Mesenteric inflammatory myofibroblastic tumor (IMT), a rare neoplasm in a pediatric patient: imaging findings and literature review

Inflammatory myofibroblastic tumors (IMTs) are rare neoplasms commonly classified as having "intermediate malignancy" due to their unique clinical, pathological, and molecular features. These tumors can exhibit aggressive biological behavior, including local invasion, recurrence, and, on rare occasions, distant metastasis. IMTs may arise in various anatomical locations, with the lung, mesentery, and omentum being the most frequent sites. Although IMTs can occur at any age, they are more commonly diagnosed in children and young adults. Their clinical manifestations and imaging findings are often nonspecific and may resemble malignant pathology, making diagnosis challenging. Moreover, the histopathological characteristics of IMTs can overlap with those of other conditions. In this report, we present a case of multicentric abdominal IMT in a pediatric patient and review the imaging features of abdominal IMTs in children, as documented in the limited number of available cases. Accurate differential diagnosis requires a comprehensive understanding of both the clinical presentation and radiographic features of these tumors. Radiologists should be familiar with the distinctive imaging characteristics of IMTs to ensure that this rare pathology is considered in the differential diagnosis of any abdominal mass in pediatric patients.

Inflammatory Myofibroblastic Tumor of the Esophagus and Stomach Successfully Treated With ALK Inhibitor in a Pediatric Patient: A Case Report and Concise Review of Literature

An inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal neoplasm of borderline malignant potential. Nearly half of all IMTs have rearrangement of anaplastic lymphoma kinase (ALK) locus on chromosome 2p23 which can be treated with targeted therapy. Herein, we describe an unusual presentation of IMT involving an anatomical region rarely implicated in this disease process. A 15-year-old male patient came to the ER with dysphagia and coffee ground emesis. On esophagogastroscopy, a nodular luminal obstructing 30 × 50 mm mass in the lower esophagus was found, which was continuous with a large, partially circumferential gastric mass extending from the mid-body to the proximal antrum. Biopsies from esophageal and gastric masses revealed submucosal lesions composed of cytologically bland spindle and epithelioid cells, intermingled with inflammatory infiltrate, for which several immunohistochemical (IHC) stains were performed. The molecular study demonstrated ATIC::ALK fusion. Based on morphological, IHC, and molecular study findings, the diagnosis of ALK-positive IMT was rendered. Because surgical excision was deemed infeasible, the patient was started on ALK-inhibiting therapy with crizotinib. The patient responded well with no evidence of residual or recurrent disease on follow-up imaging or surveillance esophagogastroduodenoscopy. Crizotinib was ultimately discontinued after 10 months of therapy, and the patient continues to undergo surveillance imaging for monitoring of disease burden.

Radiologic findings of an adolescent epithelioid inflammatory myofibroblastic sarcoma

Epithelioid inflammatory myofibroblastic sarcoma, a variant of the inflammatory myofibroblastic tumor, is a rare tumor that is not well described in the radiologic literature. We present a case of a 14-year-old male adolescent who presented with fever, fatigue, and weight loss symptoms and was found to have an abdominal mass on contrast enhanced CT. Initial differentials included lymphoma, pheochromocytoma, desmoid, and sarcoma, and pathological evaluation revealed an epithelioid inflammatory myofibroblastic sarcoma. The mass was separate from the surrounding structures of the left upper abdomen with unique radiologic features not previously described in the literature. Prior literature examples of epithelioid inflammatory myofibroblastic sarcoma described a heterogenous, enhancing lobulated mass, and our case was a lobulated, avidly enhancing homogenous mass on CT with surrounding inflammation and avid uptake on PET/CT. In addition to the imaging features, we describe the surgical findings, the pathologic features of the tumor, and the oncologic treatment of this patient. This case highlights the importance of including rare tumors such as epithelioid inflammatory myofibroblastic sarcoma as a potential differential consideration of an avidly enhancing homogenous abdominal mass in an adolescent.

