Clinical benefit of baseline imaging in Merkel cell carcinoma: Analysis of 584 patients.

BACKGROUND: Merkel cell carcinoma (MCC) guidelines derive from melanoma and do not recommend baseline cross-sectional imaging for most patients. However, MCC is more likely to have metastasized at diagnosis than melanoma. OBJECTIVE: To determine how often baseline imaging identifies clinically occult MCC in patients with newly diagnosed disease with and without palpable nodal involvement. METHODS: Analysis of 584 patients with MCC with a cutaneous primary tumor, baseline imaging, no evident distant metastases, and sufficient staging data. RESULTS: Among 492 patients with clinically uninvolved regional nodes, 13.2% had disease upstaged by imaging (8.9% in regional nodes, 4.3% in distant sites). Among 92 patients with clinically involved regional nodes, 10.8% had disease upstaged to distant metastatic disease. Large (>4 cm) and small (<1 cm) primary tumors were both frequently upstaged (29.4% and 7.8%, respectively). Patients who underwent positron emission tomography-computed tomography more often had disease upstaged (16.8% of 352), than those with computed tomography alone (6.9% of 231; P = .0006). LIMITATIONS: This was a retrospective study. CONCLUSIONS: In patients with clinically node-negative disease, baseline imaging showed occult metastatic MCC at a higher rate than reported for melanoma (13.2% vs <1%). Although imaging is already recommended for patients with clinically node-positive MCC, these data suggest that baseline imaging is also indicated for patients with clinically node-negative MCC because upstaging is frequent and markedly alters management and prognosis.

Imaging of Merkel Cell Carcinoma: What Imaging Experts Should Know.

Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neuroendocrine tumor with a higher mortality rate than melanoma. Approximately 40% of MCC patients have nodal or distant metastasis at initial presentation, and one-third of patients will develop distant metastatic disease over their clinical course. Although MCC is rare, its incidence has been steadily increasing. Furthermore, the immunogenicity of MCC and its diagnostic and therapeutic application have made MCC one of the most rapidly developing topics in dermatology and oncology. Owing to the aggressive and complex nature of MCC, a multidisciplinary approach is necessary for management of this tumor, including dermatologists, surgeons, radiation oncologists, medical oncologists, pathologists, radiologists, and nuclear medicine physicians. Imaging plays a crucial role in diagnosis, planning for surgery or radiation therapy, and assessment of treatment response and surveillance. However, MCC is still not well recognized among radiologists and nuclear medicine physicians, likely owing to its rarity. The purpose of this review is to raise awareness of MCC among imaging experts by describing the epidemiology, pathophysiology, and clinical features of MCC and current clinical management with a focus on the role of imaging. The authors highlight imaging findings characteristic of MCC, as well as the clinical significance of CT, MRI, sentinel lymph node mapping, fluorine 18 fluorodeoxyglucose PET/CT, and other nuclear medicine studies such as bone scintigraphy and somatostatin receptor scintigraphy. ©RSNA, 2019.

PET/CT in the Diagnosis and Workup of Sarcoidosis: Focus on Atypical Manifestations.

Sarcoidosis is a multisystem disease characterized by the formation of noncaseating granulomas. Lung and intrathoracic lymph nodes are classic sites of involvement; however, sarcoidosis can affect any site in the body. The clinical course is extremely variable, and the imaging features are diverse and dependent on the affected site, degree of inflammation, and treatment the patient receives. Atypical manifestations and imaging findings can make diagnosis and/or management challenging. In addition, assessment of treatment response can be difficult in the setting of chronic disease. Fluorine 18 fluorodeoxyglucose (FDG) PET/CT is sensitive for assessment of the inflammatory activity of sarcoidosis in any organ. Although FDG PET/CT is not included in the standard workup for sarcoidosis, there has been growing evidence that supports the value of this examination in guiding diagnosis and management. FDG PET/CT may be especially useful for assessing reversible granuloma, treatment response, disease extent, occult disease, and cardiac or osseous sarcoidosis, and determining the most suitable biopsy site. Capability to image the entire body during a single examination is advantageous in cases of systemic disease such as sarcoidosis. The authors review the use of FDG PET/CT, providing up-to-date evidence and describing various cases of sarcoidosis in which FDG PET/CT has an important role in diagnosis and/or management. They also discuss the usefulness of FDG PET/CT in cases of selective manifestations of sarcoidosis. ©RSNA, 2018.

