Lymphatic leakage is a recognized complication of lymphadenectomy. Intranodal lymphangiography is commonly used to identify lymphatic leakage; however, the procedure may not be feasible in cases where no puncturable lymph nodes remain following inguinal lymphadenectomy. We report a case of refractory lymphatic leakage occurring after inguinal lymphadenectomy that was managed by direct puncture and N-butyl cyanoacrylate (NBCA) embolization of a lymphocele and lymphopseudoaneurysm with lymphoscintigraphy employed for localization.A 70-year-old woman experienced persistent lymphatic leakage following left inguinal and external iliac lymphadenectomy for melanoma. Lymphoscintigraphy with single photon emission computed tomography/computed tomography revealed 2 disrupted lymphatic pathways along the great saphenous and femoral veins. Intense tracer accumulation at the inguinal stump along the great saphenous pathway indicated fluid collection, whereas tracer presence along the femoral pathway extended near the drainage catheter without focal pooling suggested communication with the drain tract. Due to the absence of puncturable lymph nodes, intranodal lymphangiography was not feasible. We punctured and embolized the fluid collection along the great saphenous pathway using an NBCA-ethiodized oil mixture. Despite this intervention, lymphatic leakage persisted; therefore, we accessed another small fluid collection along the femoral vein. Ethiodized oil injection demonstrated continuity with the drainage catheter which was consistent with a lymphopseudoaneurysm. Following embolization, the external lymphatic leakage resolved within several days.This case illustrated that lymphoscintigraphy can effectively identify major sites of leakage and guide intervention; however, intense tracer accumulation does not necessarily indicate the sole source of leakage when multiple lymphatic pathways are disrupted.

Mucinous cystic neoplasm of the liver (MCN-L) is a rare cyst-forming epithelial neoplasm that typically lacks bile duct communication. Intraductal protrusion is uncommon and can mimic cystic intraductal papillary neoplasm of the bile duct (IPNB). A 39-year-old woman undergoing fertility treatment presented with recurrent hyperbilirubinemia and predominantly cholestatic liver test abnormalities. MRI demonstrated a 10.5-cm multilocular cystic lesion in segment 4 of the liver with downstream biliary dilatation, and internal septa were visible within the dilated bile duct on T2-weighted single-shot fast spin-echo (SSFSE) images. Contrast-enhanced computed tomography (CT) revealed enhanced cyst wall and septa, while endoscopic retrograde cholangiography revealed a smooth, oval-shaped filling defect. Endoscopic and intraductal ultrasonography indicated septate cystic components of the bile duct, and biopsy revealed mucin-producing columnar epithelium overlying the ovarian-like stroma, confirming MCN. The patient was treated via extended left hepatectomy with extrahepatic bile duct resection and reconstruction. Pathological examination revealed low-grade intraepithelial neoplasia. The patient remained recurrence-free for 20 months. This case suggests that, although biliary communication usually favors cystic IPNB over MCN-L, identification of intraductal extension of the cyst wall or septa within the dilated bile duct may provide an important clue to the diagnosis of MCN-L.

Background:There has been growing interest in the limited resection of early-stage lung cancer. Imaging-based preoperative risk stratification is expected to improve outcomes, but has not yet been well established. This study aimed to develop an imaging-based model for predicting high-risk histopathological features in early T-stage lung adenocarcinoma to identify low-risk patients. Methods:We retrospectively enrolled patients with cTis or cT1 N0M0 resected adenocarcinomas who underwent thin-slice computed tomography (CT) and 18F-fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) at two institutions (Kyoto University Hospital as the training set and Hyogo Prefectural Amagasaki General Medical Center as the external test set). The thin-slice CT parameters analyzed included volume-based consolidation-to-tumor ratio (vCTR), diameter-based CTR (dCTR), tumor volume (TV), and doubling time (DT); while the FDG-PET/CT parameters comprised maximum standardized-uptake value (SUVmax), SUVmean, metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Histopathological risk-positive lesions were defined as positive for pleural, vessel, or lymphatic invasion; spread through air space (STAS); and International Association for the Study of Lung Cancer (IASLC) grade 3. Logistic regression was used to develop predictive models, which were then tested on the external test set. Results:We analyzed 190 lesions in 174 patients for the training set, and 34 lesions in 28 patients for the external test set. The parameters vCTR and SUVmax showed the highest area under the receiver operating characteristics curve (AUC) values for risk-positive lesions (vCTR >58%: 0.83; SUVmax >2.0: 0.87) as independent predictors. The AUCs of our model (predictors: vCTR, SUVmax) were 0.87 and 0.85 in the training and external test sets, respectively. Conclusions:We developed and externally validated an imaging-based model for predicting high-risk histopathological features in early T-stage lung adenocarcinoma. This model may prove valuable for identifying suitable candidate patients for limited surgery.

