Disease Characteristics, Radiologic Patterns, Comorbid Diseases, and Ethnic Differences in 32 Patients With Rosai-Dorfman Disease.

OBJECTIVE: Rosai-Dorfman disease (RDD) is a rare and idiopathic nonneoplastic disease of histiocytes that is characterized by lymphadenopathy and extranodal disease. In this study, we documented anatomical preferences, imaging findings, comorbid diseases, and ethnic differences in 32 RDD patients. METHODS: We conducted a retrospective review of pathologically confirmed cases seen at our institution from 1998 to 2016. These cases were analyzed for (a) anatomical locations, (b) radiologic appearance, (c) comorbid diseases, and (d) differences between ethnic groups. RESULTS: We found 32 patients with RDD, 18 were women and 14 were men. There were 51 lesions in all patients, 23.5% of which were nodal, involving 11 lymph node regions, and 76.5% were extranodal. Cervical lymph nodes and maxillofacial area were the most common affected nodal and extranodal locations, respectively. Only 4 (12.5%) of 32 patients had pure nodal involvement, whereas 20 (62.5%) of 32 had pure extranodal disease and 8 (25%) of 32 had mixed nodal and extranodal disease.Anatomically, RDD affected multiple organs in our cohort, including the lymphatic system, maxillofacial area (glandular and nonglandular tissues), superficial soft tissue, central nervous system, breast, peritoneum, gastrointestinal tract, and lungs.Radiologically, RDD presentation was variable from an organ to another. However, most lesions were hypermetabolic on 18F-fluorodeoxyglucose positron-emission tomography/computed tomography and isointense on T1-weighted magnetic resonance imaging. Computed tomographic findings were extremely variable between organs.Comorbid diseases were found in 11 patients. Those patients had 17 comorbid diseases; the most common were autoimmune diseases, viral diseases, and cancer.The organ distribution of RDD was slightly different between ethnic groups. The most frequent disease location for African Americans was lymph nodes; for whites, central nervous system and nonglandular maxillofacial (27.3% each); for Asians, lymph nodes, subcutaneous tissue, and nonglandular maxillofacial (25% each); and for Hispanics, lymph nodes and glandular maxillofacial (33.3% each). CONCLUSIONS: Rosai-Dorfman disease represents a wide-spectrum disease not limited to lymph nodes. Radiologically, RDD has diverse imaging findings. However, most lesions were hypermetabolic on 18F-fluorodeoxyglucose positron-emission tomography/computed tomography and isointense on T1-weighted imaging. Patients with RDD have a high rate of comorbid diseases including autoimmune disease, viral infections, and cancer.

VIDEO: Preoperative CT Angiography for Scapula Osteocutaneous Free Flap Reconstructions.

OBJECTIVE. The objective of this video article is to discuss the use of the scapular osteocutaneous free flap in reconstructive procedures. We attempt to discuss normal and variant vascular anatomy, image acquisition via CT angiography, and image interpretation as well as computer-assisted design and manufacturing. CONCLUSION. The scapular osteocutaneous free flap is commonly used for maxillary and mandibular reconstructive surgery. The complex vasculature supplying the scapular region allows flap versatility. There are anatomic variations in the origin of the circumflex scapular and angular arteries. Our method of performing and reporting CT angiography for patients scheduled to undergo scapular osteocutaneous free flap procedures provides a reliable and reproducible means of communicating important elements of vasculature to surgeons. This in turn can facilitate the manufacturing of custom scapular cutting guides and improve surgical outcomes.

Calcified leiomyoma of the deltoid: pathophysiology and imaging review.

Leiomyomas are benign tumors of smooth muscle cells. Leiomyomas of somatic soft tissue are a specific class of leiomyoma believed to arise from the smooth muscle cells found in the walls of blood vessels and represent less than 4% of benign, somatic soft tissue tumors. Of the somatic soft tissue tumors, approximately one-third will become calcified. We report an intramuscular, calcified leiomyoma arising from the left deltoid of a 47-year-old Caucasian male. To the best of the authors' knowledge, this is the first reported case of a calcified, intramuscular leiomyoma of the deltoid. Imaging studies and patient presentation were initially suggestive of tumoral calcinosis or myositis ossificans. It was not until pathologic examination that the correct diagnosis of the calcified leiomyoma was made. Leiomyoma should be included in the differential diagnosis of calcified soft tissue masses. If excised with adequate margins, recurrence is unlikely.

