Differences in the imaging features and distribution of non-indolent and indolent mastocytosis: a single institution experience of 29 patients.

PURPOSE: Compare imaging features of indolent and non-indolent mastocytosis. METHODS: For 29 patients, imaging features, imaging indications, and distribution of indolent and non-indolent mastocytosis subtypes were analyzed. RESULTS: 16/29 (55%) patients had three distinct patterns of osseous abnormality, not significantly differing between cohorts. Non-indolent disease was more likely to present with hepatomegaly (p=0.0004), splenomegaly (p=0.0097), and lymphadenopathy (p=0.0079). CT, was the most common initial imaging modality, ordered to stage disease in 20 of 29 patients (69%). CONCLUSION: Understanding patterns of involvement of indolent and nonindolent mastocytosis across modalities could assist radiologists in evaluating mastocytosis.

Diffuse Large B-Cell Lymphoma in the Era of Precision Oncology: How Imaging Is Helpful.

Diffuse large B cell lymphoma (DLBCL) is the most common histological subtype of Non-Hodgkin's lymphoma. As treatments continues to evolve, so do imaging strategies, and positron emission tomography (PET) has emerged as the most important imaging tool to guide oncologists in the diagnosis, staging, response assessment, relapse/recurrence detection,and therapeutic decision making of DLBCL. Other imaging modalities including magnetic resonance imaging (MRI), computed tomography (CT), ultrasound, and conventional radiography are also used in the evaluation of lymphoma. MRI is useful for nervous system and musculoskeletal system involvement and is emerging as a radiation free alternative to PET/CT. This article provides a comprehensive review of both the functional and morphological imaging modalities, available in the management of DLBCL.

Metastatic Patterns of Solitary Fibrous Tumors: A Single-Institution Experience.

OBJECTIVE: The objective of our study was to evaluate the metastatic patterns and imaging features of solitary fibrous tumors (SFTs). MATERIALS AND METHODS: This retrospective study included 139 patients with pathologically proven SFT, 49 of whom developed metastases. Electronic medical records and all available images were reviewed to record the pattern and imaging appearances of metastatic disease, and comparisons of thoracic SFTs and extrathoracic SFTs were also performed. Associations of metastatic spread were studied using univariate and multivariate Cox regression analyses. RESULTS: A total of 49 (35%) patients developed metastases at a median of 124 months (interquartile range [IQR], 66-195 months) after SFT diagnosis; 11 patients (8%) had metastases at presentation. Of these 49 patients, 40 patients died at a mean of 183 months after diagnosis. The associations with metastatic disease on univariate analysis were tumor size ≥ 10 cm (p = 0.01) and malignant pathology or mitotic count ≥ 4 per 10 high-power fields (HPF) (p < 0.001). Malignant pathology and a mitotic count of ≥ 4 per 10 HPF were also associated with metastatic disease on multivariate analysis (p = 0.01; hazard ratio, 0.22; 95% CI, 0.05-0.73). The most common sites of metastasis were the lungs (30/49, 61%) followed by the pleura (24/49, 49%) and then the liver (20/49, 41%), bones (20/49, 41%), and peritoneum (20/49, 41%). A significantly higher proportion of patients with extrathoracic SFT had metastatic disease (37/139, 27%) compared with those with thoracic SFT (12/139, 9%) (p = 0.003). The overall metastasis-free survival was a median of 117 months (IQR, 33-169 months) in patients with extrathoracic SFT and a median of 120 months (IQR, 82-169 months) in patients with thoracic SFT (p = 0.01). CONCLUSION: A mitotic count of ≥ 4 per 10 HPF or malignant pathology was significantly associated with metastatic disease on both univariate and multivariate analyses. The sites of metastatic disease differed depending on the site of the primary SFT but were most commonly the lung and pleura. Patients with extrathoracic SFT were statistically more likely to develop metastatic disease than those with thoracic SFT.

Current Concepts in the Molecular Genetics and Management of Thyroid Cancer: An Update for Radiologists.

