Non-Hodgkin lymphoma involving the parotid gland: CT and MR imaging findings.
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ABSTRACT:
SUBMITTER: Zhu L
PROVIDER: S-EPMC3828024 | biostudies-other | 2013
REPOSITORIES: biostudies-other
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Project description:BackgroundTarsal coalitions affect up to 13% of the population and can be a cause of chronic ankle and hindfoot pain. They can be subdivided as osseous, cartilaginous, or fibrous types, each with unique radiographic, CT, and MR imaging findings. In particular, MR imaging offers the unique ability to determine the exact type of tarsal coalition that is present as well as whether any associated soft tissue abnormalities are present.Questions/purposesThe purposes of this paper were to (1) review the anatomy of the hindfoot; (2) review the radiographic, CT, and MR imaging findings of tarsal coalitions; and (3) review the imaging appearance of the specific types of tarsal coalitions.MethodsOnline searches were performed using Google Scholar with the search criteria of "tarsal coalition," "hindfoot anatomy," and "subtalar coalition," and limiting the searches to papers published in the last 10 years in major radiology journals.ResultsThe anatomy of the hindfoot is complex but essential to understand. There are various radiographic, CT, and MR imaging findings that can be consistently noted in cases of tarsal coalition. The specific types of tarsal coalition demonstrate characteristic imaging findings.ConclusionsKnowledge of the normal anatomy of the foot, in particular the hindfoot, combined with the knowledge of the imaging characteristics of different histologic subtypes of coalitions (osseous, cartilaginous, and fibrous) is essential for interpreting radiographic, CT, and MR images of the ankle and foot.
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Project description:Background and purposeSinonasal organized hematoma (OH) is an uncommon, nonneoplastic benign condition that can be locally aggressive. The purpose of this work was to characterize the CT and MR imaging findings of sinonasal OH.Materials and methodsCT (n = 11) and MR (n = 10) images of 12 patients (9 men and 3 women; mean age, 41 years; range, 12-76 years) with pathologically proved sinonasal OH were retrospectively reviewed. Particular attention was put on the location, shape, size, extent, internal architecture, and enhancement pattern of the lesion and associated sinus wall change.ResultsThe lesions were seen as an expansile (n = 9) or nonexpansile (n = 3) mass, ranging in size from 2.2 to 6.0 cm (mean, 4.2 cm), primarily involving the maxillary sinus (n = 11) or nasal cavity (n = 1) unilaterally. The ipsilateral nasal cavity was also involved in 9 of 11 maxillary sinus lesions. Smooth sinus wall erosion other than the medial maxillary sinus wall was noted in 8 lesions. The internal architecture was best displayed on T2-weighted MR images on which all of the lesions were seen as a mixture of marked heterogeneous hypointensity and isointensity, surrounded by a hypointense peripheral rim, reflecting histologic heterogeneity of the lesion composed of hemorrhage, fibrosis, and neovascularization. Marked irregular nodular, papillary, or frondlike enhancement at the areas of neovascularization was also a typical finding seen in all of the lesions.ConclusionAn expansile soft tissue mass, smooth sinus wall erosion, marked heterogeneous signal intensity with a hypointense peripheral rim on T2-weighted MR images, and marked irregular nodular, papillary, or frondlike enhancement are characteristic CT and MR imaging findings of sinonasal OH.