Multimodality Imaging Features of Various Splenic Lesions: Clinical and Histopathologic Correlation

The spleen is occasionally referred to as the 'forgotten organ' because splenic lesions are less common and encountered rarely compared to pathologies of other abdominal solid organs. Therefore, although well-demonstrated using various abdominal imaging modalities, radiologists tend to be less familiar with splenic diseases, making interpretation challenging. This study aimed to review common and uncommon splenic diseases and illustrate the multimodal imaging (including ultrasonography, CT, MRI, and PET/CT) features of these lesions in correlation with their histopathology. Recognizing the radiological findings of various splenic lesions helps narrow down the differential diagnosis and guide appropriate clinical decision-making for radiologists.

An Interesting Case of Inflammatory Myofibroblastic Tumor Masquerading as Lymphoma Detected on 18F-FDG PET-CT

Inflammatory myofibroblastic tumors (IMT) are a rare set of tumors that have been reported in various areas of the body but not quite as often in systemic lymph nodes. Herein, we discuss the case of a 60-year-old woman who presented with bilateral cervical and axillary lymphadenopathy and a low-grade fever. She subsequently underwent a fluorine-18-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) as part of her evaluation. The scan revealed multiple hypermetabolic cervical, axillary, mediastinal, retroperitoneal, pelvic, and inguinal lymph nodes of various dimensions scattered throughout her body. Based on these findings, she was erroneously diagnosed to have lymphoma. It was only after histopathological correlation was the diagnosis revised to that of IMT, after which she was started on a course of oral corticosteroids. On follow-up imaging, she showed evidence of complete resolution of the involved lymph nodes. She has been disease-free for the past nine months after completing treatment. This case highlights the importance of including IMT as part of the differential diagnosis in suspected cases of lymphoma, giving credence to the phrase "all that glitters is not gold."

A Giant Solid-Cystic Gastric Inflammatory Myofibroblastic Tumor: A Case Report and Literature Review

An inflammatory myofibroblastic tumor (IMT) is a very rare tumor of mesenchymal origin with unclear etiopathogenesis, no unique diagnostic features, and no specific management protocol. It is often confused with inflammatory pseudotumor in literature, and the distinction needs further study. The average size, recurrence risk, and metastatic potential differ as per the site of origin. The abdomen is a very rare site for IMTs. Hepatic IMTs (H-IMTs) are reported to be solid tumors with sizes ranging from 1 cm to 20 cm in literature, and gastric IMTs (G-IMTs) range from 3 cm to 10 cm in size and can be solid-cystic. We report here a case of a 36-year-old gentleman with a 34x27x17 cm solid-cystic lesion in the lesser sac with loss of fat planes with stomach and left hemi-liver. The patient was managed by complete surgical resection of the lesion with wedge gastrectomy and wedge hepatectomy and recovered uneventfully. To our knowledge and based on our literature review, this case presents the largest reported and solid-cystic G-IMT with the involvement of left hemi-liver in a young gentleman and discusses its management as well as the relevant literature on this rare entity. This clinical presentation of G-IMT should be kept in the differential diagnosis in a relevant case presenting in the future. Immunohistochemistry is a must to establish the diagnosis, and surgical resection to negative margins is the management option of choice in resectable cases.

Liver transplantation for hilar inflammatory myofibroblastic tumor: Case report and review of the literature

BACKGROUND

Inflammatory myofibroblastic tumors (IMTs) of the liver are rare neoplasms. These tumors are difficult to distinguish from other neoplasms by radiological examination, have uncertain evolution, and there is no consensus on the treatment of these lesions. Hilar tumors can involve the portal vein, hepatic artery, bile duct, and spread to the branches of the portal triad, causing obstructive symptoms, occlusive phlebitis, and portal hypertension. Thus, liver transplantation (LT) is an excellent alternative for locally advanced hilar tumors, since it ensures complete tumor resection with free margins.

METHODS/RESULTS

We present a literature review and a case report showing a 3-year-old boy with liver IMT invading the hepatic hilum and inferior vena cava, who underwent a successful living donor liver transplantation that required portal vein and vena cava replacement.