Nipple leiomyoma is a benign cutaneous tumor that arises from the smooth muscle fibers of the musculus areolae and represents the rarest subtype of cutaneous leiomyoma. Since its first description by Virchow in 1854, approximately 50 cases have been reported, with only 20 involving male patients. Imaging findings, particularly the MRI characteristics, have been insufficiently documented. We report a man in his 70s with a 10-year history of left nipple pain. Ultrasonography revealed a mildly irregular hypoechoic mass with increased vascularity. MRI demonstrated a well-defined, smoothly marginated mass with intermediate signal intensity on STIR and T1WI, a hypointense rim, and a slow, persistent contrast-enhancement pattern without diffusion restriction. Core needle biopsy confirmed a leiomyoma. The lesion was managed conservatively at the patient’s request. Recognition of the MRI characteristics of nipple leiomyoma may help the differential diagnosis of nipple lesions.

Varicella-zoster virus (VZV) can cause a wide spectrum of central nervous system (CNS) complications, including meningitis, encephalitis, and vasculopathy, occasionally in the absence of characteristic cutaneous manifestations. We report a case of fulminant VZV-associated CNS infection in an immunocompetent man in his 40s without rash, who presented with rapidly progressive impaired consciousness. Magnetic resonance imaging (MRI) revealed diffuse leptomeningitis, widespread intracranial vasculopathy, and extensive perivascular parenchymal lesions characterized by hemorrhage, necrotizing changes, and markedly restricted diffusion. Magnetic resonance angiography demonstrated irregular narrowing of the bilateral anterior and middle cerebral arteries, consistent with intracranial vasculopathy. Cerebrospinal fluid analysis using multiplex polymerase chain reaction detected VZV DNA, confirming the diagnosis. Despite antiviral therapy and supportive treatment, the clinical course was fatal. This case highlights that VZV CNS infection may produce aggressive perivascular destructive lesions beyond classic vasculopathy, even in patients without rash, and underscores the importance of comprehensive MRI evaluation in atypical fulminant presentations.

The bloomy rind sign, characterized by band-like abnormalities along the surface of the brainstem on magnetic resonance imaging without contrast enhancement, has been considered a specific imaging marker for leptomeningeal metastasis from lung adenocarcinoma. In this study, we describe the case of an 85-year-old male with a 3-week history of headache, fever, and progressive cognitive impairment. The patient was diagnosed with varicella-zoster virus brainstem meningoencephalitis and magnetic resonance imaging revealed hyperintensities along the brainstem surface on fluid-attenuated inversion recovery and diffusion-weighted imaging that mimicked a bloomy rind sign. However, the patient showed no signs of lung cancer or meningeal carcinomatosis. This case suggests that the bloomy rind sign is not exclusive to leptomeningeal metastasis but can also be observed in other conditions, such as central nervous system infections.

Ganglioneuroma is a well-differentiated tumor originating from neural crest cells of the sympathetic nervous system. Although benign, a few cases have been reported that ganglioneuroma can metastasize to other sites. We report a case of adrenal ganglioneuroma with para-aortic nodal metastases with low FDG and MIBG uptake. In order to avoid unnecessary wide excision or aggressive medication, it is important to consider the possibility of ganglioneuroma preoperatively even if with metastases.