Rapidly growing giant cell tumor of bone in a skeletally immature girl.

Giant cell tumor of bone (GCTB) in skeletally immature patients is rare, and little is known regarding how fast GCTB can grow. We report a case of a 10-year-old skeletally immature girl with pathologically proven GCTB with obvious growth plate invasion that showed surprisingly rapid growth over only 14 days. A radiograph of the left knee revealed well-circumscribed, geographic bone destruction at the distal metaphysis of the femur with a focal cortical defect, suggesting a pathologic fracture. No abnormal mineralization or periosteal reaction was seen. A CT without contrast and an MRI demonstrated a homogeneous lesion with cortical disruption posteriorly and laterally with a slight soft tissue extension. Biopsy showed numerous multinucleated giant cells and spindle-shaped mononuclear cells without any sign of malignancy, suggesting GCTB. However, rapid lesion enlargement and destruction of the surrounding cortex were noted 14 days after biopsy. Considering the amount of bone destruction, traditional treatment of curettage and bone cement would not suffice to sustain structural strength. In addition, considering the patient's age, the tumor location, and the aggressive course, a malignant tumor, especially a giant cell-rich osteosarcoma, could not be excluded. Therefore, en bloc resection, including the growth plate and prosthetic replacement, were performed. Confirmation of GCTB was made from a pathologic evaluation, and a breach to the growth plate was identified. Since very little inflammatory reaction, degenerative change, or aneurysmal, bone, cyst-like change was found, the growth plate invasion was confirmed as due to GCTB extension, not due to the preoperative biopsy.

MRI findings of the shoulder and hip joint in patients with polymyalgia rheumatica.

OBJECTIVES: The purpose of this study is to evaluate magnetic resonance imaging (MRI) findings of the shoulder and hip joint in patients with polymyalgia rheumatica (PMR). METHODS: MR images of a total of 25 PMR patients (23 shoulders and 6 hips), 43 rheumatoid arthritis (RA) patients (22 shoulders and 22 hips), and 50 control patients (25 shoulders and 25 hips) were examined. The following MRI findings were evaluated: In the shoulder, thickness and abnormalities of the supraspinatus tendon, effusion around the glenohumeral joint, subacromial-subdeltoid bursa, and the biceps tendon; In the hip, effusion around the acetabulofemoral joint, iliopsoas bursa, and trochanteric bursa. Periarticular soft-tissue edema and bone findings were also analyzed. RESULTS: The supraspinatus tendon was significantly thicker in PMR patients than in RA patients and control patients (p < 0.05). Severe rotator cuff tendinopathy was frequently observed in PMR patients (p = 0.002). The scores for the amount of effusions (joint, bursa, and tendon sheath in the shoulder and bursa in the hip) were much higher in PMR patients (p < 0.05). Periarticular soft tissue edema was detected more frequently in PMR patients than in RA patients and control patients (p < 0.05). CONCLUSIONS: Thick supraspinatus tendon, severe rotator cuff tendinopathy, effusion around the joints, and periarticular soft tissue edema can be good indicators for the diagnosis of PMR.

CT findings of gastric and intestinal anisakiasis.

PURPOSE: To illustrate the CT findings of gastrointestinal anisakiasis. SUBJECTS AND METHODS: The Institutional Review Board approving this retrospective study waived the requirement for informed consent. Review of our emergency department's clinical records from September 2008 to January 2012 identified 41 consecutive patients who were diagnosed with gastrointestinal anisakiasis. 20 patients were diagnosed with gastric anisakiasis with endoscopically proven Anisakis larvae, and 21 patients were diagnosed with intestinal anisakiasis with positive test results for anti-anisakidae antibody and the presence of intestinal lesions on CT. Two radiologists retrospectively assessed the CT findings. RESULTS: The mean time delay from raw fish ingestion to symptom onset was 5.2 h (range 0.5-24 h) in gastric anisakiasis and 39 h (range 12-120 h) in intestinal anisakiasis. Gastric anisakiasis showed marked submucosal edema of the gastric wall (20/20 patients, 100%), increased attenuation of adjacent fat (19/20, 95%), and ascites (14/20, 70%) on CT. Intestinal anisakiasis showed marked submucosal edema of the intestine (21/21 patients, 100%) without showing complete intraluminal occlusion, ascites (21/21, 100%), increased attenuation of adjacent fat (19/21, 90%), and fluid collection in the distal segment of the constricted small intestine (13/21, 62%) on CT. CONCLUSION: Severe submucosal edema with ascites is a characteristic finding of gastrointestinal anisakiasis when compared with other forms of gastroenteritis. When CT shows the typical findings of gastrointestinal anisakiasis, radiologists may suggest the possibility of clinically undiagnosed anisakiasis, especially in intestinal anisakiasis as the diagnosis is sometimes difficult due to the long interval between food intake and symptom onset.