CONCLUSION

The incidence of hilar IMTs is low and there is no well-established standard treatment. Liver transplantation for a hilar tumor with vascular invasion was acceptable in this case because the radically of the surgery was the key for the cure, and because the tumor was benign in nature.

Mesenchymal tumors of the stomach: radiologic and pathologic correlation

Mesenchymal tumors of the stomach are uncommon, with gastrointestinal stromal tumor (GIST) being the most common among them. Majority of the tumors may arise from cells of Cajal, smooth muscle cells, neural cells, totipotent stem cells, adipocytes or fibroblasts. Imaging plays an important role not only in staging but also in characterizing these tumors. Many of these tumors have characteristic imaging features. GISTs usually present as large cavitating and necrotic tumors with exophytic component. Presence of fat tissue within the tumor suggests a lipoma or a teratoma, early phase hyperenhancement indicates glomus tumor and hemangioma, and delayed contrast enhancement is seen in schwannoma. Their differentiation from epithelial tumors like carcinoma and neuroendocrine tumors is often possible based on the location (mesenchymal tumors are intramural), spread, morphological appearance and enhancement patterns. However, overlapping features exist between these tumors with imaging often being only suggestive. A biopsy is necessary for a definitive diagnosis in many cases.

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 tumours of the duodenopancreaticobiliary tract

Inflammatory myofibroblastic tumours (IMTs) are rare benign neoplasms of intermediate malignant potential that are found in the lungs and rarely at extrapulmonary sites common in children and young adults. IMTs tend to be locally invasive and have some amount of metastatic potential as well. We present two cases of IMTs involving the duodenum, pancreas and distal bile duct. The first case presented with extensive involvement of the first three parts of the duodenum and head of the pancreas, while the second presented with a pancreatic and biliary tree involvement. Upon examinations and investigations, these tumours mimicked malignant neoplasms. A Whipple procedure for surgical resection was undertaken in both cases. The histological findings showed fascicles of spindle cells with infiltration of lymphocytes and plasma cells. The inflammatory myofibroblastic tumour was diagnosed based on pathological grounds with immunohistochemistry. Preoperative diagnosis of IMTs is difficult and complete surgical resection is the primary treatment.

Recurrent infantile inflammatory myofibroblastic tumor of mesentery--Case report and review of imaging findings

Inflammatory myofibroblastic tumors (IMT) are rare soft tissue tumors of intermediate malignant potential with tendency for local recurrence. Although they can occur at all age groups, occurrence in infants is extremely unusual and their imaging characteristics are not well described. A 3-month-old female infant presented with gradually progressive abdominal distention without any fever or weight loss. She had a large ill-defined homogenous hypodense lesion of size 8.4 × 11.4 × 11.3 cm (APxTraxSag) in the abdomen showing mild delayed post contrast enhancement. She underwent exploratory laparotomy with gross total excision of mesenteric mass, histopathology of which was suggestive of IMT. She had recurrence within 6 months of complete resection with a well-defined heterogeneously enhancing lesion of size 1.8 × 1.8 × 2.3cm (APxTraxSag) in right paravesical region abutting the bladder without invasion with a similar lesion of size 4.4 × 2.1 × 3 cm (APxTraxSag) in left subdiaphragmatic region abutting superior surface of spleen (no invasion). Since, surgery in our patient would have entailed splenectomy and partial cystectomy, systemic therapy with ceritinib (anaplastic lymphoma kinase [ALK] inhibitor) was planned for her with which she had a near complete response after 2 months. A high index of suspicion is required to differentiate IMT from other common causes of mesenteric masses in children and role of radiologist is quintessential in this regard. Local recurrence with abutment but without invasion of surrounding structures points to the intermediate malignant pathology of IMT and may provide a clue to diagnosis. Systemic therapy is effective in patients who are ALK positive and destructive surgery should be avoided.

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.

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.

