Inflammatory pseudotumor

Inflammatory myophibroblastic tumor of the proximal ileon in a patient with complicated umbilical hernia: A case report and literature review

Introduction

Inflammatory myofibroblastic tumors are neoplasms that occur infrequently, mainly affects children and young adults. It is an intermediate grade fibrotic multinodular neoplasm.

Description of the case

We present the case of a 47-year-old female patient, who underwent emergency umbilical hernioplasty, later developed intestinal obstruction secondary to an inflammatory myofibroblastic tumor.

Discussion

In 1939 Brunn described it for the first time, later in 1954 Umiker named it “Inflammatory Myofibroblastic Tumor”. The symptoms are nonspecific. In 15 to 40% of patients they are asymptomatic. Cells positive for actin, smooth muscle, vimentin and desmin, in 3367% of cases the cells are positive for ALK, which is present in some malignant lesions. The recommended treatment is radical resection.

Conclusion

The diagnosis is established by histopathological study, surgery is the cornerstone of treatment.

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Rare case of intestinal myofibroblastic tumor

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Inflammatory myofibroblastic tumors are infrequent tumors with benign behavior most of the time.

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Myofibroblastic tumor of unusual presentation

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Complete resection as the treatment of choice in myofibroblastic tumors

Inflammatory myofibroblastic tumor of gingiva in a patient with constitutional growth delay: A rare case report

Several disorders related to growth and development affect children during their early stages of life. One rare disorder that affects about 15% of children is constitutional growth delay (CGD). Its results in the affected individuals appear unusually short and young for their age. The individuals are otherwise normal and appear as their normal counterparts as age increases. Inflammatory myofibroblastic tumor (IMT) is a rare soft-tissue tumor that commonly affects the lungs, liver, and gastrointestinal tract. The occurrence of this tumor outside the aforementioned areas is very rare. It resembles a neoplastic tumor clinically and histologically. It is also referred to as inflammatory pseudotumor. Here, we report the case of an individual with CGD who also had an IMT involving the mandibular left canine region.

Intracranial Inflammatory Pseudotumor: A Case Report

: Primary inflammatory pseudotumor of the central nervous system is extremely rare. These lesions may be intra-axial, extra-axial, or a mix of them. We report a case of intracranial inflammatory pseudotumor involving both brain parenchyma and dura.

Cervical Sympathetic Trunk-Centered Inflammatory Myofibroblastic Tumor Complicated with Postoperative First Bite Syndrome

Inflammatory myofibroblastic tumors (IMTs) in the head and neck region are common, but those with sympathetic trunk involvement are extremely rare. Here we present a case of cervical sympathetic trunk-centered IMT which is also accompanied by ipsilateral carotid artery, internal jugular vein, and vagus nerve involvement. The patient initially complained of an episodic painful swelling on the right side of the neck and underwent surgery. Preoperative and postoperative serum IgG4 level during 3-year follow-up time is within normal limits. Immunohistochemical study of the tumor has also revealed negativity to IgG4. Postoperative first bite syndrome (FBS) was observed. Surgery seems to be first-line therapy in the patient with IgG4-negative IMT.

Sinonasal inflammatory myofibroblastic tumour: a rare entity with diagnostic challenges

Inflammatory myofibroblastic tumour is a rare entity causing sinonasal involvement with variable behaviour. Mimicking various benign and malignant lesions, accurate diagnosis is often clinched on histopathology complemented with appropriate immunohistochemistry markers. Surgical resection is the main treatment modality with other forms of therapy reserved for unresectable lesions. We highlight a case of dual involvement of the sinonasal region and nasal bones along with the diagnostic and treatment challenges encountered. As the nasal bones were involved, surgical resection with negative margins required cosmetic reconstruction in the same sitting. A costochondral graft helped in achieving cosmetic pleasing results with no recurrence on follow-up.

Intratumor Abscess in a Posttraumatic Hepatic Inflammatory Pseudotumor Spreading Out of the Liver

A 45-year-old woman with abdominal pain after minor trauma was referred to our hospital. Computed tomography (CT) showed a hypovascular tumor in the left liver lobe. A tumor biopsy revealed granuloma, although no findings indicated malignancy or infection. A follow-up imaging study showed spread of the hepatic tumor. Her abdominal pain worsened after a second minor trauma. CT revealed an intratumor abscess, and pus overflowed from the patient's umbilicus. The abscess was improved by antibiotics and drainage therapy. In this case, unusual imaging findings and an atypical disease course of a hepatic inflammatory pseudotumor were observed.

Inflammatory Myofibroblastic Tumor of the Liver Mimicking Metastasis on 18F-FDG PET/CT

A 62-year-old woman with history of stage III endometrial cancer was found to have a small enhancing liver lesion on follow-up abdominal CT and MRI, suspicious for metastasis. Subsequent F-FDG PET/CT was performed, demonstrating intense uptake within the liver lesion, consistent with metastasis. Subsequently, laparoscopic wedge liver lesion resection was performed. Histopathologic examination confirmed the diagnosis of inflammatory myofibroblastic tumor (IMT) with predominant inflammatory cells. Although solitary liver IMTs are rare occurrences with imaging features overlapping with malignancy, IMT should be considered in the differential diagnosis of suspicious liver lesions, especially when the pattern of spread is unusual.

Inflammatory Pseudotumor: A 20-Year Single Institutional Experience

Background:

Inflammatory pseudotumor (IPT) is a relatively rare benign disease. The aim of the study was to demonstrate the demographic distribution, clinical presentation, and histomorphological characteristics of IPT while highlighting its associated diagnostic challenges.

Materials and Methods:

A retrospective cross-sectional review of all the IPT diagnosed in our institution between January 1999 and December 2018 was conducted. The samples were received from within and outside the hospital facility. The demographic data, clinical history, and histologic reports were reviewed.