Substantial improvement in the understanding of the oncogenic pathways in thyroid cancer has led to identification of specific molecular alterations, including mutations of BRAF and RET in papillary thyroid cancer, mutation of RAS and rearrangement of PPARG in follicular thyroid cancer, mutation of RET in medullary thyroid cancer, and mutations of TP53 and in the phosphatidylinositol 3'-kinase (PI3K)/AKT1 pathway in anaplastic thyroid cancer. Ultrasonography (US) and US-guided biopsy remain cornerstones in the initial workup of thyroid cancer. Surgery is the mainstay of treatment, with radioactive iodine (RAI) therapy reserved for differentiated subtypes. Posttreatment surveillance of thyroid cancer is done with US of the thyroid bed as well as monitoring of tumor markers such as serum thyroglobulin and serum calcitonin. Computed tomography (CT), magnetic resonance imaging, and fluorine 18 fluorodeoxyglucose positron emission tomography/CT are used in the follow-up of patients with negative iodine 131 imaging and elevated tumor markers. Certain mutations, such as mutations of BRAF in papillary thyroid carcinoma and mutations in RET codons 883, 918, and 928, are associated with an aggressive course in medullary thyroid carcinoma, and affected patients need close surveillance. Treatment options for metastatic RAI-refractory thyroid cancer are limited. Currently, Food and Drug Administration-approved molecularly targeted therapies for metastatic RAI-refractory thyroid cancer, including sorafenib, lenvatinib, vandetanib, and cabozantinib, target the vascular endothelial growth factor receptor and RET kinases. Imaging plays an important role in assessment of response to these therapies, which can be atypical owing to antiangiogenic effects. A wide spectrum of toxic effects is associated with the molecularly targeted therapies used in thyroid cancer and can be detected at restaging scans. (©)RSNA, 2016.

MRI Findings in Patients With Leukemia and Positive CSF Cytology: A Single-Institution 5-Year Experience.

OBJECTIVE: The purposes of this study were to describe the spectrum of MRI findings and determine the prognostic role of MRI in adults with acute leukemia with positive CSF cytology. MATERIALS AND METHODS: In this retrospective study of 34 patients (19 women, 15 men; mean age, 51 years; range, 18-72 years) treated for CNS leukemia between 2006 and 2011, 31 (91%) contrast-enhanced brain and 14 (41%) spine MRI studies were reviewed by two radiologists to note patterns of enhancement. Interobserver agreement and correlation of enhancement with outcome were analyzed. RESULTS: MRI showed abnormal findings in 25 patients (74%). Pachymeningeal enhancement (n = 9/31, 29%), leptomeningeal enhancement (n = 6/31, 19%), cranial nerve enhancement (n = 9/31, 29%), masslike enhancement (n = 3/31, 10%), and spinal meningeal enhancement (n = 10/14, 71%) were identified. There was strong interobserver agreement (κ = 0.906). Survival rates were shorter to a statistically significant degree with pachymeningeal enhancement (median, 7 months; interquartile range [IQR], 5-8 months versus median, 26 months; IQR, 15 months to not reached; p = 0.004) and two or more sites of enhancement (median, 8 months; IQR, 3-13 months versus median, 19 months; IQR, 9 months to not reached; p = 0.046). CONCLUSION: Brain or spine MRI examinations (or both) showed abnormal findings in nearly three-fourths of adults with acute leukemia with positive CSF cytology who were imaged for neurologic symptoms. Pachymeningeal enhancement and two or more sites of brain involvement were associated with shorter survival.

Role of Imaging in Management of Desmoid-type Fibromatosis: A Primer for Radiologists.

Desmoid-type fibromatosis (DF) is a locally aggressive fibroblastic neoplasm that has variable clinical and biologic behaviors ranging from indolent tumors that can undergo spontaneous regression to aggressive tumors with a tendency toward local invasion and recurrence. The management of DF has evolved considerably in the last decade from aggressive first-line surgery and radiation therapy to systemic treatment (chemotherapy, hormonal therapy, and targeted therapy) and symptomatic local control (surgery and radiation therapy). Imaging plays an important role in each of these treatment settings. In surgical candidates, computed tomography (CT) and magnetic resonance (MR) imaging are the modalities of choice for assessing resectability and surgical planning. For evaluating recurrence, MR imaging is the modality of choice for extra-abdominal recurrence, whereas CT is the preferred modality for intra-abdominal recurrence. Signal intensity changes at MR imaging can be used to monitor the biologic behavior of certain DFs chosen for expectant management. Response to systemic treatment with anti-inflammatory agents, hormonal therapy (eg, tamoxifen), cytotoxic chemotherapy (eg, doxorubicin, vinblastine, methotrexate), and targeted therapy (eg, sorafenib), as well as to radiation therapy, can be assessed at CT by monitoring size and attenuation changes or at MR imaging by monitoring size, T2 signal intensity, and degree of enhancement. Several patterns of response can be seen at imaging. Imaging also helps in detecting complications associated with systemic therapy and radiation therapy. (©)RSNA, 2016.