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Project description:Background and purposeLarge arachnoid granulations (AG) within the dorsal superior sagittal sinus (SSS) have been incompletely characterized and can be confused with pathology. This report reviews the characteristics of these anatomic structures to establish common imaging features that allow differentiation from pathology.Materials and methodsTwelve cases of large AG in the dorsal SSS are presented, identified by MR imaging. Signal intensity characteristics, size, location, venographic appearance, and association with adjacent venous and osseous structures were documented.ResultsA defect in the dura of the SSS was seen in all of the cases communicating with the subjacent subarachnoid space. The average size of the AG was 8.1 x 9.4 x 10.0 mm (range, 4-19 mm). Ten produced calvarial remodeling, and 11 were in the direct vicinity of the lambda. On T2-weighted images, all were hyperintense to the brain. On T1-weighted images, 8 were hypointense and 4 were hypointense with mixed areas of isointense signal intensity. All of the AGs were associated with cortical venous structures entering the sinus. On MR venography, AGs appeared as focal protrusions into the sinus, displacing, distorting, and narrowing the sinus lumen. Seven patients had headache without other visible cause on MR imaging, and 4 were initially interpreted as thrombosis or tumor.ConclusionLarge AGs can occur in the dorsal SSS. They are well-defined projections of the subarachnoid space into the sinus, can cause luminal narrowing and calvarial remodeling, and have typical signal intensity characteristics, position, and morphology differentiating them from other pathology. Association with patient symptoms is uncertain.
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Project description:The segmentation of organs at risk is a crucial and time-consuming step in radiotherapy planning. Good automatic methods can significantly reduce the time clinicians have to spend on this task. Due to its variability in shape and low contrast to surrounding structures, segmenting the parotid gland is challenging. Motivated by the recent success of deep learning, we study the use of two-dimensional (2-D), 2-D ensemble, and three-dimensional (3-D) U-Nets for segmentation. The mean Dice similarity to ground truth is ?0.83 for all three models. A patch-based approach for class balancing seems promising for false-positive reduction. The 2-D ensemble and 3-D U-Net are applied to the test data of the 2015 MICCAI challenge on head and neck autosegmentation. Both deep learning methods generalize well onto independent data (Dice 0.865 and 0.88) and are superior to a selection of model- and atlas-based methods with respect to the Dice coefficient. Since appropriate reference annotations are essential for training but often difficult and expensive to obtain, it is important to know how many samples are needed for training. We evaluate the performance after training with different-sized training sets and observe no significant increase in the Dice coefficient for more than 250 training cases.
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Project description:Fibrous Solitary Tumors are infrequent neoplasms originating from mesenchymal tissues, most commonly arising from the visceral pleura and frequently exhibiting a benign behavior. Extra-pleural localization is unusual and the site of origin of these tumors from the parenchyma of the parotid gland is considered extremely rare. We report the case of a 66-years old woman with non-painful slow-growing left latero-cervical mass, who underwent a gadolinium-enhanced Magnetic Resonance Imaging showing a mass originating from the deep lobe of the parotid gland extending into the retro-pharyngeal space. After a total parotidectomy with tumor excision, a diagnosis of histologically proven fibrous solitary tumor of the parotid gland was made. Two years later, CT scan showed post-operative recurrence and further satellite localization in the neck, distant from the initial mass. We performed a literature review of the published similar cases, in order to clinicopathological and imaging features of this rare entity.
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Project description:Background and purposeThe surgical approach to parotid tumors is different for benign and malignant neoplasms, but the clinical symptoms do not correlate well with histology. Difficulties in tumor classification also arise in imaging modalities, in which sonography has the lowest and MR imaging, the highest accuracy. The purpose of this study was to review our experience using conventional MR imaging of the neck in the evaluation of parotid tumors and to evaluate which MR imaging findings are best able to predict malignant histology.Materials and methodsEighty-four consecutive patients (43 males, 41 females; median age, 56 years; range, 9-85 years) with parotid gland tumors who underwent MR imaging before surgery were prospectively included in the present study and retrospectively analyzed. Histology was available for all tumors. We analyzed the following MR imaging parameters: signal intensity, contrast enhancement, lesion margins (well-defined versus ill-defined), lesion location (deep/superficial lobe), growth pattern (focal, multifocal, or diffuse), and extension into neighboring structures, perineural spread, and lymphadenopathy.ResultsThe 57 (68%) benign and 27 (32%) malignant tumors consisted of 29 pleomorphic adenomas, 17 Warthin tumors, 11 various benign tumors, 5 mucoepidermoid carcinomas, 3 adenoid cystic carcinomas, 1 acinic cell carcinoma, 1 carcinoma ex pleomorphic adenoma, 9 metastases, and 8 various malignant neoplasms. Specific signs predictive of malignancy were the following: T2 hypointensity of the parotid tumor (P = .048), ill-defined margins (P = .001), diffuse growth (P = .012), infiltration of subcutaneous tissue (P = .0034), and lymphadenopathy (P = .012).ConclusionsLow signal intensity on T2-weighted images and postcontrast ill-defined margins of a parotid tumor are highly suggestive of malignancy.