Results:

A total of 25 cases of histologically confirmed IPT were seen. Patients' age ranges from 7 to 74 years with a mean age of 38.96 years and standard deviation ± 17.94 years. There was a bimodal peak occurrence in the third and fifth decades. Most of the patients were adults (23, 92%), whereas only 2 (8%) were children. There was a female preponderance with a male-to-female ratio of 1:2.6. The head and neck had the highest number of cases (44%), followed by the gastrointestinal tract (GIT) (40%). Eight (73%) of head and neck cases occurred in the orbit. The presenting complaints depended on the site of the lesion with pain and swelling being the commonest symptoms irrespective of the site of the lesions. Two cases of bilateral IPT were observed. Immunohistochemistry was used in a certain condition of diagnostic dilemma.

Conclusion:

This study showed a female preponderance of IPT with the head and neck and GIT being the most common location. It is important to rule out other differentials in the diagnosis of IPT.

Rare presentation of inflammatory pseudotumour involving subcutaneous tissues with superficial fat sparing

We present a unique case of inflammatory pseudotumour involving gluteal subcutaneous tissue with the sparing of superficial fat and report its contrast-enhanced CT, F-18 fluorodeoxyglucose positron emission tomography/CT and pathological findings. Although rare, inflammatory pseudotumours have been reported with a diverse spectrum of locations; however, the involvement of the subcutaneous tissue overlying the gluteal muscles with sparing of the most superficial fat has not been reported.

Inflammatory myofibroblastic tumor of the lung: A rare endobronchial mass

A 42-year old male was referred with a 6-week history of new onset dyspnea. The patient had normal vital signs, no relevant medical history and the only abnormality was a left sided inspiratory wheeze. No abnormalities were seen on the chest X-ray. A bronchoscopy was performed which showed a well-circumscribed hypervasculated mass in the left main bronchus. A biopsy was taken, which was complicated after the procedure by dislocation of the mass and coughed up by the patient. Both samples were send for pathologic review. A contrast CT was performed which showed a localized remaining mass in the left main bronchus and no lymph node involvement. Pathological evaluation showed spindle-shaped cell proliferation with mitotic activity in the second larger tissue which could be consistent with an inflammatory myofibroblastic tumor (IMT), whereas the first biopsy sample only showed granulomatous inflammation. Following multidisciplinary review the diagnosis of IMT was made and a treatment plan was decided. Because of the localized position of the mass the patient was treated with laser coagulation via rigid bronchoscopy instead of surgery. Bronchoscopic review afterwards showed complete resolution of the mass and the dyspnea had resolved. This case highlights the difficulty of making the IMT-diagnosis and the option of treating it with laser coagulation via rigid bronchoscopy.

Anaplastic lymphoma receptor tyrosine kinase-negative inflammatory myofibroblastic tumor of triceps brachii: Case report

Inflammatory myofibroblastic tumor (IMT) is a non-neoplastic benign lesion comprising various inflammatory cells, including myofibroblasts and vascular tissues. It is a rare tumor that sometimes shows similar signs and progression as malignant tumors. The anatomical sites of IMTs include the lungs, liver, orbit, skin, mesentery, and maxillary sinus, but they rarely occur in the limb musculoskeletal system. To our knowledge, no case of neurological symptoms caused by the tumor in the triceps brachii muscle has been reported. In this article, we report the case of a 42-year-old male patient with an IMT that grew rapidly in the triceps brachii muscle and consequently caused symptoms of ulnar nerve lesion owing to its increasing size. The patient showed no ulnar nerve lesion symptoms after undergoing wide excision and was diagnosed with anaplastic lymphoma receptor tyrosine kinase- negative IMT.

Inflammatory Pseudotumor of Intestine Mimicking Lymphoma on 18F-FDG PET/CT

A 45-year-old man with suspected colonic malignancy was referred to F-FDG PET/CT for staging. PET/CT images showed segmental increased FDG uptake along the intestine with thickening of colonic wall, where no mass was obviously seen. Subsequently, left hemicolectomy and resection of partial small intestine were done. Histopathology of the resected specimen confirmed the diagnosis of inflammatory pseudotumor involving colon and small intestine. No recurrence was detected on follow-up CT images after 6 months. Although most of the previously reported intestinal inflammatory pseudotumor manifested as a mass, it should be considered as a differential diagnosis of FDG-avid segmental intestinal wall thickening.

The pediatric stomach - masses and mass-like pathology

Diagnostic imaging of pediatric gastric masses often provides a challenge for the practicing radiologist. Radiologists should be aware of this relatively unusual pathology, particularly in cross-sectional imaging findings. We will review pediatric gastric masses and mass-like lesions, focusing on neoplastic and inflammatory etiologies.

Inflammatory myofibroblastic tumours of the thorax: Radiologic and clinicopathological correlation

CONTEXT AND AIMS

Inflammatory myofibroblastic tumour (IMT) is a rare mesenchymal neoplasm with intermediate malignant potential. The aim of this study is to describe and compare the clinical presentation, computed tomography (CT) findings and anaplastic lymphoma kinase -1 (ALK-1) expression of IMT of the thorax in children and adults. We also sought to study the tumour behaviour after treatment on the follow-up imaging.

MATERIALS AND METHOD

This is a retrospective observational study of 22 histopathologically proven cases of IMT in the thorax. The clinical parameters, CT findings, biopsy results, treatment received and follow-up were recorded. Statistical analysis was performed using Fisher's exact test.

RESULTS

IMT of the thorax had diverse imaging appearances, presenting either as large invasive lung masses with or without calcifications or as smaller endobronchial lesions. Children commonly presented with long duration fever (P = 0.02) and large invasive lung masses (P = 0.026), whereas adults presented with long duration haemoptysis (P = 0.001) and endobronchial lesions or smaller lung parenchymal lesions. Calcifications were more common in children (P = 0.007). ALK-1 was positive in 40% of children and 18.2% of adults (P = 0.547). Endobronchial lesions showed a trend for ALK-1 negativity. Patients with bronchoscopic excision had local recurrence and patients with surgical wedge resection had metastatic brain lesions as compared to those with lobectomy and pneumonectomy (P = 0.0152). A patient with unresectable lung mass had malignant transformation to spindle cell sarcoma after 9.5 years.

CONCLUSIONS

Thoracic IMT presents with some distinct clinical and CT findings in adults and children. The CT findings and management options have implications for prognosis. If resectable, lobectomy is a better option than wedge resection or bronchoscopic excision for preventing local recurrence and metastasis. IMT can undergo malignant transformation.