The effects of granulocyte colony-stimulating factor on MR images of bone marrow.

Granulocyte colony-stimulating factor (G-CSF) analogs such as filgrastim/pegfilgrastim are increasingly used to enhance neutrophilic recovery after chemotherapy. It is widely known that, physiologically, pegfilgrastim stimulates marrow mitotic activity and induces marrow reconversion from fatty to cellular. However, there is limited literature discussing the effects of pegfilgrastim on musculoskeletal magnetic resonance imaging, with the consensus that marrow reconversion secondary to pegfilgrastim therapy is easily confounded with a malignant process, especially in patients with a history of cancer. We attempt to discuss the expected changes and MRI findings after pegfilgrastim therapy through a summary of current literature. Additionally, we provide images from our own practice to support the previously established findings. G-CSF-stimulated reconversion can appear as patchy expansions of baseline hematopoietic marrow, but can also appear to be diffusely homogeneous, adding to its ambiguity. We conclude that using a baseline MRI, clinical information, and assessing sequential MRI changes in conjunction with pegfilgrastim therapy may aid the differentiation between benign and pathological change. We expand our discussion to include the effects of novel technologies, such as whole-body MRI, chemical shift imaging, and contrast agents in helping the distinction.

VIDEO: Preoperative CT Angiography for Fibular Free Flap Reconstructions.

OBJECTIVE: The objective of this video article is to provide an introduction to the use of fibular free flaps. Normal and variant vascular anatomy of the fibular free flap is discussed, as are imaging acquisition and CT angiography interpretation, computer-assisted design and manufacturing, and the limitations of the fibular free flap. CONCLUSION: The fibular free flap is commonly used for head and neck reconstructive surgery. Variation exists between individuals regarding the origin of the peroneal artery and the perforating arteries. Our method of performing CT angiography and reporting its findings for patients undergoing a fibular free flap procedure provides a reproducible means of identifying important elements of the vasculature and effectively communicating their locations to surgeons. Accurate communication can maximize the success of the flap harvesting and the preoperative manufacture of custom fibular cutting guides.

A randomized, non-comparative phase 2 study of neoadjuvant immune-checkpoint blockade in retroperitoneal dedifferentiated liposarcoma and extremity/truncal undifferentiated pleomorphic sarcoma.

Based on the demonstrated clinical activity of immune-checkpoint blockade (ICB) in advanced dedifferentiated liposarcoma (DDLPS) and undifferentiated pleomorphic sarcoma (UPS), we conducted a randomized, non-comparative phase 2 trial ( NCT03307616 ) of neoadjuvant nivolumab or nivolumab/ipilimumab in patients with resectable retroperitoneal DDLPS (n = 17) and extremity/truncal UPS (+ concurrent nivolumab/radiation therapy; n = 10). The primary end point of pathologic response (percent hyalinization) was a median of 8.8% in DDLPS and 89% in UPS. Secondary end points were the changes in immune infiltrate, radiographic response, 12- and 24-month relapse-free survival and overall survival. Lower densities of regulatory T cells before treatment were associated with a major pathologic response (hyalinization > 30%). Tumor infiltration by B cells was increased following neoadjuvant treatment and was associated with overall survival in DDLPS. B cell infiltration was associated with higher densities of regulatory T cells before treatment, which was lost upon ICB treatment. Our data demonstrate that neoadjuvant ICB is associated with complex immune changes within the tumor microenvironment in DDLPS and UPS and that neoadjuvant ICB with concurrent radiotherapy has significant efficacy in UPS.

Parosteal osteosarcoma of the temporal bone: Case report.

Parosteal osteosarcomas (POS) are well-differentiated low-grade malignant sarcomas that are located on the surface of the bone. POS of the temporal bone is exceptionally rare, with less than a hand full of cases present in modern literature. Here, we report a POS of the temporal bone found incidentally and with an uncharacteristic presentation. We also review the unique imaging and histopathological findings of this entity and discuss why developing a broad differential diagnosis and proceeding with early intervention are considered imperative in this disease.

Parosteal Osteosarcoma of the skull: Pathophysiological and imaging review.