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Project description:Purpose:While metastasis to the thyroid from a primary cancer remote to the thyroid is uncommon, current imaging techniques have improved detection of these intrathyroid metastases. The purpose of this study was to evaluate the 18F-PET/CT appearance of intrathyroid metastases and assess the impact of detection on patient management. Methods:The 18F-PET/CT appearance of intrathyroid metastasis, including standardized uptake value (SUV), disease extent, and the effect on patient management following diagnosis were retrospectively reviewed. Inclusion criteria included 18F-PET/CT imaging and diagnosis of the intrathyroid metastasis matching the remote primary tumor. Results:Intrathyroid metastasis were detected in 24 patients. The intrathyroid metastases presented on 18F-PET/CT as focal nodular uptake (n = 21), multiple nodular uptake (n = 2), or diffuse uptake/infiltration of the thyroid gland (n = 1). The SUV ranged between 3.9 and 42 (median 12.5 ± 7.5); in 2 patients, the FDG-avidity was minimal. On 18F-PET/CT, distant metastases were present outside the neck (n = 18), or limited to the neck (n = 6). In 2 of these 6 patients, the thyroid was the only site of metastatic disease. Due to the metastatic disease, the therapy was changed in 23 of 24 patients; 1 patient was lost to follow-up. Conclusion:In any patient with a previous or current history of an extrathyroid malignancy, an 18FDG-avid thyroid mass or diffuse infiltration of the thyroid on 18F-PET/CT should be considered a potential intrathyoid metastasis until proven otherwise. Knowledge of an intrathyroid metastasis may impact patient management, especially if the thyroid or neck are the only sites of metastatic disease.
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Project description:BackgroundNon-Hodgkin lymphoma (NHL) comprises biologically and clinically heterogeneous subtypes. Previously, study size has limited the ability to compare and contrast the risk factor profiles among these heterogeneous subtypes.MethodsWe pooled individual-level data from 17 471 NHL cases and 23 096 controls in 20 case-control studies from the International Lymphoma Epidemiology Consortium (InterLymph). We estimated the associations, measured as odds ratios, between each of 11 NHL subtypes and self-reported medical history, family history of hematologic malignancy, lifestyle factors, and occupation. We then assessed the heterogeneity of associations by evaluating the variability (Q value) of the estimated odds ratios for a given exposure among subtypes. Finally, we organized the subtypes into a hierarchical tree to identify groups that had similar risk factor profiles. Statistical significance of tree partitions was estimated by permutation-based P values (P NODE).ResultsRisks differed statistically significantly among NHL subtypes for medical history factors (autoimmune diseases, hepatitis C virus seropositivity, eczema, and blood transfusion), family history of leukemia and multiple myeloma, alcohol consumption, cigarette smoking, and certain occupations, whereas generally homogeneous risks among subtypes were observed for family history of NHL, recreational sun exposure, hay fever, allergy, and socioeconomic status. Overall, the greatest difference in risk factors occurred between T-cell and B-cell lymphomas (P NODE < 1.0×10(-4)), with increased risks generally restricted to T-cell lymphomas for eczema, T-cell-activating autoimmune diseases, family history of multiple myeloma, and occupation as a painter. We further observed substantial heterogeneity among B-cell lymphomas (P NODE < 1.0×10(-4)). Increased risks for B-cell-activating autoimmune disease and hepatitis C virus seropositivity and decreased risks for alcohol consumption and occupation as a teacher generally were restricted to marginal zone lymphoma, Burkitt/Burkitt-like lymphoma/leukemia, diffuse large B-cell lymphoma, and/or lymphoplasmacytic lymphoma/Waldenström macroglobulinemia.ConclusionsUsing a novel approach to investigate etiologic heterogeneity among NHL subtypes, we identified risk factors that were common among subtypes as well as risk factors that appeared to be distinct among individual or a few subtypes, suggesting both subtype-specific and shared underlying mechanisms. Further research is needed to test putative mechanisms, investigate other risk factors (eg, other infections, environmental exposures, and diet), and evaluate potential joint effects with genetic susceptibility.