Magnetic resonance imaging for extramammary Paget's disease: radiological and pathological correlations.

Extramammary Paget's disease (EMPD) is a rare cutaneous neoplasm that is thought to represent intraepithelial adenocarcinoma developing in an area rich in apocrine glands. Magnetic resonance imaging (MRI) findings for this disease are not well established. We report three cases of pathologically confirmed EMPD in which MRI was performed before surgery. The lesions were widespread in the epidermis and the dermis. Lesions were sharply well enhanced on gadolinium-enhanced T1-weighted imaging and appeared hyperintense on diffusion-weighted imaging in all cases. Areas with enhancement in depth corresponded well with the pathological lesion. In addition, different malignant legions were found on the same images from MRI in two cases, indicating potential associations with other malignancies. We describe the MRI findings and their pathological correlation. MRI could be useful for preoperative evaluation of disease spread and detection of associated malignancies.

Severity of pseudofilling defect in the left atrial appendage on cardiac computed tomography is a simple predictor of the degree of left atrial emptying dysfunction in patients with chronic atrial fibrillation.

OBJECTIVES: The purpose of our study was to investigate the clinical relevance of a pseudofilling defect in the left atrial appendage (LAA) detected on coronary computed tomography (CT) angiography (CCTA) as an indicator of impaired left atrial (LA) volumetric function in patients with chronic atrial fibrillation (CAF). METHODS: Forty-two patients with CAF underwent CCTA. Quantitative and visual measurements of contrast enhancement of the LAA were performed, and they were correlated with results of CT volumetric functional analysis of the LA. Four volumetric parameters representing LA function were measured: maximum (LAVmax) and minimum volumes of the LA (LAVmin) through the entire cardiac cycle; LA emptying volume (LAEV); and LA emptying fraction (LAEF). All volumetric parameters were standardized by body surface area to adjust for variation in LA size among patients. For quantitative measurement, the CT attenuation was measured at the LAA and the LA to calculate an LAA/LA attenuation ratio. For visual measurement, contrast enhancement of the LAA was categorized into 3 groups; no filling defect, mild-to-moderate pseudofilling defect, and severe pseudofilling defect group. The Spearman correlation coefficient and the Kruskal-Wallis test were used for statistical analysis. RESULTS: The LAA/LA ratio showed a strong positive correlation with LAEV (r = 0.52; P < 0.001) and LAEF (r = 0.69; P < 0.001). The LAEV in the no pseudofilling defect group and the mild-to-moderate and severe pseudofilling defect groups were 16.1 ± 8.4, 10.8 ± 3.1, and 6.7 ± 4.9 mL/m², respectively (P < 0.001). The LAEF in each group were 24.2 ± 13.8%, 12.0 ± 3.4%, and 6.9 ± 3.1%, respectively (P < 0.001). CONCLUSIONS: The severity of pseudofilling defect in the LAA on CCTA could predict the degree of LA emptying dysfunction in patients with CAF.

Testicular FDG Uptake on PET/CT in Patients with Lymphoma: Correlation with Age.

The purpose of this observational study was to investigate whether the standard uptake value (SUV) measurement has practical utility in distinguishing secondary testicular involvement from physiologic uptake in patients with lymphoma. A Radiology Information System (RIS) search was conducted for all PET/CT studies performed from 2010-2016 on adult male patients with a diagnosis of lymphoma. Patients with clinical or pathologic diagnosis of testicular lymphoma were excluded to undergo a separate analysis. PET/CT images of 606 patients with 1087 scans, in which 2045 testes were included in the field of view, were reviewed and measurements were performed for standardized uptake values of both testicles (SUVmax) as well as of the liver (SUVmax and SUVmean). The mean SUVmax of the testicles was 3.75 ± 0.90 (range 1.16-8.38). The mean ratio of testis SUVmax / liver SUVmean (T/L) was 1.78 ± 0.43. Trends in SUVmax and age were significant for a negative correlation by a small magnitude of 0.066 per 10 years (P < 0.001). T/L had similar changes with significant low magnitude decrease with increasing age (0.059 per 10-year increase, P < 0.001). In our separate analysis of 3 patients with clinical or pathology proven testicular lymphoma, the average pathologic SUVmax was 13.47 (range 11.39-15.97). This study has the largest known sample size for quantifying physiologic uptake in the testes. SUV measurements to quantify F-18 Fluorodeoxyglucose (FDG) uptake on PET/CT likely have practical utility in discriminating between physiologic and pathologic uptake of FDG in cases of secondary testicular lymphoma.