[Case of an Inflammatory Myofibroblastic Tumor of the Duodenum]

An inflammatory myofibroblastic tumor (IMT) is a rare disease that can occur in a variety of locations, including the lung, orbit, parotid, pleura, and stomach. Despite multiple reports in various organs, a duodenal IMT is rare with limited case reports. We encountered a case of a 49-year-old male with a duodenal IMT. The patient underwent a laparoscopic wedge resection under the impression of a duodenal mesenchymal tumor, such as gastrointestinal stromal tumor, but the final diagnosis was a duodenal IMT. The patient was treated successfully with an oral nonsteroidal anti-inflammatory drug for the residual lesions. He was free of recurrence during the 12 month follow-up period.

Computed Tomography and Magnetic Resonance Imaging Findings of Inflammatory Pseudotumors in the Abdomen and Pelvis: Current Concepts and Pictorial Review

The group of inflammatory pseudotumors (IPTs) encompasses a variety of rare neoplastic and nonneoplastic entities described to occur in almost every location in the body and whose clinical features and aggressive imaging findings (varying from infiltrative to mass-forming lesions), frequently mimic those of malignant tumors. The radiologic features of IPTs are variable and nonspecific, the imaging findings depending on the body location and involved organ. Abdominopelvic IPTs are rare and the purposes of this review, therefore, are to familiarize the radiologist with the wide spectrum of computed tomography and magnetic resonance imaging findings of IPTs in various locations throughout the abdomen and pelvis, discussing the imaging features that allow consideration of IPTs in the differential diagnosis of soft-tissue masses within the pertinent clinical setting. Radiologists should be aware of this group of entities, as a preoperative histopathologic diagnosis upon radiological suspicion may help to differentiate IPTs from malignancy and to allow the most appropriate clinical work-up for these patients.

Inflammatory myofibroblastic tumor of kidney together with ipsilateral perinephric and periureteric fibrosis: A case report and literature review

RATIONALE

Both inflammatory myofibroblastic tumor (IMT) and retroperitoneal fibrosis are rare lesions, but kidney involvement is more rare. It is the first study about IMT of the kidney in a patient with perinephric and periureteric fibrosis and we hold that fibroblast proliferation may be an intermediate status in oncogenesis of IMT. But further investigation is necessary in order to better clarify the relationship between fibroblast proliferation and IMT.

PATIENT CONCERNS

A 54-year-old female presented no positive signs except dull back pain after overwork.

DIAGNOSES

On the basis of the urinary ultrasonography and computed tomography (CT) scan, we strongly suspected a renal cell carcinoma.

INTERVENTIONS

Considering the little remaining function of the right kidney and the possibility of malignancy, we performed a laparoscopic right radical nephrectomy.

OUTCOMES

According to the analysis of the postoperative paraffin section and immunohistochemistry assay, a final diagnosis of IMT and retroperitoneal fibrosis nodules was made.

LESSONS

Both IMTs are rare lesions and its etiology and pathogeny are unclear. It is the first study about IMT of the kidney in a patient with perinephric and periureteric fibrosis. This report suggested that fibroblast proliferation may be an intermediate status in oncogenesis of IMT, but further investigation is necessary in order to better clarify the relationship between fibroblast proliferation and IMT. The preoperative diagnosis of renal IMT remains difficult. Preoperative fine-needle aspiration or percutaneous biopsy and intraoperative frozen section were applied to confirm the diagnosis to avoid unnecessary nephrectomy, especially in patients with renal insufficiency, bilateral masses, or a solitary kidney.

Imaging findings of inflammatory myofibroblastic tumor from the greater omentum: One case report

RATIONALE

Inflammatory myofibroblastic tumors (IMTs) are rare neoplastic lesions with benign tendency. Even more rare are IMTs from the greater omentum (GO-IMT). A GO-IMT is easily misdiagnosed as other malignant tumors before operation; thus, clinicians need to be familiar with its imaging findings. Here, we report the imaging findings of a GO-IMT patient presenting with a pelvic mass.

PATIENT CONCERNS

Ultrasound of the IMT in the pelvic cavity showed a hypoechoic mass. A computed tomography (CT) scan showed a nearly circular soft tissue mass with a clear border and heterogeneous density, and the surrounding tissues were pushed and compressed. Contrast-enhanced CT showed severe persistent enhancement in the lesion edges and mural nodules, but not in the central necrosis.