Recent developments in the use of computed tomography scanners in coronary artery imaging.

INTRODUCTION: Within the past decade, substantial evolution of Coronary CT Angiography (CCTA) has affected evaluation and management of coronary artery disease. In particular, technical advancement of hardware technology and image reconstruction of CT scanners have played an important role in this context making it possible to acquire abundant data with excellent temporal and spatial resolution within a shorter scan time. In addition, a concern related to the high radiation exposure in the initial noninvasive coronary artery imaging has triggered improvement in dose reduction techniques. AREAS COVERED: In this review article, we have focused on recent technological developments in CT scanners and the impact of these developments on CCTA parameters. Expert Commentary: CCTA plays an important role in coronary artery disease management, and technical development of the CT scanners can be expected to address and remedy technical limitations.

Solitary Fibrous Tumors: 2016 Imaging Update.

Optimal management of solitary fibrous tumor requires a multidisciplinary approach with proper histopathological mapping and use of various imaging modalities for exact delineation of primary tumor and metastatic disease if present. In this article, the authors present a comprehensive review of the spectrum of imaging findings of solitary fibrous tumors involving various organ systems and discuss the role of molecular targeted therapies in the management of metastatic disease.

Thrombus in hypoplastic aorta: An uncommon cause of acute myocardial infarction.

A coronary artery embolism is an uncommon non-atherosclerotic cause of acute myocardial infarction. We present a case of coronary artery embolism in a patient with past history of hypoplastic left heart syndrome that was initially palliated via a modified Blalock-Taussig shunt followed by a Fontan anastomosis and Damus-Kaye-Stansel type anastomosis of the pulmonary valve to the ascending hypoplastic aorta. In this case we demonstrate usefulness of cardiac CT to delineate the patient's complex anatomy, identify the presence and etiology of a thromboembolic event, as well as assess for appropriate response to anticoagulation therapy.

Soft-Tissue Sarcomas: An Update for Radiologists Based on the Revised 2013 World Health Organization Classification.

OBJECTIVE: Soft-tissue sarcomas are a diverse group of malignancies, and our rapidly improving understanding of their molecular pathogenesis and treatment is leading to better clinical outcomes. The revised 2013 World Health Organization (WHO) classification of soft-tissue sarcomas introduced several important changes. We provide a comprehensive overview of the relevant changes for radiologists. CONCLUSION: Rapid advances in the understanding of the pathogenesis and molecular biology of soft-tissue sarcomas led to major revisions in the 2013 WHO classification. To provide optimal multidisciplinary patient care, radiologists must remain up-to-date with the latest developments in the field of soft-tissue sarcomas to best correlate the histologic and imaging features of the various types of tumors and understand the unique patterns of treatment response and disease recurrence.

Update on the imaging of malignant perivascular epithelioid cell tumors (PEComas).

Malignant perivascular epithelioid cell tumors (PEComas) are a histologic group of mesenchymal neoplasms that share a distinctive histological phenotype, the perivascular epithelioid cell. These tumors are known for their perivascular distribution. Malignant PEComas have a female predominance and are associated with aggressive disease and poor prognosis, making timely diagnosis critical to management. Imaging features of malignant PEComas are nonspecific and mimic other benign and malignant neoplasms. Surgery is the mainstay in the management of malignant PEComas. Promising novel molecular targeted therapies like m-TOR inhibitors have been shown to be effective in the metastatic setting. The aim of this review is to familiarize radiologists with the imaging appearances of and potential therapies for primary and metastatic malignant PEComa.

Multimodality imaging of osseous involvement In haematological malignancies.

The purpose of this article is to provide a comprehensive review of the imaging features of osseous involvement in haematological malignancies. Osseous involvement can be seen in various haematological malignancies including lymphomas, plasma cell neoplasms, leukaemias and myeloproliferative neoplasms. Imaging plays a crucial role in initial diagnosis, staging and in the assessment of treatment response in these patients.

Systemic treatment in breast cancer: a primer for radiologists.