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Project description:Classical Hodgkin lymphoma (cHL) is characterized by nearly universal genetic alterations in 9p24.1, resulting in constitutive expression of PD-1 ligands. This likely underlies the unique sensitivity of cHL to PD-1 blockade, with response rates of ?70% in relapsed/refractory disease. There are now numerous clinical trials testing PD-1 inhibitors in earlier stages of treatment and in combination with many other therapies. In general, non-Hodgkin lymphomas (NHLs) do not display a high frequency of 9p24.1 alterations and do not share cHL's vulnerability to PD-1 blockade. However, a few entities have genetic or immunologic features that may predict sensitivity to immune checkpoint blockade. These include primary mediastinal B cell lymphoma, primary central nervous system lymphoma, and primary testicular lymphoma, which harbor frequent alterations in 9p24.1, as well as Epstein Barr virus (EBV)-infected lymphomas, where EBV infection leads to increased PD-L1 expression. Although these subtypes may be specifically vulnerable to PD-1 blockade, the majority of NHLs appear to be minimally sensitive to PD-1 blockade monotherapy. Current investigations in NHL are therefore focusing on targeting other checkpoints or studying PD-1-based combination therapy. Looking forward, additional insight into the most common mechanisms of resistance to immune checkpoint inhibitors will be important to guide rational clinical trial design. In this review, we describe the biological basis for checkpoint blockade in cHL and NHL and summarize the clinical data generated to date. Guided by our rapidly evolving understanding of the pathobiology of various lymphoma subtypes, we are hopeful that the role of checkpoint inhibitors in lymphoma treatment will continue to grow.
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Project description:BACKGROUND:In order to study the CXCR4 expression with [68Ga]pentixafor PET in different types of non-Hodgkin lymphoma, we performed a retrospective study to describe the [68Ga]pentixafor PET/CT imaging in a spectrum of lymphomas and to compare it with [18F]FDG PET/CT. RESULTS:Twenty-seven patients with newly diagnosed non-Hodgkin lymphoma were recruited retrospectively. [68Ga]pentixafor PET showed increased radioactivity in lymphoplasmacytic lymphoma (n = 8), marginal zone lymphoma (n = 4), diffuse large B cell lymphoma (n = 3), follicular lymphoma (n = 2), mantle cell lymphoma (n = 1), unclassified indolent B cell lymphoma (n = 3), and enteropathy associated T cell lymphoma (n = 3). However, peripheral T cell lymphoma, not otherwise specified (n = 1), and NK/T cell lymphoma (n = 2) were not avid for [68Ga]pentixafor. In comparison to [18F]FDG PET, [68Ga]pentixafor PET demonstrated more extensive disease and higher radioactivity in lymphoplasmacytic lymphoma and marginal zone lymphoma. CONCLUSION:CXCR4 expression varies in different types of non-Hodgkin lymphoma. Overexpression of CXCR4 was detected with [68Ga]pentixafor PET/CT in lymphoplasmacytic lymphoma, marginal zone lymphoma, diffuse large B cell lymphoma, follicular lymphoma, mantle cell lymphoma, unclassified indolent B cell lymphoma, and enteropathy associated T cell lymphoma. The uptake of [68Ga]pentixafor was higher than [18F]FDG in lymphoplasmacytic lymphoma and marginal zone lymphoma.
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