DIAGNOSES

Histopathology and immunohistochemistry confirmed that the mass was a GO-IMT.

INTERVENTIONS

The tumor was resected after preoperative preparation.

OUTCOMES

No recurrence or metastasis was found during a short-term follow-up.

LESSONS

The GO-IMT is an inferior epigastric mass in the periphery of the bowel, and is usually well-demarcated without calcification or lymphadenopathy. Contrast-enhanced CT showed a heterogeneous hypervascular mass where the center necrosis, the edge of the tumor, and the mural nodules can be partially reinforced.

Radiologic and Clinicopathologic Findings of Inflammatory Myofibroblastic Tumor

PURPOSE

The aim of the study was to describe the clinical, radiographic, and pathologic features of inflammatory myofibroblastic tumor (IMT) to enhance the recognition of this rare disease.

MATERIALS AND METHODS

The clinical, imaging, and pathologic findings were retrospectively reviewed in 54 patients with IMT lesions, which were conformed by biopsy or surgical pathology. Of 54 patients, 51 had preoperative computed tomography (CT) examination and 13 had preoperative magnetic resonance imaging records.

RESULTS

The clinical appearances of these 54 patients had some relationship with the locations of lesions. Of 54 IMT patients, 87.0% cases (47/54) had solitary lesion. The mean long diameter of the lesions located at the sites of chest, abdomen, and pelvic regions was bigger than that of other locations (F = 3.025, P = 0.038). On plain CT images, soft tissue mass was found in all IMT lesions, except for 3 lesions that arose in the intestine tract, appearing as focal or diffuse thickening in the bowel wall. After contrast administration, all lesions were persistently enhanced; 72.7% cases (24/33) demonstrated heterogeneous enhancement with various cystic regions. Comparing the CT features with different anatomic lesions, ill-defined margin on the plain CT images and calcification were seen more frequently in the lesions of the head and neck (P = 0.010 and 0.035); however, the other radiological findings had no significant differences (all P > 0.05). Twelve of 51 IMT patients showed invasion into adjacent structures. On magnetic resonance imaging, 92.3% lesions (12/13) showed soft tissue masses demonstrating isointense to hypointense contrast compared with skeletal muscle on T1-weighted images and heterogeneously high signals on T2-weighted images; 85.7%(6/7) of lesions were heterogeneously enhanced with cystic changes. Immunohistochemistry showed that the percentage of positive staining for SMA, vimentin, anaplastic lymphoma kinase, CD68, CD34, CD99, B-cell lymphoma/leukemia-2, cytokeratin, Desmin, and S-100 protein were 88.9%, 87.0%, 44.4%, 59.3%, 53.7%, 29.6%, 42.6%, 28.5%, 13.0%, and 24.1%, respectively.

CONCLUSIONS

Inflammatory myofibroblastic tumor can involve any part of the body, and the clinical and radiological appearances are various owing to different anatomic sites. An ill-defined soft tissue mass heterogeneous enhancement with or without invasion into adjacent structures on computed tomographic or magnetic resonance images and positive staining for SMA and vimentin on immunohistochemical examination could suggest the diagnosis.

Inflammatory myofibroblastic tumor involving liver, gallbladder, pylorus & duodenum: A rare case presentation

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Inflammatory myofibroblastic tumor, most common involvement is seen in the lungs, but in this case liver gallbladder, pylorus, 1st part of duodenum was involved.

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Most specific feature of IMTs, whose main cell type is myofibroblasts, is the ability to mimic malignancy.

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Surgery is the main treatment.

Inflammatory myofibroblastic tumors are rare benign tumors that can mimic malignancy of unknown aetiology. It has spectrum of myofibroblastic proliferation along with varying amount of inflammatory infiltrate. Recently, the concept of this lesion being reactive has been challenged based on the clinical demonstration of recurrences and metastasis and cytogenetic evidence of acquired clonal chromosomal abnormalities. We hereby report a case of inflammatory myofibroblastic tumor involving liver, gallbladder pylorus and 1st part of duodenum.