Abstract In recent years, many articles have described the adverse events associated with immune checkpoint inhibitors. We report the case of a 63-year-old woman with bilateral lung shadows after 1-year pembrolizumab immunotherapy following surgery for the right-foot melanoma because of positive sentinel lymph nodes. Follow-up 18F-FDG PET/CT demonstrated bilateral diffuse mass-like peribronchovascular opacities with marked FDG uptake. Clinically, melanoma metastases with lymphangitic spread were suspected, and bronchoscopy was performed, although no evidence of malignancy was found. The lung shadow was mostly resolved after steroid treatment. Pembrolizumab-induced pneumonitis can be a mimicker of melanoma metastasis with lymphangitic spread.

Purpose The possibility of steroid administration inducing the extensive skeletal muscle uptake (ESMU) of FDG in PET scans was investigated. Methods From 8923 consecutive 18F-FDG PET/CT scans taken at our hospital, 23 scans (15 patients) met adult age and ESMU-positive inclusion criteria. Among the 15 patients, 13 with both ESMU-positive and -negative scans were examined for association with steroid administration. Results Extensive skeletal muscle uptake was associated with a history of steroid administration (χ 2 test: P = 0.001). Notably, 20 ESMU-positive scans and 11 ESMU-negative scans were significantly different, with 0 to 95 days (median, 18.5 days) and 0 to 708 days (median, 319.0 days) since the last steroid administration, respectively (Mann-Whitney U test, P = 0.003). A significant correlation was observed between mean skeletal muscle SUVmax and the number of days since the last steroid administration (Spearman rank correlation coefficient, ρ = −0.501, P = 0.004). Specifically, the degree of ESMU tended to decrease over time, after steroid administration. From multiple regression analysis, the number of days since the last steroid administration was significantly associated with mean SUVmax (P = 0.007), but the blood glucose level was not significant (P = 0.204), revealing that the number of days since the last steroid administration was an independent risk factor. Multicollinearity was low (the variance inflation factor was 1.007 for both the number of days since the last steroid administration and blood glucose levels). Conclusions Steroid administration within months before PET may be one cause of ESMU.

Metaplastic breast carcinoma in neurofibromatosis type 1 is extremely rare. There are few reports about dynamic contrast-enhanced MRI findings and sequential CT findings of metaplastic breast carcinoma in neurofibromatosis type 1. Herein, we report imaging findings, including dynamic contrast-enhanced MRI and sequential CT, of metaplastic breast carcinoma in an 82-year-old woman with neurofibromatosis type 1. Short tau inversion recovery image revealed an oval mass with a circumscribed margin that exhibited moderate intensity with partially hyperintense area inside, and T1-weighted imaging revealed a spotty hyperintense area. The solid component of the mass showed heterogeneous enhancement and the time-intensity curve had a fast/washout pattern with restricted diffusion. In addition, multiple neurofibromas were observed. Sequential CT revealed that the diameter of the mass doubled in 3 months without apparent lymph node metastasis. Because detection of metaplastic breast carcinoma in neurofibromatosis type 1 tends to be delayed due to multiple neurofibromas, characteristic MRI findings suggestive of metaplastic breast carcinoma and sequential CT findings are important for early treatment of metaplastic breast carcinoma in patients with neurofibromatosis type 1.

Pleomorphic adenoma commonly develops in the salivary gland, but rarely in the breast. The dynamic contrast-enhanced MR imaging findings of pleomorphic adenoma of the breast have not been well described. We report a 43-year-old woman with pleomorphic adenoma of the left breast. The imaging findings, including those on dynamic contrast-enhanced MR imaging, included an oval mass with a smooth margin, which consisted of solid and cystic components. The solid component was hypo-intense on T1-weighted imaging, hyper-intense on short tau inversion recovery imaging, with no apparent restricted diffusion, and had heterogeneous enhancement with dark internal septation and a fast/plateau dynamic contrast enhancement pattern. The cystic component was slightly hyper-intense on T1-weighted imaging, slightly hypo-intense on short tau inversion recovery imaging and had no apparent restricted diffusion or contrast enhancement. Together with its rarity, the similarities of imaging findings and the pathologic findings of pleomorphic adenoma of the breast to those of other tumors make accurate preoperative diagnosis difficult. Therefore, through this case report, awareness of pleomorphic adenoma of the breast on dynamic contrast-enhanced MR imaging will facilitate appropriate surgery and postoperative observation based on an accurate diagnosis.