Management and Prognosis of Cardiac Metastatic Merkel Cell Carcinoma: A Case-Control Study and Literature Review.

Merkel cell carcinoma (MCC), an aggressive neuroendocrine skin cancer, has a high rate (20%) of distant metastasis. Within a prospective registry of 582 patients with metastatic MCC (mMCC) diagnosed between 2003-2021, we identified 9 (1.5%) patients who developed cardiac metastatic MCC (mMCC). We compared overall survival (OS) between patients with cardiac and non-cardiac metastases in a matched case-control study. Cardiac metastasis was a late event (median 925 days from initial MCC diagnosis). The right heart was predominantly involved (8 of 9; 89%). Among 7 patients treated with immunotherapy, 6 achieved a complete or partial response of the cardiac lesion. Among these 6 responders, 5 received concurrent cardiac radiotherapy (median 20 Gray) with immunotherapy; 4 of 5 did not have local disease progression or recurrence in the treated cardiac lesion. One-year OS was 44%, which was not significantly different from non-cardiac mMCC patients (45%, p = 0.96). Though it occurs relatively late in the disease course, cardiac mMCC responded to immunotherapy and/or radiotherapy and was not associated with worse prognosis compared to mMCC at other anatomic sites. These results are timely as cardiac mMCC may be increasingly encountered in the era of immunotherapy as patients with metastatic MCC live longer.

Primary Intra-abdominal Ewing's Sarcoma in Adults: A Multimodality Imaging Spectrum.

Ewing sarcoma (ES) and peripheral primitive neuroectodermal tumor are part of a spectrum of neoplastic diseases known as the ES family of tumors, which also includes extraosseous ES, peripheral primitive neuroectodermal tumor, malignant small-cell tumor of the thoracopulmonary region (Askin's tumor), and atypical ES. Although imaging features of these tumors have been previously described, extensive discussion about intra-abdominal manifestations is scarce in the literature. We present an imaging spectrum of these tumors in the abdomen and pelvis with particular attention to multimodality approach for staging and restaging.

Lacrimal gland uptake on F-18 florbetapir amyloid positron emission tomography scan.

In 2012, the Food and Drug Administration (FDA) approved the use of F-18 florbetapir to estimate ß-amyloid neuritic plaque density when indicated. A normal scan will show increased radiotracer uptake in the white matter. Mild uptake in salivary glands, skin, muscles, and bones is considered normal. Being a new and infrequently performed study, familiarity with normal biodistribution and variants is important. We hereby present 2 cases with F-18 florbetapir uptake in lacrimal glands. Patients had no symptoms or known systemic conditions to explain this uptake. We speculate that lacrimal gland uptake of F-18 florbetapir could represent a normal variant.

Morphological and clinical risk factors for posterior communicating artery aneurysm rupture.

OBJECT: Recent studies have shown that posterior circulation aneurysms, specifically posterior communicating artery (PCoA) aneurysms, are more likely to rupture than other aneurysms. To date, few studies have investigated the factors contributing to PCoA aneurysm rupture. The authors aimed to identify morphological and clinical characteristics predisposing to PCoA aneurysm rupture. METHODS: The authors retrospectively reviewed 134 consecutive patients with PCoA aneurysms managed at their facility between July 2003 and December 2012. The authors divided patients into groups of those with aneurysmal rupture (n = 39) and without aneurysmal rupture (n = 95) and compared morphological and clinical characteristics. Morphological characteristics were mainly evaluated by 3D CT angiography and included diameter of arteries (anterior cerebral artery, middle cerebral artery, and internal carotid artery), size of the aneurysm, dome-to-neck ratio, neck direction of the aneurysmal dome around the PCoA (medial, lateral, superior, inferior, and posterior), aneurysm bleb formation, whether the PCoA was fetal type, and the existence of other intracranial unruptured aneurysm(s). RESULTS: Patients with ruptured PCoA aneurysms were significantly younger (a higher proportion were < 60 years of age) and a significantly higher proportion of patients with ruptured PCoA aneurysms showed a lateral direction of the aneurysmal dome around the PCoA, had bleb formation, and the aneurysm was > 7 mm in diameter and/or the dome-to-neck ratio was > 2.0. Multivariate logistic regression analysis showed age < 60 years (OR 4.3, p = 0.011), history of hypertension (OR 5.1, p = 0.008), lateral direction of the aneurysmal dome around the PCoA (OR 6.7, p = 0.0001), and bleb formation (OR 11, p < 0.0001) to be significantly associated with PCoA aneurysm rupture. CONCLUSIONS: The present results demonstrated that lateral projection of a PCoA aneurysm may be related to rupture.