Retroperitoneal inflammatory myofibroblastic tumor: A case report

Inflammatory myofibroblastic tumors (IMT) were previously included in the “inflammatory pseudotumors” family, but have emerged as a distinct entity recently. The management of IMT may be challenging due to its intermediate malignant potential. We present a case of a young patient with an asymptomatic retroperitoneal mass with some imaging findings that could point to the IMT diagnosis pre-operatively. After two failed attempts to fully characterize the lesion by percutaneous and surgical biopsy, surgical resection was conducted and the final diagnosis was achieved.

Inflammatory myofibroblastic tumors of the duodenum

Inflammatory myofibroblastic tumors (IMTs) are rare soft-tissue tumors that can occur at virtually any anatomical site. We report the case of a 58-year-old male with an IMT of the fourth part of the duodenum who presented with signs and symptoms of high intestinal obstruction and bilious vomiting. The patient underwent a surgical resection of the fourth part of the duodenum with end-to-end duodenojejunal anastomosis. The follow-up period of 6 months was uneventful with no evidence of recurrence. According to our knowledge, only six cases of duodenal IMTs have been reported in the literature thus far, and this is the first report of a duodenal IMT sited at the fourth part of the duodenum. The duodenum is among the rarest sites of IMTs. Signs and symptoms resulting from diagnostic imaging investigations are nonspecific and inadequate to obtain diagnosis accurately. In most cases, surgical treatment is considered a cure for IMTs. There is no evidence of deaths caused by duodenal IMT. IMT of the duodenum is a possible diagnosis in differential diagnosis of tumor-like lesions of the duodenum.

Inflammatory Myofibroblastic Tumors: Current Update

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm of intermediate biological potential with a predilection for the lung and abdominopelvic region. IMT represents the neoplastic subset of the family of inflammatory pseudotumors, an umbrella term for spindle cell proliferations of uncertain histogenesis with a variable inflammatory component. IMTs show characteristic fasciitis-like, compact spindle cell and hypocellular fibrous histologic patterns and distinctive molecular features. Imaging findings reflect pathologic features and vary from an ill-defined, infiltrating lesion to a wellcircumscribed, soft tissue mass owing to variable inflammatory, stromal, and myofibroblastic components.

Inflammatory Myofibroblastic Tumor of Liver Masquerading as Focal Nodular Hyperplasia in a Patient with Non-Cirrhotic Portal Hypertension and Biliary Pancreatitis

Inflammatory myofibroblastic tumor (IMT) is a rare lesion of undetermined pathogenesis characterized by proliferation of spindled myofibroblast cells in a collagenized inflammatory background. It is usually benign but may show local infiltration or, in rare cases, metastasis. IMT has been observed in almost all solid organs; however, involvement of liver is exceptional. Its symptoms and radiological findings can mimic malignancy and pose diagnostic difficulties. The authors report the case of a 43-year-old woman with non-cirrhotic portal hypertension and gall stone induced acute pancreatitis having a mass in the right lobe of the liver which was initially diagnosed as focal nodular hyperplasia on imaging but proved to be inflammatory myofibroblastic tumor on pathological and immunohistochemical examination. The lesion resolved with conservative management without the need for surgical intervention.

Incomplete Intestinal Obstruction Caused by a Rare Epithelioid Inflammatory Myofibroblastic Sarcoma of the Colon: A Case Report