UNLABELLED: Cytotoxic chemotherapy, hormonal therapy and molecular targeted therapy are the three major classes of drugs used to treat breast cancer. Imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI), (18)F-FDG positron emission tomography (PET)/CT and bone scintigraphy each have a distinct role in monitoring response and detecting drug toxicities associated with these treatments. The purpose of this article is to elucidate the various systemic therapies used in breast cancer, with an emphasis on the role of imaging in assessing treatment response and detecting treatment-related toxicities. TEACHING POINTS: • Cytotoxic chemotherapy is often used in combination with HER2-targeted and endocrine therapies. • Endocrine and HER2-targeted therapies are recommended in hormone-receptor- and HER2-positive cases. • CT is the workhorse for assessment of treatment response in breast cancer metastases. • Alternate treatment response criteria can help in interpreting pseudoprogression in metastasis. • Unique toxicities are associated with cytotoxic chemotherapy and with endocrine and HER2-targeted therapies.

Cardiac metastasis from renal cell carcinoma in cardiac CT.

Cardiac metastases from RCC in the absence of transvenous spread are rare. We present a case of cardiac metastases from RCC demonstrating usefulness of cardiac CT in planning surgical management, which provides superior spatial resolution for evaluation of relationship between the tumor and coronary arteries.

Imaging of Fluid in Cancer Patients Treated With Systemic Therapy: Chemotherapy, Molecular Targeted Therapy, and Hematopoietic Stem Cell Transplantation.

OBJECTIVE: The purpose of this article is to provide a comprehensive review of the imaging features of various systemic treatment-related causes of fluid accumulation in cancer patients. CONCLUSION: Systemic treatment-related fluid accumulation can occur with chemotherapy, molecular targeted therapy, or hematopoietic stem cell transplantation. Imaging findings such as new ascites, pleural and pericardial effusions, and subcutaneous edema should be interpreted with caution on restaging studies.

Extracutaneous melanomas: a primer for the radiologist.

OBJECTIVE: The purpose of this article is to provide a comprehensive review of the imaging features of extracutaneous melanomas. CONCLUSION: Extracutaneous melanomas are clinically and biologically distinct from their more common cutaneous counterpart with higher frequency of metastatic disease and poorer overall prognosis. Complete surgical excision is the treatment of choice whenever possible; systemic therapy in the form of conventional chemotherapeutic agents as well as novel targeted agents is used for advanced/ metastatic disease. Multiple imaging modalities including US, CT, MRI and FDG-PET/CT play important roles in the evaluation of the primary tumour, assessment of metastatic disease and monitoring response to treatment. Radiologists should be aware of the typical imaging manifestations of extracutaneous melanoma, the distinct patterns of metastatic involvement as well as treatment response and toxicities associated with newer molecular targeted and immunotherapies to optimally contribute to patient management. TEACHING POINTS: • Mucosal melanoma is clinically and biologically distinct from cutaneous melanoma. • Mucosal melanoma has a higher rate of metastatic disease than the cutaneous subtype. • Imaging is helpful in assessment of disease and response to treatment.

Imaging of Nervous System Involvement in Hematologic Malignancies: What Radiologists Need to Know.

OBJECTIVE: The purpose of this article is to provide a comprehensive review of the imaging features of neurologic involvement in hematologic malignancies. CONCLUSION: Neurologic involvement can be seen in lymphoma, leukemia, post-transplant lymphoproliferative disorder (PTLD), plasma cell neoplasms, and histiocytic and dendritic neoplasms. Imaging, MRI in particular, plays an important role in the workup of these patients. Familiarity with the imaging features of nervous system involvement in hematologic malignancies can help radiologists suggest the diagnosis and guide management.

Beyond PET/CT in Hodgkin lymphoma: a comprehensive review of the role of imaging at initial presentation, during follow-up and for assessment of treatment-related complications.

OBJECTIVE: The purpose of this article is to provide a comprehensive review of the role of imaging modalities other than PET/CT in the management of Hodgkin lymphoma (HL). PET/CT is the imaging modality of choice in the management of Hodgkin's lymphoma (HL). However, imaging modalities other than PET/CT such as plain radiographs, ultrasound, CT, MRI and nuclear imaging can help in various stages of clinical management of HL, including the initial workup and post-treatment surveillance. Both CT and MRI help in detecting recurrences, treatment-related pulmonary, cardiovascular and abdominal complications as well as second malignancies. Familiarity with expected post-treatment changes and complications on surveillance images can help radiologists guide patient management. The purpose of this article is to provide a comprehensive review of the role of imaging modalities other than PET/CT in the management of Hodgkin lymphoma (HL). MAIN MESSAGES: • Surveillance of HL patients is usually performed with plain radiographs and CT. • Follow-up imaging can depict normal post-treatment changes or treatment-related complications. • Imaging is important for the timely detection of second malignancies in HL patients.