Neonatal subpial hemorrhage has been underrecognized until recently and its pathophysiology remains unclear. Advances in magnetic resonance imaging have facilitated the identification of hemorrhage within the subpial space and cohort studies recently reported its imaging and clinical features. We encountered two cases of neonatal subpial hemorrhage along the medial side of the temporal lobe. Case 1: A 1-day-old boy had repeated apneic attacks with cyanosis from 2 hours after birth at 39 weeks of gestation by vacuum extraction delivery. Computed tomography and magnetic resonance imaging showed subpial hemorrhage from the medial to caudal side of the right temporal lobe with T2 prolongation in the underlying cerebral parenchyma. Case 2: A 0-day-old boy had repeated apneic attacks with cyanosis from 3 hours after birth at 39 weeks of gestation by vaginal delivery. Subpial hemorrhage was observed from the anterior to medial side of the left temporal lobe on computed tomography and magnetic resonance imaging. On magnetic resonance imaging, the adjacent brain parenchyma showed a hyperintense signal on T2-weighted imaging. No abnormalities or signs of fetal distress were noted in the course of delivery. A mildly prolonged activated partial thromboplastin clotting time, an elevated D-dimer level, and low fibrinogen level were detected in a blood examination after birth in both cases. Both cases had subpial hemorrhage along the medial side of the temporal lobe, which suggested that an external mechanical force with fetal head molding during delivery caused subpial hemorrhage; however, other factors, including coagulopathy, may be involved in its pathophysiology.

Cerebral proliferative angiopathy is a rare cerebrovascular disorder characterized by diffuse abnormal vessels with intermingled brain parenchyma fed by many arteries and draining into many veins without high-flow arteriovenous shunts, which is usually confirmed by conventional digital subtraction angiography. However, dilution of the contrast medium due to the markedly increased blood flow and volume in cerebral proliferative angiopathy leads to low-contrast angiography. We report a 53-year-old man with cerebral proliferative angiopathy who underwent CT, MR imaging, MR angiography, digital subtraction angiography and 4D-CTA. The 4D-CTA exhibited abnormal vessels without early venous filling between the atrophic brain parenchyma in higher contrast than the angiography due to high spatial and time resolution, whereas the left external carotid angiography visualized the characteristic transdural supply more clearly than the 4D-CTA due to high vascular selectivity. Therefore, novel 4D-CTA and conventional angiography plays a complementary role in the accurate diagnosis of cerebral proliferative angiopathy. Taking invasiveness into account, 4D-CTA may be advantageous for the diagnosis of cerebral proliferative angiopathy based on the characteristic imaging findings.

頚部脊髄髄症の一部に髄内に浮腫を認め, かつ造影MRIでGd増強効果がみられることがあり, 早期の減圧手術によって良好な治療成績が得られる. しかしGd増強部位の術後経過についてまとめて検索した報告例は少ない. 当院における頚部脊髄症3例のMRI画像では脊髄浮腫による髄内T2高信号と最狭窄部位での髄内Gd増強効果を認めた. そこでこの3例と, 造影MRIの画像比較が可能であった文献報告13例を含めて全16例につき造影MRI画像の術前から術後の経過を検討した. 13例の術前画像の特徴は本報告3例と同様であり, 術後にGd増強部位は61%で1～3年以内に著明に縮小ないし消失した. 脊髄腫脹のメカニズムは第一に静脈系を中心とした脊髄血流障害によるもの, 第二に髄液還流障害によるものが挙げられるが, 頚椎過伸展も影響している可能性がある.

Vessel wall MR imaging (VW-MRI) has been introduced into clinical practice and applied to a variety of diseases, and its usefulness has been reported. High-resolution VW-MRI is essential in the diagnostic workup and provides more information than other routine MR imaging protocols. VW-MRI is useful in assessing lesion location, morphology, and severity. Additional information, such as vessel wall enhancement, which is useful in the differential diagnosis of atherosclerotic disease and vasculitis could be assessed by this special imaging technique. This review describes the VW-MRI technique and its clinical applications in arterial disease, venous disease, vasculitis, and leptomeningeal disease.