We reported on 1 case of epithelioid inflammatory myofibroblastic sarcoma (EIMS) that occurred in the colon and resulted in an incomplete intestinal obstruction.A 65-year-old male patient presented with abdominal pain without any obvious predisposing cause. He reported a paroxysmal dull pain. Hematochezia occurred occasionally. The symptoms appeared repeatedly and became progressively more aggravated. The patient sought medical advice in our hospital, and his enteroscopy showed colon tumors and an incomplete colonic obstruction. The laboratory examination indicated mild anemia. Plain and enhanced computed tomography (CT) scans showed a large, dumbbell-shaped, soft-tissue mass of 4.1 cm × 9.3 cm in the curved lumen of the descending colon near the spleen. After enhancement, the lesion presented with progressive and uneven enhancement. The boundary between the lesion and parts of the left kidney and spleen was obscured. A small amount of exudation was observed around the lumen, and a slightly enlarged lymph node shadow was observed in the mesangial gap.After each preoperative examination was completed, the tumors invading the spleen and left kidney were excised. Based on the surgical specimen pathological histology and immunohistochemistry, epithelioid inflammatory myofibroblastic sarcoma was diagnosed. Tumor recurrence occurred a short time after excision.EIMS in the abdominal cavity could occur on the intestinal wall, occasionally manifesting as large masses that expand to the inside and the outside of the cavity. It needs to be distinguished from other tumors. Tumor recurrence can easily occur after surgery. Anaplasticlymphoma kinase (ALK) inhibitors are a potential alternative treatment option.

Shedding light on inflammatory pseudotumor in children: spotlight on inflammatory myofibroblastic tumor

Inflammatory pseudotumor is a generic term used to designate a heterogeneous group of inflammatory mass-forming lesions histologically characterized by myofibroblastic proliferation with chronic inflammatory infiltrate. Inflammatory pseudotumor is multifactorial in etiology and generally benign, but it is often mistaken for malignancy given its aggressive appearance. It can occur throughout the body and is seen in all age groups. Inflammatory pseudotumor has been described in the literature by many organ-specific names, resulting in confusion. Recently within this generic category of inflammatory pseudotumor, inflammatory myofibroblastic tumor has emerged as a distinct entity and is now recognized as a fibroblastic/myofibroblastic neoplasm with intermediate biological potential and occurring mostly in children. We present interesting pediatric cases of inflammatory myofibroblastic tumors given this entity's tendency to occur in children. Familiarity and knowledge of the imaging features of inflammatory pseudotumor can help in making an accurate diagnosis, thereby avoiding unnecessary radical surgery.

MRI characterization of inflammatory myofibroblastic tumors in the maxillofacial region

PURPOSE

We aimed to investigate the magnetic resonance imaging (MRI) appearance of inflammatory myofibroblastic tumors (IMTs) in the maxillofacial region in order to improve diagnostic quality and resection efficacy.

MATERIALS AND METHODS

Ten cases of pathologically identified IMTs were analyzed by MRI. The MRI features were examined, including tumor location, tumor shape, tumor margins, and involvement of the surrounding tissues.

RESULTS

Of ten masses investigated in this study, eight masses were irregular neoplasms with unclear margins and two masses, in the parotid gland, were regular neoplasms with clear margins. Precontrast T1-weighted images of all ten masses exhibited isointense signals compared to the adjacent tissue, while contrast-enhanced T1-weighted images showed strong enhancement. Six masses were hypointense and four masses were slightly hyperintense in T2-weighted images. Involvement of the adjacent structures was observed in eight of ten cases. Meanwhile, two patients experienced intracranial involvement.

CONCLUSION

IMTs are rare tumors in the maxillofacial region, displaying a number of distinct MRI characteristics. Most importantly, they display low T2 signal intensity and strong enhancement, and they frequently invade surrounding structures. Thus, MRI can improve the accuracy of IMT diagnoses and provide critical information for surgical planning.

Imaging of childhood inflammatory myofibroblastic tumor

BACKGROUND

Inflammatory myofibroblastic tumor is a rare benign neoplasm and most commonly involves the lung but occurs in extrapulmonary locations.

OBJECTIVE

To present imaging findings in inflammatory myofibroblastic tumors in children based on a single-centre experience.

MATERIALS AND METHODS

We retrospectively reviewed CT and MRI findings of children diagnosed with inflammatory myofibroblastic tumor in a single institution.

RESULTS

We identified 15 children (range: 1-17 years) with inflammatory myofibroblastic tumor. The tumor was localized to the lung (n = 5), mediastinum (n = 3), trachea (n = 1), bronchus (n = 1), abdomen (n = 2) and orbit (n = 3). All the extraorbital tumors were solid masses with homogeneous or heterogeneous enhancement. Four lung tumors and one posterior mediastinal tumor contained calcification. Local recurrence following surgical removal occurred in two children with invasion of the esophagus and of the left atrium in one. Localized masses were seen in all children with orbital tumour. Two of these had episcleritis and perineuritis; one had episcleritis, tendonitis, perineuritis, myositis and dacryoadenitis.