Parosteal Osteosarcoma (POS) is a well-differentiated low-grade malignant sarcoma occurring at the bone surface. POS of the skull is exceedingly rare, with only 4 temporal bone cases reported in modern literature. This tumor may resemble a multitude of entities, hence identifying it is critical. This may be achieved through a combination of clinical, histopathological, and imaging diagnostic techniques. POS may recur locally or dedifferentiate, the latter having a worse prognosis. This review aims to update the reader regarding the management of the rare Parosteal Osteosarcoma located in the skull bone.

The lateral forearm flap versus traditional upper extremity flaps: A comparison of donor site morbidity and flap thickness.

INTRODUCTION: The lateral forearm flap (LFF) is a thin fasciocutaneous flap with a donor site that can be closed primarily. METHODS: A retrospective analysis of donor site morbidity and hand function was performed in patients who underwent a radial forearm flap (RFF), ulnar artery perforator flap (UAPF), or LFF. Flap thickness was evaluated radiographically in 50 control patients. RESULTS: Of 134 patients (lateral forearm flap: n = 49, RFF: n = 47, UAPF: n = 38), the LFF demonstrated significantly faster return to baseline hand grip strength (3 months vs. 12 months in RFF and UAPF; p < 0.001), had significantly fewer donor site complications (6.1% compared to 6.4% in RFF and 28.9% in UAPF; p = 0.003) and fewer sensory deficits (2.0% compared to 6.4% in RFF and 15.8% in UAPF sites; p = 0.013). The radiographic study confirmed the LFF to be the thinnest of all upper extremity flap options. CONCLUSIONS: The LFF is an excellent forearm-based flap option with thin, pliable tissue and low donor site morbidity.

Feasibility of half the recommended dose of IV contrast in DECT: image quality evaluation and diagnostic acceptability in cancer patients.

PURPOSE: To assess the quality of dual-energy computed tomography (DECT) images in patients receiving 50% of the recommended weight-based volume of iodinated intravenous contrast medium. METHODS: The study included cancer patients who previously underwent abdominal CT on a DECT scanner using a single source with the full recommended weight-based dose of Iohexol 350. Using the same scanner, the patients underwent a portovenous phase DECT scan following intravenous injection of half of the recommended weight-based dose. Monochromatic energy images were processed at 60 and 70kEv and compared to polychromatic 140kVp images. Three radiologists independently scored the images for overall diagnostic acceptability and image quality of solid organs and vasculature. Regions of interest were drawn on the portal vein, aorta, liver, and fat to calculate contrast to noise ratio (CNR) and signal to noise ratio (SNR). A multivariate ordinal generalized estimating equations model was used to assess image quality score. Pairwise comparisons were performed of the readers' scores, CNR, and SNR. Agreement with respect to quality score was calculated by using Fleiss's kappa value. RESULTS: Diagnostic acceptability was better for the SECT (120kVp) scans than for the 70 and 60kEv scans, and better for the 70 and 60kEv scans than for the 140kVp scans. Noise was subjectively rated as best on the 70kEv images. SNR of the liver was highest on 70kEv images. SNR of the liver on 70kEv images was significantly better than SECT images (p < 0.0001). Liver CNR was highest on SECT (120kVp) images. CONCLUSION: DECT with 50% reduction in the volume of intravenous contrast produces image quality comparable to that of SECT in cancer patients.

Myxoid Liposarcoma With Skeletal Metastases: Pathophysiology and Imaging Characteristics.

Liposarcoma is a commonly occurring soft tissue sarcoma that can be divided into 4 subtypes. Myxoid and round cell liposarcoma (MRCL) represent one of these subtypes and are classified together due to their shared chromosomal translocation. Histologic analysis of MRCL reveals a myxoid matrix with a delicate capillary network and dispersed lipoblasts. Varying degrees of round cell component are also observed, with greater amounts of round cells indicating a higher histologic grade and poorer prognosis. MRCL has a unique pattern of spread due to its initial tendency to spread to extrapulmonary sites. Additionally, skeletal metastases are frequently found in cases of MRCL. While various imaging techniques are used to visualize MRCL and metastases, magnetic resonance imaging is generally the preferred method. This article reviews the pathophysiology and imaging features of MRCL as well as the imaging characteristics, advantages, and drawbacks of multiple imaging modalities for visualizing bone metastases.