Rare presentation of inflammatory myofibroblastic tumor in the kidney

Inflammatory myofibroblastic tumor (IMT) is a rare pathologic entity that has been mostly described in the lung. It has been reported in nearly every organ, with occurrence in the kidney being extremely rare. IMT has nonspecific clinical and radiological findings and often mimics a malignant process. This is a case discussing the radiologic and pathologic findings of a renal IMT in a 35-year-old female who underwent radical nephrectomy for a right renal pelvis mass that was mistaken for transitional cell carcinoma.

Spontaneous pneumothorax caused by an inflammatory myofibroblastic tumor-like lesion in a 14-year-old girl: a case report

Background

Spontaneous pneumothorax occurs more often in younger, slim, and shallow-chested men. Although less common, differential diagnoses for secondary pneumothorax in children are asthma, emphysematous blebs, catamenial pneumothorax, and others. We report a patient who presented with pneumothorax and was found to have an inflammatory myofibroblastic tumor (IMT)-like lesion, and present a review of the related literature.

Case presentation

A 14-year-old girl visited her physician for chest pain that developed while exercising. Although chest drainage was performed, the symptoms associated with a collapsed lung did not improve, and she was referred to our hospital. Computed tomography revealed the presence of a 19 × 17-mm cyst with a thick wall in the apex of the right lung. She was tested for infectious diseases, namely tuberculosis, but the results were not definitive. Catamenial pneumothorax was also suspected because she was menstruating when she presented to our hospital. As a therapeutic diagnosis, we performed a thoracoscopic partial resection of the right upper lobe of the lung. Three small openings were identified inside the cyst, suggesting connection with the bronchiole. The lesion was pathologically diagnosed as an IMT-like lesion. Considering the progress so far, we considered that the final diagnosis to be an IMT. The patient was discharged on postoperative day 3, and we have followed her for the past 6 months with no local recurrence or metastasis.

Conclusions

IMT is not uncommon in children. Therefore, this lesion should be considered as a possible diagnosis if children and young adults develop spontaneous pneumothorax.

Radiographic and Endoscopic Features of Pancreaticoduodenal Malakoplakia

Malakoplakia is a rare, granulomatous disorder that is typically triggered by infections in immunocompromised patients. Although it most commonly affects the urinary tract, cases may occasionally occur in the gastrointestinal tract. There are case reports of malakoplakia of the pancreas with associated pathologic description, but none with detailed imaging and endoscopic findings. In addition, description of magnetic resonance imaging characteristics of mass-forming malakoplakia in the literature is sparse. We present a case of pancreaticoduodenal malakoplakia in an immunocompromised patient, including detailed description of magnetic resonance imaging, computed tomography, and endoscopic findings with radiology-pathology correlation. Classic pathologic features of malakoplakia (eg, hypercellularity, inflammation, and mineralization of Michaelis-Gutmann bodies) lead to specific features on imaging, such as marked diffusion restriction, heterogeneous enhancement, calcification, and increased attenuation on nonenhanced computed tomography. These features may help differentiate malakoplakia from other more common lesions that occur in this location, especially if present in an immunocompromised patient.

Overlooked and Challenging Encounters–Inflammatory Pseudotumors in the Abdomen and Pelvis: A Pictorial Essay

Inflammatory pseudotumors (IPTs) are uncommon, mass-forming lesions, predominantly involving the lung and orbit. Although the incidence of IPTs is rare in the abdomen and pelvis, they can be encountered as enhancing, soft-tissue lesions, mimicking malignancy or fibrosclerosing disease. Generally, they exhibit a wide range of nonspecific imaging features in various organs. Preoperative imaging diagnosis of IPTs in appropriate clinical settings may help determine proper patient management. In this article, we review radiologic findings of IPTs in the abdominopelvic cavity, including the liver, spleen, kidney, gastrointestinal tract, mesentery, pelvis, and retroperitoneum.

Inflammatory myofibroblastic tumor of the spermatic cord: two cases and review of the literature

Inflammatory myofibroblastic tumor (IMT) is a neoplasm of intermediate biological potential. Few cases of spermatic cord IMT have been reported in the literature. Inflammatory myofibroblastic tumor is a consequence of the proliferation of fibroblasts and inflammatory cells. Despite its benign nature, the tumor often clinically mimics intrascrotal malignancy and usually remains undiagnosed preoperatively. The diagnosis of spermatic IMT is difficult preoperatively due to the non-specific findings. Therefore, if testicular tumors cannot be precisely excluded, radical orchiectomy should be performed for the diagnosis and treatment. However, it mainly occurs in children and young adults; spermatic IMT may also be seen among elderly men. Here, we report two cases of inflammatory myofibroblastic tumor involving the spermatic cord. SIMILAR CASES PUBLISHED: There are seven cases entitled "inflammatory myofibroblastic tumor of spermatic cord" in the literature. In our study we present two cases that had a spermatic cord IMT. Furthermore, one of these cases was 82 years of age and is the oldest patient presented in the literature.

Imaging and pathological findings of intramedullary inflammatory pseudotumour in a miniature dachshund: a case report

Background

Inflammatory pseudotumours (IPTs) are distinctive lesions consisting of myofibroblastic spindle cells and a variety of inflammatory cells. The aetiology of IPTs is unknown. Reports of IPTs in veterinary medicine have been scarse. Moreover, only one case of intradural extramedullary IPT has been previously reported. In this report, we introduce the first known case of canine IPT, which occurred in the parenchyma of the spinal cord.

Case presentation

A 10-year-old female Miniature Dachshund presented with a 2-month-long history of progressively worsening ataxia and tetraparesis. Neurological examination was consistent with a lesion involving the cervical spinal cord. Magnetic resonance imaging revealed an intradural space-occupying lesion in the region of the fourth cervical vertebra. Dorsal laminectomy and resection of the mass were performed. Histopathological examination revealed the proliferation of immature spindle cells (fibroblasts/myofibroblasts and glial cells) and a highly cellular mixture of neutrophils, macrophages and lymphocytic cells. The mass was located in the parenchyma of the spinal cord and was diagnosed as an IPT occurring in the parenchyma of the spinal cord. No causative pathogen was detected. The dog’s symptoms improved, during the first month after surgery. However, neurological symptoms, such as laboured breathing and dysuria, subsequently worsened and the dog died 42 days after surgery.

