of dentition revealed oroantral fistula in 1%, periapical lucencies in 16%, and projecting tooth root(s) in 71% of cases. Immunocompromised patients were more likely to have bilateral sinusitis than immunocompetent patients (67% vs 33%, P = 0.005). A paired case-control analysis in a subset of patients with unilateral maxillary sinusitis (n = 39) showed a higher prevalence of periapical lucency in association with sinuses that had an air fluid level-29% of sinuses with a fluid level had periapical lucency compared with 12% without sinus fluid (P = 0.033). CONCLUSIONS: Potential odontogenic sources of acute maxillary sinusitis are highly prevalent in both immunocompetent and immunocompromised patients, although the 2 patient populations demonstrate no difference in the prevalence of these potential odontogenic sources. Periapical lucencies were found to be associated with an ipsilateral sinus fluid level. Increased awareness of the importance of dental and periodontal diseases as key components of maxillofacial computed tomography interpretation would facilitate a more appropriate and timely treatment.

Features of infratentorial-predominant posterior reversible encephalopathy syndrome.

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic process that typically occurs in the setting of immune dysregulation. In contrast to the characteristic pattern involving parieto-occipital and posterior frontal regions, predominant involvement of the infratentorial brain occurs in a minority of PRES patients. We examined six patients with infratentorial predominant posterior reversible encephalopathy syndrome (IPPRES) relative to those with typical PRES in terms of clinical factors of toxicity and outcomes. We review the current understanding of PRES pathophysiology. An institutional database of PRES patients was created through an IRB-approved search of the electronic record from 2007 to 2012. MR images were reviewed and classified by two neuro radiologists. Clinical data including laboratory data, blood pressure, and discharge outcome were collected through review of existing electronic medical records. Characteristics of the two groups were compared. Six cases among 80 PRES patients displayed an atypical distribution of signal abnormality predominantly involving the infratentorial brain. In IPPRES patients, signal abnormalities within the supratentorial brain, when present, showed a predominantly central distribution rather than the typical peripheral distribution. IPPRES patients showed higher rates of extreme hypertension, renal dysfunction, abnormal serum calcium, and abnormal serum magnesium relative to typical PRES patients. Outcomes were similar between the two groups. In our small series, IPPRES differs from typical PRES patients not only in the distribution of imaging abnormalities but also in rates of extreme hypertension and several laboratory indices. Despite these differences, clinical outcome in the IPPRES group was similar to that of typical PRES.

Lithium toxicity and PRES: a novel association.

We report two cases of posterior reversible encephalopathy syndrome (PRES) occurring in association with supra-therapeutic serum lithium levels. Although the neurologic manifestations of lithium toxicity are well known, this is, to our knowledge, the first report describing a link between lithium toxicity and PRES. We discuss the current understanding of the pathogenesis of PRES and suggest mechanisms by which lithium may play a role in its development.

Elevation of serum lactate dehydrogenase at posterior reversible encephalopathy syndrome onset in chemotherapy-treated cancer patients.

The pathophysiology of posterior reversible encephalopathy syndrome (PRES) is incompletely understood; however, an underlying state of immune dysregulation and endothelial dysfunction has been proposed. We examined alterations of serum lactate dehydrogenase (LDH), a marker of endothelial dysfunction, relative to the development of PRES in patients receiving chemotherapy. A retrospective Institutional Review Board approved database of 88 PRES patients was examined. PRES diagnosis was confirmed by congruent clinical diagnosis and MRI. Clinical features at presentation were recorded. Serum LDH values were collected at three time points: prior to, at the time of, and following PRES diagnosis. Student's t-test was employed. LDH values were available during the course of treatment in 12 patients (nine women; mean age 57.8 years [range 33-75 years]). Chemotherapy-associated PRES patients were more likely to be normotensive (25%) versus the non-chemotherapy group (9%). LDH levels at the time of PRES diagnosis were higher than those before and after (p=0.0263), with a mean difference of 114.8 international units/L. Mean time intervals between LDH measurement prior to and following PRES diagnosis were 44.8 days and 51.4 days, respectively. Mean elapsed time between last chemotherapy administration and PRES onset was 11.1days. In conclusion, serum LDH, a marker of endothelial dysfunction, shows statistically significant elevation at the onset of PRES toxicity in cancer patients receiving chemotherapy. Our findings support a systemic process characterized by endothelial injury/dysfunction as a factor, if not the prime event, in the pathophysiology of PRES.