Ultrasonography mapping combined with mammography before breast-conserving surgery for primary breast cancer with microcalcifications: a novel approach.

INTRODUCTION: Evaluation for the spread of breast cancer with microcalcifications is challenging, because the microcalcifications sometimes spread beyond the lesions detectable by ultrasonography (US). An original method for preoperative mapping was performed for such lesions, using US in combination with mammography (MG) (US + MG mapping) before breast-conserving surgery (BCS). MATERIALS AND METHODS: A total of 885 consecutive patients underwent BCS for primary breast cancer. Of the 885 patients, 154 (17.4%) with ductal carcinoma in situ or invasive carcinoma having microcalcifications underwent US + MG mapping preoperatively. Five patients who received neoadjuvant chemotherapy and 17 patients who were lost to follow-up were excluded. Accordingly, 133 lesions in 132 patients were retrospectively evaluated. The associations among this method, surgical margin (positive, close, or negative), pathologic characteristics, the area of the lesion within the specimen, and local recurrence rate during 5 years of follow-up were analyzed. RESULTS: The median age and follow-up duration were 51.3 years (range, 28-80 years) and 71.4 months (range, 60-79 months), respectively. The surgical margin was negative in 96 lesions (72.2%), close in 27 lesions (20.3%), and positive in 10 lesions (7.5%). Local recurrence was noted in 1 patient (0.8%). There was no significant association between surgical margin status and the presence of invasive carcinoma. Larger lesion area was significantly associated with positive or close margin (P = .027). CONCLUSION: US + MG mapping is useful and results in a high complete-resection rate and an extremely low 5-year local recurrence rate.

Significance of peribiliary oedema on computed tomography in diagnosis and severity assessment of acute cholangitis.

OBJECTIVES: To evaluate usefulness of peribiliary oedema on computed tomography (CT) in diagnosing acute cholangitis and assessing its severity. MATERIALS AND METHODS: Sixty patients (male 59%, mean age 67.3 years) who underwent endoscopic retrograde biliary drainage (ERBD) for suspected biliary obstruction within 6h after contrast-enhanced CT were evaluated. Two radiologists performed a consensus evaluation of CT for the presence of peribiliary oedema. Patients were divided into the cholangitis group and the non-cholangitis group based on clinical and ERBD findings, and CT results were compared between the two groups. In the cholangitis group, laboratory values and blood culture results were compared between those with and without peribiliary oedema. Chi-squared test was used for analyses. RESULTS: Of 60 enrolled patients, there were 46 patients in the cholangitis group and 14 patients in the non-cholangitis group. Peribiliary oedema was seen in 24/46 (52.2%) patients in the cholangitis group and 3/14 (23.3%) patients in the non-cholangitis group (p=0.043). In the cholangitis group, positive blood culture was seen in 12/24 (50%) patients with peribiliary oedema and 4/22 (18.1%) patients without it (p=0.03). CONCLUSIONS: Peribiliary oedema appears to be useful for diagnosis and severity assessment of acute cholangitis.

A case of lymphatic malformation/lymphangioma of the scrotum.

Lymphatic malformation/lymphangioma of the scrotum is rare. It is caused by lymphatic abnormalities and the most common sites are the neck and axilla. The scrotum is one of the most uncommon sites. We report the case of a 12-year-old boy with pathologically confirmed cystic lymphangioma/lymphatic malformation in the scrotum. The diagnosis was suspected from ultrasonography and magnetic resonance imaging. The most common cause of a cystic mass in the scrotum is scrotal hydrocele, but cystic lymphangioma/lymphatic malformation should be considered as a differential diagnosis for multicystic scrotal mass.