Inverted papilloma originating from the lacrimal sac and the nasolacrimal duct is rare, although that in the sinonasal region is a relatively common lesion with local invasion, malignant potential and high recurrence rates after surgery. We report a 52-year-old woman with inverted papilloma of the right lacrimal sac and the nasolacrimal duct, who underwent CT, MR imaging and FDG-PET/CT preoperatively. In addition to CT and MR imaging features similar to those in previous reports, the inverted papilloma exhibited marked FDG accumulation with a maximum standardized uptake value of 7.34 and no other significant FDG accumulation was detected. In summary, our case of inverted papilloma originating from the right lacrimal sac and the nasolacrimal duct noted marked FDG accumulation on PET/CT, which enabled visualization of the localized tumor extension with no metastases.

ABSTRACT:A 74-year-old man with diffuse large B-cell lymphoma underwent 18F-FDG PET/CT to evaluate the response to chemotherapy. Although granulocyte colony-stimulating factor was incidentally administered 1 hour before FDG administration, bone marrow FDG accumulation did not increase compared with the previous 18F-FDG PET/CT examination without granulocyte colony-stimulating factor administration. The mean SUVmax of 12 thoracic and 5 lumbar vertebrae was 2.55 (range, 2.14-3.36) and 3.19 (range, 2.49-4.28) in the present and previous examinations, respectively.

A 62-year-old man with liver cirrhosis presented with deterioration of liver function. Imaging studies revealed an arteriovenous malformation (AVM), with a dilated venous space, at the pancreatic head. Transarterial embolization of the AVM, using microcoils, was performed, although many feeding arteries remained. As the transarterial embolization was incomplete, further liver function deterioration was a possibility. In fact, 1 year after the procedure, the patient was referred back to our hospital for treatment of massive ascites and liver function deterioration. Transportal embolization of the dilated venous space was performed, using microcoils via the recanalized paraumbilical vein, with no enhancement of the AVM. No complications occurred. Based on our experience, we propose transportal embolization as an effective treatment option for pancreatic AVM.

A 73-year-old man with lung cancer underwent bone scintigraphy for disease staging. Diffuse myocardial technetium hydroxymethylene diphosphonate (99mTc-HMDP) uptake was incidentally found. A diagnosis of amyloid transthyretin (ATTR) cardiac amyloidosis was suspected, although the patient had no symptoms at this time. Single-photon emission computed tomography (SPECT) showed particularly strong uptake in the ventricular septum. Cardiac magnetic resonance imaging (CMR) showed widespread subendocardial and partly transmural enhancement of the left ventricular myocardium on delayed postcontrast T1-weighted images. These findings were consistent with ATTR cardiac amyloidosis. 18F-FDG uptake in the left ventricle wall was observed on PET/CT. He was finally diagnosed with ATTR by endomyocardial biopsy. There are two major subtypes of cardiac amyloidosis: ATTR amyloidosis and amyloid light-chain (AL) amyloidosis. Endomyocardial biopsy is the gold standard for diagnosis. Recently, however, several reports have shown that bone scintigraphy using a 99mTc-labelled bone-seeking agent can detect ATTR cardiac amyloidosis and differentiate it from AL amyloidosis. Bone scintigraphy may play an important role in the detection and differentiation of ATTR cardiac amyloidosis.

Fetus in fetu (FIF) is a rare congenital anomaly resulting from abnormal embyogenesis in monochorionic diamniotic twins and appears as a cystic mass containing fetus-like structures mainly in the retroperitoneum of infants. Although there is a theory that FIF is a highly differentiated teratoma, it is commonly distinguished from teratoma as a mass containing a vertebral axis with appropriate arrangement of limbs or other organs around this axis. Here we present a case of FIF with aorta-like structure visualized by contrast-enhanced computed tomography. A 5-day-old girl was pointed out a cystic mass in the abdomen by ultrasound examination. Abdominal contrast-enhanced computed tomography revealed a retroperitoneal cystic mass with spine- and limb-like bone structures and blood vessel-like elongated structures and it was confirmed as FIF by surgery. The presence of major vascular structures along the skeletal axis is clearly different from teratoma and suggests that it occurred as an embryo and underwent some stage of development. Our findings strongly support the monozygotic twin theory.