Multiple Myeloma: Role of Imaging in Diagnosis, Staging, and Treatment Response Assessment.

Multiple myeloma is a common hematologic malignancy of plasma cells. Differentiating multiple myeloma from the precursor stages of monoclonal gammopathy of undetermined significance and smoldering multiple myeloma is very important because the treatment approach is different for each. The diagnosis is mainly clinical, while the role of imaging is confined to the staging process, assessing response to therapy, and monitoring for disease progression. In this article, we examine the role of different imaging modalities in patients with multiple myeloma.

Dermatofibrosarcoma Protuberans: Pathological and Imaging Review.

Dermatofibrosarcoma protuberans (DFSP) is a rare, low-to-intermediate grade sarcoma that typically arises in the dermis and infiltrates subcutaneous tissue. Due to superficial appearance of DFSP, imaging techniques are not always utilized. However, they may be useful in large or atypical cases. The standard treatment for DFSP is excision of the lesion. In this article, we review the role of different imaging modalities in the assessment and management of DFSP.

PTEN Hamartoma Tumor Syndrome/Cowden Syndrome: Genomics, Oncogenesis, and Imaging Review for Associated Lesions and Malignancy.

PTEN hamartoma tumor syndrome/Cowden syndrome (CS) is a rare autosomal dominant syndrome containing a germline PTEN mutation that leads to the development of multisystem hamartomas and oncogenesis. Benign tumors such as Lhermitte-Duclos disease and malignant tumors involving the breast, thyroid, kidneys, and uterus are seen in CS. Radiologists have an integral role in the comanagement of CS patients. We present the associated imaging findings and imaging screening recommendations. Knowledge of the types of cancers commonly seen in CS and their imaging findings can aid in early tumor recognition during cancer screening to help ensure near-normal life spans in CS patients.

Imaging of Neuroendocrine Prostatic Carcinoma.

Neuroendocrine prostate cancer (NEPC) is an aggressive subtype of prostate cancer that typically has a high metastatic potential and poor prognosis in comparison to the adenocarcinoma subtype. Although it can arise de novo, NEPC much more commonly occurs as a mechanism of treatment resistance during therapy for conventional prostatic adenocarcinoma, the latter is also termed as castration-resistant prostate cancer (CRPC). The incidence of NEPC increases after hormonal therapy and they represent a challenge, both in the radiological and pathological diagnosis, as well as in the clinical management. This article provides a comprehensive imaging review of prostatic neuroendocrine tumors.

Desmoid fibromatosis following surgical resection of spinal meningioma.

A 42-year-old female patient with a history of cervicothoracic junction meningioma World Health Organization grade I, resected in early 2011, was admitted to the hospital with intractable headache and lower extremity weakness. Magnetic resonance imaging (MRI) showed an epidural mass compressing the spinal cord at the prior surgical site, which was interpreted as recurrent meningioma. Following surgical resection, histopathological analysis revealed desmoid fibromatosis (desmoid tumor). In retrospect, dynamic contrast-enhanced magnetic resonance imaging performed prior to surgery should have allowed for prospective exclusion of meningioma as the recurrent mass and suggested an alternative diagnosis such as post-traumatic desmoid fibromatosis or the need for biopsy to confirm diagnosis.

Primary Osteosarcoma of the Breast: Pathophysiology and Imaging Review.

Extraskeletal osteosarcoma are rare malignant mesenchymal neoplasms of soft tissues representing around 1% of all soft tissue. The exact mechanism of tumorigenesis of primary breast osteosarcoma is still unclear. However, most of the cases develop without a recognized etiologic factor. Primary osteosarcoma of the breast is often initially misdiagnosed as breast fibroadenoma. Different imaging modalities and pathology play important role in differentiating breast osteosarcoma from other benign and malignant lesions of the breast resulting in dramatic change in the management.

Imaging in pediatric ovarian tumors.