Conclusions

The present study describes a canine case of IPT occurring in the parenchyma of the spinal cord. The diagnosis and determination of the site of the mass was difficult solely based on preoperative imaging in the present case. The outcome of this case was poorer than that observed in cases of canine extramedullary IPT and human intramedullary IPT, in which the patients exhibited recovery. The prognosis after surgical resection cannot be decided from the present case alone. However, patients should be monitored for potential serious complications and recurrence.

Anaplastic lymphoma kinase-negative pulmonary inflammatory myofibroblastic tumor with multiple metastases and its treatment by Apatinib: A case report

RATIONALE

Primary pulmonary inflammatory myofibroblastic tumor (IMT) with distant metastasis is extremely rare. Moreover, metastasis of pulmonary IMT to bone marrow has never been reported in previous studies. Therapeutic approaches for anaplastic lymphoma kinase (ALK)-negative pulmonary IMT with metastasis are limited. Yet there is no report on the treatment of advanced IMT cases with anti-angiogenesis drugs.

PATIENT CONCERNS

We described a patient with a complaint of fatigue, with the chest computed tomography (CT) scan revealing 2 masses in bilateral lung.

DIAGNOSES

The CT-guided lung biopsy examined 1 lesion in the right lung, and the post-operative pathological diagnosis of ALK-negative pulmonary IMT was recommended. However, the lung lesions were found significantly enlarged during the subsequent visit 8 months later, along with multiple metastases to the bone and abdominal cavity. A bone marrow biopsy revealed bone marrow infiltration by spindle cells.

INTERVENTIONS

The patient began to take Celecoxib due to the rapid progression of IMT, however, resulting in the aggravated gastric ulcer. He stopped taking the medicine 1 month later, with no remarkable change in the lesions by CT. Apatinib was administrated instead of Celecoxib.

OUTCOMES

After the 5-month treatment of Apatinib, the mass in the abdominal cavity significantly shrank and the lung lesions slightly decreased in size. With the 9-month administration of Apatinib, the lung lesions and the abdominal mass kept stable, compared with the situation in the 5-month follow-up.

LESSONS

Although pulmonary IMT shows the potential of metastasis, its metastasizing to bone marrow is a highly unusual event. Apatinib is effective for pulmonary IMT, and should be taken into consideration for the treatment of inoperable pulmonary IMT patients who lack ALK rearrangement.

How long should we continue crizotinib in ALK translocation-positive inflammatory myofibroblastic tumors? Long-term complete response with crizotinib and review of the literature

INTRODUCTION

Inflammatory myofibroblastic tumor is a rare disease which is typically seen in children and young adults. Approximately half of the inflammatory myofibroblastic tumors contain translocations that result in over-expression of anaplastic lymphoma kinase gene. Herein, we present two anaplastic lymphoma kinase-positive cases with long-term remission with crizotinib. We do not know how long these therapies need to be continued.

CASE REPORTS

We present two cases of inflammatory myofibroblastic tumor treated with anaplastic lymphoma kinase inhibitor therapies: an 8-year-old Turkish boy and a 21-year-old Caucasian man.

MANAGEMENT AND OUTCOME

Two cases, both with good tumor control under crizotinib, but one who progressed on drug holiday, responded again to the same drug, and had a very short period of response after restarting crizotinib.

CONCLUSION

A molecular-targeted drug (anaplastic lymphoma kinase inhibitor) was found to be extremely effective as selective therapy for inflammatory myofibroblastic tumor with anaplastic lymphoma kinase translocation. Here, we want to emphasize the continuation of this treatment after achieving a good response until progression or a major side effect.

Primary Lung Tumors in Children: Radiologic-Pathologic Correlation From the Radiologic Pathology Archives

Primary lung tumors in children are rare, with a narrow range of diagnostic considerations. However, the overlapping imaging appearances of these tumors necessitate attention to key discriminating imaging and pathologic features. In the neonate and infant, the important considerations include pleuropulmonary blastoma (PPB), infantile fibrosarcoma, and fetal lung interstitial tumor. Among these tumors, imaging findings such as air-filled cysts in type 1 PPB and homogeneously low attenuation of fetal lung interstitial tumors are relatively specific. Key pathologic and genetic discriminators among this group of tumors include the DICER1 germline mutation found in PPB and the t(12,15)(p13;q25) translocation and ETV6-NTRK3 fusion gene seen in infantile fibrosarcoma. Primary lung tumors in older children include inflammatory myofibroblastic tumors (IMTs), carcinoid salivary gland-type tumors of the lung, recurrent respiratory papillomatosis, and other rare entities. IMT, a spindle-cell proliferation with inflammatory elements, is the most common lung tumor in children. Anaplastic lymphoma kinase, a receptor-type protein tyrosine kinase, is present in 50% of these tumors, and this finding may support an imaging diagnosis of IMT. Carcinoid tumors account for a substantial portion of childhood lung tumors, and their characteristic avid enhancement on images corresponds to the compressed fibrovascular stroma histologically. Furthermore, novel imaging agents used with somatostatin receptor analogs have an emerging role in the evaluation of carcinoid tumors. Although less common than mucoepidermoid carcinoma, adenoid cystic carcinoma tends to recur given the perineural spread seen histologically. Integrating radiologic and pathologic knowledge is critical to accurate diagnosis, treatment planning, and surveillance of primary lung tumors in children.

Sonographic Evaluation of Genitourinary Inflammatory Pseudotumors and Its Mimics

Inflammatory pseudotumor is a relatively rare, nonneoplastic lesion composed of inflammatory cells and myofibroblastic spindle cells that can be identified on sonographic evaluation of the genitourinary system. These lesions are thought to be an inflammatory response to insults such as surgery, trauma, infection, or malignancy. Such lesions need to be distinguished from true neoplasms and other benign lesions, including inflammatory responses and infectious processes. Identification of inflammatory pseudotumors and its mimics is important for radiologists to guide patient treatment and follow-up. This pictorial essay presents sonographic features of inflammatory pseudotumors of the genitourinary tract and its mimics with cross-sectional imaging and histopathology, where available.