Standard and novel imaging methods for multiple myeloma: correlates with prognostic laboratory variables including gene expression profiling data.

Multiple myeloma causes major morbidity resulting from osteolytic lesions that can be detected by metastatic bone surveys. Magnetic resonance imaging and positron emission tomography can detect bone marrow focal lesions long before development of osteolytic lesions. Using data from patients enrolled in Total Therapy 3 for newly diagnosed myeloma (n=303), we analyzed associations of these imaging techniques with baseline standard laboratory variables assessed before initiating treatment. Of 270 patients with complete imaging data, 245 also had gene expression profiling data. Osteolytic lesions detected on metastatic bone surveys correlated with focal lesions detected by magnetic resonance imaging and positron emission tomography, although, in two-way comparisons, focal lesion counts based on both magnetic resonance imaging and positron emission tomography tended to be greater than those based on metastatic bone survey. Higher numbers of focal lesions detected by magnetic resonance imaging and positron emission tomography were positively linked to high serum concentrations of C-reactive protein, gene-expression-profiling-defined high risk, and the proliferation molecular subgroup. Positron emission tomography focal lesion maximum standardized unit values were significantly correlated with gene-expression-profiling-defined high risk and higher numbers of focal lesions detected by positron emission tomography. Interestingly, four genes associated with high-risk disease (related to cell cycle and metabolism) were linked to counts of focal lesions detected by magnetic resonance imaging and positron emission tomography. Collectively, our results demonstrate significant associations of all three imaging techniques with tumor burden and, especially, disease aggressiveness captured by gene-expression-profiling-risk designation. (Clinicaltrials.gov identifier: NCT00081939).

Rosette-forming glioneuronal tumor of the fourth ventricle.

We present a case of a 22-year-old asymptomatic female whose CT study (performed following trauma) incidentally discovered a posterior fossa mass. The lesion was further evaluated with a MRI study, and (following discussion with the patient and her family) elective surgical resection of the lesion was performed. On pathology, histological evaluation revealed a diagnosis of rosette-forming glioneuronal tumor of the fourth ventricle. RGNT of the fourth ventricle or posterior fossa should always be considered in the differential diagnosis of infratentorial lesions, especially in young adults.

Endolymphatic sac tumor.

Endolymphatic sac tumor is an uncommon, locally aggressive tumor. The tumor is located in the medial and posterior petrosal bone region and may involve the dura. A hypervascular tumor involving the endolymphatic sac with destructive changes, it involves the bone and may show reactive new bone formation. Diagnosis is based on clinical, radiological, and pathological correlation. We present a case of endolymphatic sac tumor in a 24-year-old female who presented with a chief complaint of hearing loss.

Cerebellopontine angle tumor in a patient with a maternally inherited SDHD gene mutation.

Acoustic neuromas are the most common tumor in the cerebellopontine angle (CPA) but are rare in the general population. Paragangliomas are rarer still and, in a minority of cases (20%), are known to be caused by errors in the SDHD gene. Mutations in this gene are highly penetrant when inherited paternally but not maternally. We present the first reported case of a patient with a CPA tumor and a maternally inherited SDHD gene mutation.

Magnetic resonance imaging in multiple myeloma: diagnostic and clinical implications.

PURPOSE: Magnetic resonance imaging (MRI) permits the detection of diffuse and focal bone marrow infiltration in the absence of osteopenia or focal osteolysis on standard metastatic bone surveys (MBSs). PATIENTS AND METHODS: Both baseline MBS and MRI were available in 611 of 668 myeloma patients who were treated uniformly with a tandem autologous transplantation-based protocol and were evaluated to determine their respective merits for disease staging, response assessment, and outcome prediction. RESULTS: MRI detected focal lesions (FLs) in 74% and MBS in 56% of imaged anatomic sites; 52% of 267 patients with normal MBS results and 20% of 160 with normal MRI results had FL on MRI and MBS, respectively. MRI- but not MBS-defined FL independently affected survival. Cytogenetic abnormalities (CAs) and more than seven FLs on MRI (MRI-FLs) distinguished three risk groups: 5-year survival was 76% in the absence of both more than seven MRI-FLs and CA (n = 276), 61% in the presence of one MRI-FL (n = 262), and 37% in the presence of both unfavorable parameters (n = 67). MRI-FL correlated with low albumin and elevated levels of C-reactive protein, lactate dehydrogenase, and creatinine, but did not correlate with age, beta-2-microglobulin, and CA. Resolution of MRI-FL, occurring in 60% of cases and not seen with MBS-defined FL, conferred superior survival. CONCLUSION: MRI is a more powerful tool for detection of FLs than is MBS. MRI-FL number had independent prognostic implications; additionally, MRI-FL resolution identified a subgroup with superior survival. We therefore recommend that, in addition to MBS, MRI be used routinely for staging, prognosis, and response assessment in myeloma.