The spectrum of ovarian tumors in the pediatric population differs significantly from that in adults. Germ cell tumors are the predominant class of ovarian tumors in children, whereas epithelial tumors are the most common in adults. Ultrasonography is the modality of choice for the initial evaluation of pediatric ovarian tumors. Determining the diagnosis based on imaging may prove difficult, and combining the imaging findings with the clinical scenario is very helpful in reaching a differential diagnosis during clinical practice. We will discuss the spectrum of ovarian neoplasms in the pediatric population and describe their clinical, pathologic, and imaging characteristics. A few unique entities related to ovarian tumors, such as growing teratoma syndrome, anti-N-methyl-D-aspartate receptor encephalitis, and hereditary ovarian tumor syndromes, are also discussed. In addition, we will review several entities that may mimic ovarian neoplasms as well as their distinct imaging features.

Gadolinium-based Contrast Agents Improve Detection of Recurrent Soft-Tissue Sarcoma at MRI.

Purpose: To determine the diagnostic efficacy of gadolinium-based contrast agents for the detection of recurrent soft-tissue sarcoma compared with non-contrast-enhanced conventional MRI sequences. Materials and Methods: A retrospective study of patients with soft-tissue sarcomas who were imaged from January 2009 to December 2014 was performed. MRI studies from 69 patients (mean age, 61 years ± 15 [standard deviation], 45 men) with recurrent soft-tissue sarcoma and 63 age-, sex-, and tumor-matched controls with positive findings (nonrecurrence) were presented to six musculoskeletal radiologists at a tertiary cancer center in three image groupings. Group 1 consisted of precontrast T1-weighted and fat-suppressed T2-weighted images (no contrast agent). Group 2 consisted of precontrast and postcontrast fat-saturated T1-weighted images. Group 3 consisted of precontrast and fat-saturated postcontrast T1- and fat-suppressed T2-weighted images. Images within these three groups contained either recurrent soft-tissue sarcomas or positive postoperative findings (nonsarcoma). The presentation order of the first two image sets was reversed for half the readers. The readers were asked to classify presence of tumor on a five-point scale. The average score from the readers was used as consensus score for each case, and a case was considered positive if the average score was less than 3. Receiver operating characteristic (ROC) analysis was performed using the average score for each image set. Results: Assessment of the group 3 image set resulted in higher sensitivity (74%, 95% confidence interval [CI]: 62%, 83%) than the group 2 image set (64%, 95% CI: 51%, 75%), which was also more sensitive than the assessment of the group 1 images set (49%, 95% CI: 37%, 61%), with P = .02 for both. There was no significant difference in specificity between the three groups. The area under the ROC curve (AUC) for the assessment of group 1 was 0.78 (95% CI: 0.70, 0.86), which was significantly lower than that of group 2, 0.92 (95% CI: 0.87, 0.96) and group 3, 0.93 (95% CI: 0.88, 0.97), with P values of .0006 and < .0001, respectively. There was no difference between the AUCs of groups 2 and 3 (P = .58). Conclusion: Gadolinium-based contrast agents improved diagnostic performance in detection of recurrent soft-tissue sarcoma. Addition of fat-saturated T2-weighted images provided modest improvement in sensitivity.Keywords: Efficacy Studies, MR-Contrast Agent, Oncology, Soft Tissues/Skin© RSNA, 2020.

Hematologic malignancies of the gastrointestinal luminal tract.

Hematologic malignancies include several lymphoproliferative and myeloproliferative disorders, many of which are frequently encountered in current health care settings. These malignancies frequently affect the gastrointestinal (GI) tract, either by secondary extranodal or extramedullary extension to the GI tract, or as a primary process arising in the GI tract. In fact, the GI tract may represent the most common extranodal site of involvement in many of them, such as lymphoma. Furthermore, in the current era of improved cancer treatment and advanced transplant procedures with increased survival, it has been quite common to encounter GI involvement by these malignancies through the disease course. Post-transplant lymphoproliferative disorder following kidney transplantation, for example, very commonly involves the GI tract. Other conditions that can involve the GI tract include multiple myeloma, plasmacytoma, myeloid sarcoma, mastocytosis, and Castleman disease. Imaging diagnosis of these malignancies can be challenging, since they are much less common than primary GI cancers and both share many common imaging features as well. However, certain imaging features, particularly in combination with a matching clinical scenario, play a pivotal role in diagnosing these conditions and directing further evaluation. In this article, we review common and rare hematologic malignancies of the GI tract and discuss their pathophysiologic, clinical, and imaging features.