Animal model of left atrial thrombus in congestive heart failure in rats

The aim of the present study was to develop and study a new model of left atrial thrombus (LAT) in rat with congestive heart failure (CHF). CHF was induced by aortic banding for 2 mo, followed by ischemia-reperfusion (I/R) and subsequent aortic debanding for 1 mo. Cardiac function and the presence of LAT were assessed by echocardiography. Masson's staining was performed for histological analysis. All CHF rats presented with significantly decreased cardiac function, fibrosis in remote myocardium, and pulmonary edema. The incidence rate of LAT was 18.8% in the rats. LAT was associated with severity of aortic constriction, aortic pressure gradient, aortic blood flow velocity, and pulmonary edema but not myocardial infarction or a degree of left ventricular depression. The progressive process of thrombogenesis was characterized by myocyte hypertrophy, fibrosis, and inflammation in the left atrial wall. Fibrin adhesion and clot formation were observed, whereas most LAT presented as a relatively hard "mass," likely attributable to significant fibrosis in the middle and outer layers. Some LAT mass showed focal necrosis as well as fibrin bulging. Most LAT occurred at the upper anterior wall of the left atrial appendage. Aortic debanding had no significant impact on large LATs (>5 mm2) that had formed, whereas small LATs (<5 mm2) regressed 1 mo after aortic release. LAT is found in a rat model of aortic banding plus I/R followed by aortic debanding. The model provides a platform to study molecular mechanisms and potential new pathways for LAT treatment. NEW & NOTEWORTHY It is critically important to have a rodent model to study the molecular mechanism of thrombogenesis in the left atrium. Left atrial thrombus (LAT) is not a simple fibrin clot like those seen in peripheral veins or arteries. Rather, LAT is a cellular mass that likely develops in conjunction with blood clotting. Studying this phenomenon will help us understand congestive heart failure and promote new therapies for LAT.

Extra-skeletal Ewing Sarcoma of the chest wall in a child

Chest wall or pleural-based tumours represent a heterogeneous group of lesions that are infrequent in children and infants; however, a large proportion of these lesions are malignant in nature. Categorising them on the basis of primary versus secondary, site of origin (osseous and cartilage, or soft tissue) and tissue composition may assist in narrowing the differential diagnosis. We present a case of a 7-year-old boy with a progressive history of dyspnoea. The initial chest radiograph (CXR) demonstrated complete opacification of the left hemithorax with no air bronchograms. This was associated with the cut-off of the left main bronchus and mediastinal shift to the right. The post-contrast computed tomography (CT) of the chest showed multiple left-sided enhancing pleural-based masses with collapse of the left lung. These lesions were locally invasive as demonstrated by the intra and extra-thoracic extension. There were no associated erosions of the adjacent ribs or intra-tumoural calcifications. Based on the imaging findings, the diagnosis of extra-skeletal Ewing sarcoma (ES-EWS) of the chest wall was made with a differential diagnosis of rhabdomyosarcoma. A core biopsy was performed of the pleural-based mass, and histology with immunohistochemistry confirmed the diagnosis of a malignant small round blue cell tumour; subtype Ewing sarcoma family tumour (ESFT). The child was subsequently commenced on chemotherapy. The diagnosis of ES-EWS should be considered when a child or adolescent presents with an ill-defined, eccentric, chest wall mass in the absence of a lesion with a primary osseous origin. Imaging plays a key role in tumour staging, therapeutic planning and follow-up of patients.

Hepatic methotrexate-associated lymphoproliferative disorders identified by multiple liver tumors: a case report and review of the literature

Background

Methotrexate, an immunosuppressant, is widely used as the standard therapeutic drug for rheumatoid arthritis. With the increasing frequency of use of methotrexate, adverse effects of methotrexate have been reported, one of which is known as methotrexate-associated lymphoproliferative disorders. The etiology of hepatic methotrexate-associated lymphoproliferative disorders remains largely unknown. To date, there have only been ten cases of hepatic methotrexate-associated lymphoproliferative disorders reported in the English literature and a case report is very rare.

Case presentation

An 82-year-old Japanese man with rheumatoid arthritis treated with methotrexate presented with fever. Contrast-enhanced computed tomography showed multiple hypovascular nodules in his liver, spleen, and lung, and para-aortic lesions. Endoscopic ultrasound-guided fine-needle aspiration biopsy for liver tumors was performed, and pathological results identified cluster of differentiation 20-positive lymphocytes. Discontinuance of methotrexate led to regression of the nodules and a final definitive diagnosis of methotrexate-associated lymphoproliferative disorders was made.

Conclusions

We review 11 reported cases of hepatic methotrexate-associated lymphoproliferative disorders including the present case. Physicians should discontinue methotrexate in patients with rheumatoid arthritis treated with methotrexate when elevated soluble interleukin-2 receptor and hypovascular lesions in contrast-enhanced computed tomography are confirmed considering the possibility of methotrexate-associated lymphoproliferative disorders.

Clinical significance of IgG4 in sinonasal and skull base inflammatory pseudotumor

INTRODUCTION

Inflammatory pseudotumor (IPT) in the sinonasal cavity and skull base region is benign non-neoplastic inflammatory process. However, IPT can mimic malignant tumor or infectious disease and there are difficulties in confirmation of diagnosis. The aim of study is to evaluate the clinical significance of immunoglobulin G4 (IgG4) in IPT in terms of steroid response and differential diagnosis with other skull base infiltrative lesions.

METHODS

Medical records were reviewed retrospectively from 1998 to 2016. Subjects diagnosed with IPT by surgical biopsy were enrolled. IgG4 positivity was defined as IgG4/IgG ratio > 0.4. Additionally, IgG4/IgG ratio was calculated in eight skull base osteomyelitis (SBO) patients.