Multiple myeloma invasion of the central nervous system.

BACKGROUND: Although neurologic manifestations often complicate the course of patients with multiple myeloma (MM), direct central nervous system invasion is rare. OBJECTIVE: To describe the neurologic symptoms and signs, imaging, cerebrospinal fluid findings, and the clinical course of patients with central nervous system myeloma invasion, all of whom had leptomeningeal myelomatosis. DESIGN AND PARTICIPANTS: Review of 23 patients with MM and leptomeningeal myelomatosis proven by malignant plasma cells in their cerebrospinal fluid. SETTING: Tertiary-care university medical center. RESULTS: Twenty-one patients had advanced-stage MM. Leptomeningeal myelomatosis was diagnosed up to 29 months (median, 13 months) after diagnosis of MM. Symptoms precipitating neurologic evaluation included manifestations of diffuse cerebral dysfunction, cranial nerve palsies, and spinal radiculopathies. Cerebrospinal fluid was abnormal in all patients, usually exhibiting pleocytosis and elevated protein content, plus positive cytologic findings. Specific magnetic resonance imaging findings suggestive of central nervous system invasion were found in 70% of the patients. These included leptomeningeal contrast enhancement and evidence of meningeal-based lesions sometimes masquerading as intraparenchymal lesions. Despite aggressive systemic and local treatment, the outcome was poor, reflecting the aggressiveness of the underlying MM. CONCLUSION: Leptomeningeal myelomatosis, although rare, should be considered in patients with MM and symptoms suggestive of widespread nervous system involvement.

Myeloma of the central nervous system: strong association with unfavorable chromosomal abnormalities and other high-risk disease features.

Involvement of the central nervous system (CNS) by multiple myeloma, defined by the detection of malignant plasma cells in the cerebrospinal fluid in the presence of suggestive symptoms, is considered extremely rare. We present the characteristics of 25 such patients (18 previously reported) intended to receive high-dose treatment at the University of Arkansas over the last 12 years; an extensive review of the published literature since 1968, including 71 patients, is also presented. In both patient groups, high tumor burden was overwhelmingly present while circulating plasma cells were detected in a significant proportion of cases. We also observed a strong association of CNS involvement with unfavorable cytogenetic abnormalities (especially translocations and deletion of the chromosome 13), plasmablastic morphology and additional extramedullary myeloma manifestations. The presence of these features should alert clinicians to the possibility of CNS involvement. The prognosis of such patients is poor despite aggressive systemic and local treatment and reflects the underlying disease biology. Application of allogeneic transplantation and administration of prophylactic CNS treatment are also discussed. Further elucidation of the factors predisposing patients with high-risk disease features to CNS myeloma involvement is needed.

Comprehensive review of intracranial chordoma.

Intracranial chordoma is a locally aggressive and relatively rare tumor of the skull base that is thought to originate from embryonic remnants of the primitive notochord. Both computed tomography (CT) and magnetic resonance (MR) imaging are usually required for evaluation of intracranial chordomas due to bone involvement and the proximity of these tumors to many critical soft-tissue structures. At CT, intracranial chordoma typically appears as a centrally located, well-circumscribed, expansile soft-tissue mass that arises from the clivus with associated extensive lytic bone destruction. However, MR imaging is the single best imaging modality for both pre- and posttreatment evaluation of intracranial chordoma. On T1-weighted MR images, intracranial chordomas demonstrate intermediate to low signal intensity and are easily recognized within the high-signal-intensity fat of the clivus. On T2-weighted MR images, they characteristically demonstrate very high signal intensity, a finding that likely reflects the high fluid content of vacuolated cellular components. Moderate to marked enhancement is common and often heterogeneous on contrast material-enhanced images. Combination treatment with radical surgical resection and proton beam radiation therapy achieves the best results.