RESULTS

Twenty-six IPT patients were included and the average age was 52.3 years, and 57.7% were male and 42.3% were female. Most lesions were involved in the sinuses (88.5%) and the incidence of extension beyond the sinuses itself was as follows: the cheek/hard palate/parapharynx (15.4%), orbit (61.5%), skull base (57.7%), and dura or brain (23.1%). All IPT cases revealed IgG4 + plasma cells and IgG4/IgG ratio over 0.4 was detected in 42.3% (11/26) of cases. In case of SBO, no patients had IgG4/IgG ratio exceed 0.4. Main treatment modality was systemic steroids (61.5%) and other modalities were used: surgery (3.8%), immunosuppressant (7.7%), radiotherapy (30.8%), or a combination of these modalities (15.4%). Steroid responses were not significantly different, but IgG4-positive group tended to have better response to steroid therapy.

CONCLUSIONS

IgG4-positive and IgG4-negative IPT patients revealed no differences in involvement sites, clinical course, and steroid responses. However, IgG4/IgG ratio and IgG4 + plasma cell count can provide a diagnostic clue for infiltrative skull base lesions such as IPT and a differential diagnosis of SBO.

Inflammatory Pseudotumor of the Pancreas Mimicking a Pancreatic Neoplasm

A 78-year-old woman was admitted to our hospital with a pancreatic tumor, incidentally discovered in an abdominal ultrasound exam. She was asymptomatic and without any previous personal pathological condition. The computed tomography (CT) and the magnetic resonance imaging (MRI) scan showed a mass lesion of 4 cm in diameter, located in the pancreatic body, conditioning the invasion of the splenic vein. The patient was admitted to surgery. During the laparotomy, we found a tumoral lesion highly suspicious of pancreatic neoplasia located in the transition of the head/body of the pancreas, with an invasion of the portal vein and several peri-regional lymph nodes. We performed biopsies of the pancreatic mass and lymphadenectomy of the peri-regional pancreatic lymph nodes. Histological analysis found an inflammatory pseudotumor of the head/body of the pancreas, without signals of malign epithelial neoplasm and also without criteria for immunoglobulin G4-related disease. During the follow-up, a PET/CT and MRI confirmed that the pancreatic lesion had disappeared without any treatment. Inflammatory pseudotumor of the pancreas is a rare entity not fully understood. Despite this, the administration of corticosteroids and immunosuppressive therapy could be taken into consideration as the disease carries a risk.

Bilateral extraocular muscle enlargement and proptosis associated with squamous cell carcinoma of the lung

Thyroid-associated orbitopathy is characterised on cross-sectional imaging by symmetric extraocular muscle enlargement sparing the musculotendinous junction. We report a case of this imaging finding in a biochemically euthyroid patient with metastatic squamous cell carcinoma of the lung undiagnosed at time of presentation.

Spectrum of Pitfalls, Pseudolesions, and Misdiagnoses in Noncirrhotic Liver

OBJECTIVE

The purpose of this article is to illustrate the various pitfalls, mimics, and atypical features that can lead to inaccurate diagnosis of focal lesions in a noncirrhotic liver. The content includes relevant pathogenesis and background as well as specific clues that can be used to reach an accurate diagnosis.

CONCLUSION

When assessing focal hepatic lesions, it is important to avoid pitfalls and misdiagnoses that can alter the management plan. Helpful strategies for avoiding pitfalls include paying close attention to the clinical history of the patient, carefully evaluating all of the available imaging studies, and being aware of the various radiologic mimics.

Tumefactive fibroinflammatory lesion successfully treated with Rituximab

Skull base pseudotumors, or tumefactive fibroinflammatory lesions (TFIL), are tumors characterized by local destruction with benign histopathology. Treatment includes surgery and steroids with varying degrees of symptom relief. A 45-year-old female presented with right otorrhea and middle ear effusion, which progressed to CN V₃ pain/numbness, trismus, headache, and autophony. MRI showed a diffuse infiltrating mass in the right infratemporal region involving the trigeminal ganglion. Biopsy revealed benign fibromuscular and adipose tissue with lymphoplasmacytic infiltrate, giving a diagnosis of TFIL. Resection would be very difficult given tumor location. Initial treatment included an extended course of steroids without response, and interval disease progression. Two courses of rituximab 375 mg/m² weekly × 4 given 3 months apart were then completed with excellent tolerance. With sixteen months following induction, the patient reports minimal symptoms with radiographic findings confirming continued disease regression. Rituximab is a potential treatment option for patients with TFIL without response to steroids.

Inflammatory myofibroblastic tumour of the jaw: A rare presentation

Inflammatory Myofibroblastic Tumour (IMT) is a rare entity of unknown aetiology and pathogenesis. It was initially described in the lung, although there have been reported cases affecting extra-pulmonary sites. The aetiology of IMT remains unclear, with current evidence suggesting that IMTs are neoplastic processes resulting from chromosomal translocations that often cause an overexpression of ALK tyrosine kinase. Histologically, a variably cellular myxoid morphology is common in these tumours, with the presence of inflammatory cell infiltrate. Clinically, symptoms are non-specific, although the presence of a swelling is frequently reported. Imaging studies are not very useful in the diagnosis, as they only describe the presence of a mass, and do not provide a definitive diagnosis. This article presents a case, of Inflammatory Myofibroblastic Tumour of the jaw, in a male patient aged 16 years.

Paraduodenal inflammatory pseudotumor masquerading as malignancy

A 30-year-old woman presented with severe abdominal pain and abdominal distension. CT demonstrated two intra-abdominal masses, one involving the left lateral segment of the liver and the other adjacent to the duodenum. Initial biopsies were consistent with focal nodular hyperplasia of the liver and non-specific lymphocytic infiltrate in the paraduodenal mass. Due to persistent symptoms, the patient underwent laparoscopic resection of the paraduodenal mass. Final pathology was consistent with an inflammatory pseudotumour and the patient's symptoms subsequently resolved.

Uncommon Intraluminal Tumors of the Gallbladder and Biliary Tract: Spectrum of Imaging Appearances

Intraluminal pathologic conditions of the bile ducts and gallbladder are common, most frequently consisting of calculi and adenocarcinoma. In recent years, intraductal papillary neoplasm of the bile ducts (IPN-B), which is analogous to intraductal papillary mucinous neoplasm of the pancreas, has been recognized as a distinct pathologic entity and a precursor lesion to adenocarcinoma of the bile ducts. Intraductal tubulopapillary neoplasm (ITPN) of the bile duct was subsequently described as a distinct pathologic entity. With increased awareness and advances in imaging techniques, these lesions are diagnosed with increased frequency at preoperative imaging. A similar neoplasm in the gallbladder is referred to as intracholecystic papillary neoplasm. These lesions are often diagnosed at a preinvasive stage and have a better prognosis than invasive cholangiocarcinoma when treated with curative resection, underscoring the importance of an accurate imaging diagnosis. The most common causes of polypoid lesions of the gallbladder are cholesterol polyps and adenomyomatosis. These lesions need to be differentiated from the less common but clinically important adenocarcinoma of the gallbladder. Imaging is crucial to identify polyps that are at high risk for malignancy so that the appropriate management choice between imaging follow-up and cholecystectomy can be made by the treating physicians. Other less common gallbladder tumors, such as gallbladder adenomas, lymphoma, and metastases to the gallbladder, can manifest as intraluminal tumors; and awareness of these lesions is also important. In this article, the recent literature is reviewed; and the imaging appearances, histopathologic findings, and management of uncommon intraluminal tumors of the bile ducts and gallbladder and their mimics are discussed. ^©RSNA, 2019.

Primary Pulmonary Paraganglioma Revealed by FDG PET/CT

Primary pulmonary paraganglioma is a rare type of extra-adrenal paragangliomas arising from neuroectodermal-derived paraganglionic tissue. We report herein the case of a 49-year-old woman with a round-like well-defined nodule in the right middle lobe detected by chest CT. FDG PET/CT also revealed this homogeneous nodule with increased FDG accumulation. Finally, the patient underwent right middle lobe resection, and the pathological findings demonstrated the diagnosis of pulmonary paraganglioma.

ALK Negative Inflammatory Myofibroblastic Tumor Synchronous with Classical Hodgkin Lymphoma

Inflammatory myofibroblastic tumor or inflammatory pseudotumor was first described by Brunn in 1932. Umiker et al. named it so in 1954 for its ability to mimic malignancy clinically and radiologically [Med Pediatr Oncol 2000; 35(5): 484–7]. This tumor, characterized by its rareness, affects mainly the lung and the orbit. Histologically, the tumor is characterized by the presence of fibroblasts, myofibroblasts, polymorphs, lymphocytes, and neutrophils. This case report and review of literature present a male patient, 37 years old, with a bulky mediastinal lesion at the topography of the 4th rib. Histopathology reveals Hodgkin's Lymphoma (HL) concomitant with inflammatory myofibroblastic tumor (IMT). This report aims to emphasize the relevance of differential diagnoses to a better medical assistance. To the best of our knowledge, a case with this characteristic has never been seen before.

Intussusception secondary to inflammatory myofibroblastic tumor of the small intestine. Case report

Introduction: Intussusception occurs when part of the intestine slides into an adjacent intestinal segment. Inflammatory myofibroblast tumor is a rare cause of this condition, and is observed in 5% -16% cases in adults.Case presentation: A 41-year-old woman presented with abdominal pain and distension. A exploratory laparoscopy was performed, finding ileocolic intussusception into the transverse colon. Due to uncontrollable bleeding, the procedure was converted to laparotomy; resection and latero-lateral ileocolic anastomosis were performed. Histopathology reported inflammatory myofibroblastic tumor, with a favorable postoperative evolution. The patient was discharged on the sixth postoperative day.Discussion: When located in the small intestine, 57% of the tumors that cause intussusception are benign, including the myofibroblastic tumor in this patient. The symptoms and signs associated with this neoplasm are cramp-like abdominal pain, nausea and vomiting. Although imaging studies may lead to suspect this diagnosis, in most cases it is made intraoperatively. Surgical resection of the affected intestinal segment is curative, with favorable prognosis.Conclusions: This case is considered as a rare cause of intussusception. It had a benign course and is still under study since its pathophysiology has not been fully understood.

Retroodontoid Pseudotumor Related to Development of Myelopathy Secondary to Atlantoaxial Instability on Os Odontoideum

Retroodontoid pseudotumor (ROP) is a nonneoplasic lesion of unknown etiology, commonly associated with inflammatory conditions, and the term of pannus is usually used. Less frequently, ROP formation can develop with other noninflammatory entities, with atlantoaxial instability as most accepted pathophysiological mechanism for posttraumatic or degenerative ROP. As it can clinically and radiologically mimic a malignant tumor, it is paramount for the radiologist to know this entity. Magnetic resonance imaging is the modality of choice to reveal the possible severe complication of ROP in the form of a compressive myelopathy of the upper cervical cord. The purpose of the surgical treatment is the regression or complete disappearance of ROP, with posterior decompression by laminectomy and posterior C1-C2 or occipitocervical fixation. We present the case of an elderly patient with retroodontoid soft tissue mass secondary to a chronic atlantoaxial instability on os odontoideum, an extremely rare cause of ROP. The patient developed a posttraumatic cervical myelopathy related to the decompensation of this C1-C2 instability responsible for the formation of a compressive ROP. We will overview the retroodontoid pseudotumor and its differential diagnosis.

Inflammatory myofibroblastic tumor of the pleura with adjacent chest wall invasion and metastasis to the kidney: a case report

BACKGROUND

Inflammatory myofibroblastic tumor is a rare benign neoplasm that frequently involves the lung and abdominopelvic region, and is found mainly in children and young adults. Inflammatory myofibroblastic tumor tends to be locally invasive or recurrent, and rarely metastasizes.

CASE PRESENTATION

A 76-year-old Korean man presented with a history of upper back pain for 2 months and motor weakness in both lower extremities for 2 days. Contrast-enhanced computed tomography of his chest and abdomen showed a large heterogeneous pleural mass involving the right fifth rib and vertebral body and a mass infiltrating the right renal hilum. Computed tomography-guided percutaneous needle biopsy of the pleural mass was performed. The histological findings on hematoxylin and eosin staining showed proliferation of spindle cells with infiltration of lymphocytes and plasma cells. Immunohistochemistry showed neoplastic cells positive for CD68, focally positive for smooth muscle actin, and negative for cytokeratin and desmin. Inflammatory myofibroblastic tumor was diagnosed based on the histological examination. Treatment with glucocorticoids (methylprednisolone 1 mg/kg) and radiotherapy (5 days/week for 3 weeks at 3 Gy/fraction, 45 Gy/15 days) was started. After 1 month, chest computed tomography showed a reduction in the size of the pleural mass, and abdominopelvic computed tomography showed decreased infiltration around the right renal pelvis.

CONCLUSIONS

Inflammatory myofibroblastic tumor is a rare neoplasm of intermediate malignant potential due to a tendency for local recurrence and it rarely develops distant metastases. Complete surgical resection is the primary treatment. However, unresectable and metastatic inflammatory myofibroblastic tumor can be treated with systemic therapy, including glucocorticoids, radiotherapy, and/or chemotherapy.

Immunoglobulin G4 (IgG4)-Positive Ocular Adnexal Mucosa-Associated Lymphoid Tissue Lymphoma and Idiopathic Orbital Inflammation

PURPOSE

To report clinical and pathological characteristics of idiopathic orbital inflammation and ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma with immunoglobulin G4 (IgG4)-positive plasma cells.

METHODS

A retrospective histopathological review and clinical case series. A total of 51 biopsy samples from January 2005 to December 2015 were used in this study, including 21 cases of biopsy-confirmed idiopathic orbital inflammation and 30 cases of biopsy-confirmed ocular adnexal MALT lymphoma. Most cases of ocular adnexal lymphoma were conjunctival tissue. Retrospective immunohistochemical studies were performed to estimate the IgG4 and IgG4/IgG ratios. Histopathologic features, demographic and clinical data, radiologic findings, treatment, and follow-up information for each patient were analyzed.

RESULTS

Among idiopathic orbital inflammation, 6 (28.6%) of the 21 patients were diagnosed as "probable" ocular adnexal IgG4-related diseases and 13 (43.3%) of the 30 patients were diagnosed as MALT lymphoma with IgG4-positive plasma cells. Six cases of 13 IgG4-positive MALT lymphoma group had contralateral chronic inflammatory lesions infiltrated by IgG4-positive plasma cells, which was significantly (p = 0.007) higher than that in the IgG4-negative group. Conjunctival involvement was 69% of the IgG4-positive MALT lymphoma cases. Bilateral involvement of the ocular adnexa was significantly (p = 0.02) more frequent among IgG4-positive MALT lymphoma patients than that in IgG4-positive idiopathic orbital inflammation patients. Recurrence rate in the IgG4-positive group was higher (p = 0.05) than that in the IgG4-negative group but not significantly.

CONCLUSIONS

This study presented an unusual framework of ocular adnexal IgG4-related inflammation, in conjunctiva. It is important to understand contralateral chronic inflammatory lesions and their relationship with IgG4-positive MALT lymphoma. Tissue biopsy and IgG4 immunostaining are required for all cases because IgG4-positive MALT lymphoma can arise from a pre-existing IgG4-positive chronic inflammatory lesions. This is the first study that performs IgG4 immunostaining for tissue from a relatively large number of conjunctival MALT lymphomas in a single center. Therefore, it will help to diagnose conjunctival lymphoproliferative disease.

Mesenchymal Lesions of the Breast: What Radiologists Need to Know

OBJECTIVE

Mesenchymal breast tumors originate from the various components of mammary stroma. The aim of this review is to discuss the clinical presentation, imaging appearance, and management of mesenchymal breast lesions.

CONCLUSION

Although many mesenchymal tumors exhibit characteristic findings on imaging, others show nonspecific characteristics and require tissue biopsy for diagnosis. An awareness of the clinical and imaging presentation is essential in guiding the differential diagnosis and patient management.

Benign Sclerosing and Fibrosing Conditions of the Abdomen and Their Potential Mimics

The process of abnormal reparative or reactive processes in the abdominal cavity, can lead to sclerosis and fibrous deposition. The relatively recent discovery of an IgG4 subgroup of immune mediated sclerosing disease 1,2 has thrown some light on the pathophysiology of these conditions. Firstly, our pictorial review aims to describe imaging findings to enhance the general radiologist's recognition and interpretation of this varied group of benign sclerotic and fibrotic abdominal processes. Secondly, along with the imaging findings, we bring into discussion the potential mimics of these pathologic processes to minimise interpretational errors. Moreover, some of the mimics of these processes are in the spectrum of malignant disease. Most importantly, to ensure a correct diagnosis thorough clinical and histopathological assessment are required to support the imaging findings presented in this review.

The Clinical and Radiological Characteristics of Inflammatory Myofibroblastic Tumor Occurring at Unusual Sites

Inflammatory myofibroblastic tumor (IMT) can occur rarely in the soft tissue or joint of the limb. We retrospectively collected IMT cases of these rare sites and analyzed their clinical and imaging appearance. Thirteen cases of IMT were clinically diagnosed and underwent surgical procedures, pathological analyses, and postsurgical follow-up in our two hospitals. Other than one case of IMT of the bladder wall that presented with gross hematuria, none presented with local swelling, fever, or weakness. All the cases of IMT occurring at the bone showed destruction and parosteal soft tissue masses. The boundaries between the mass and normal bone were vague, without calcifications or any periosteal reaction. Five cases of IMF showed continuous enhancement on CT; seven cases demonstrated iso- or hyposignal intensity on T1WI; one case showed hypersignal intensity on T1WI, and eight cases demonstrated a hypersignal intensity signal on T2WI. All the masses located in soft tissues showed clear and sharp boundaries with different sizes of the swelling regions surrounding muscle interspaces. Three cases showed homogeneous enhancement, one case demonstrated heterogeneous enhancement, and two cases showed edge enhancement on enhanced MRI scans. On pathology, all the lesions showed an absence of a pseudocapsule, and four cases of ALK were positive. The radiological manifestations of IMT located at the soft tissue and bones were similar to benign tumors in shape; however, peritumoral edema, parosteal soft tissue, and the invasive rim of IMT are similar to the features of malignant tumors. Different radiological methods should be used to obtain an accurate diagnosis.