CONCLUSION

The locations and imaging features of inflammatory myofibroblastic tumors are variable.

Imaging observations of pulmonary inflammatory myofibroblastic tumors in patients over 40 years old

Pulmonary inflammatory myofibroblastic tumors (PIMTs) are extremely rare in adults. If occurring in patients >40 years old, PIMT should be rapidly distinguished from lung cancer. The present study aimed to characterize the imaging features of PIMT in patients >40 years old in order to improve the diagnosis of PIMT. The imaging data of 10 patients with PIMT were reviewed retrospectively. Of the patients, eight underwent computed tomography (CT), two underwent positron emission tomography (PET)/CT and four underwent single-photon emission computed tomography (SPECT). Unenhanced CT revealed 10 lesions with a maximum diameter ranging between 5 and 57 mm located in the lower (n=6) or upper (n=4) lobe, in a peripheral (n=9) or central (n=1) region, and that were well- (n=4) or ill-defined (n=6), and round to oval (n=5) or irregular (n=5) in shape. Calcification (n=3), necrosis (n=6), cavity (n=4), air bronchogram (n=6) and obstructive pneumonia (n=1) were also observed in the patients. Contrast-enhanced CT revealed six lesions with moderate to high contrast enhancement in the arterial and venous phases, including four lesions with delayed enhancement. PET/CT identified two lesions with increased tracer uptake that were homogeneous and heterogeneous and each exhibited a maximal standard uptake value (SUV_max) of 6.0 and 5.4, respectively. The delayed PET/CT revealed foci that each exhibited an increased SUV_max of 6.9 and 5.9, respectively. SPECT demonstrated no definitive bone metastases, but did reveal atypical hypertrophic pulmonary osteoarthropathy in one patient. The combined imaging methods may lead to a more precise evaluation of PIMT in patients >40 years old.

Abdominal tuberculosis with periportal lymph node involvement mimicking pancreatic malignancy in an immunocompetent adolescent

Abdominal tuberculosis manifesting as isolated lymphadenopathy is rare, particularly in children. Tuberculous involvement of the pancreatic head and peripancreatic area can simulate a neoplasm of the pancreatic head. To our knowledge, obstructive jaundice caused by tuberculous lymphadenopathy has not been reported in children or adolescents. Here we present radiologic findings in a case of tuberculous lymphadenopathy that mimicked malignancy of the pancreatic head and caused obstructive jaundice in an immunocompetent adolescent.

Inflammatory myofibroblastic tumor: FDG PET/CT findings with pathologic correlation

PURPOSE

The aim of this study was to evaluate retrospectively F-FDG PET/CT findings of inflammatory myofibroblastic tumor (IMT) and their correlation with the pathologic findings.

PATIENTS AND METHODS

FDG PET/CT findings were reviewed in 5 patients with IMT and 1 patient with spindle cell sarcoma transformed from IMT. PET/CT scans were performed in all 6 patients before surgery. Follow-up FDG PET/CT scan was performed in 1 patient. The location, size, maximal standardized uptake value (SUVmax), and pathologic findings of the tumors were reviewed. The correlation between the FDG uptake and pathologic findings were analyzed.

RESULTS

A total of 10 lesions were detected in all 6 patients. The tumor locations were liver (n = 3), retroperitoneum (n = 2), spleen (n = 1), lung (n = 1), and bone (n = 3). Seven IMTs and 1 spindle cell sarcoma transformed from IMT were confirmed by pathology. The mean SUVmax of the pathologically proven tumors was 10.9 ± 5.5, with a high variability of SUVmax among tumors ranging from 3.3 to 20.8. The tumors (n = 7) with high cellularity had stronger FDG uptake, while the tumors (n = 1) with low cellularity had relatively low FDG uptake. The tumors with nuclear atypia and relatively high proliferative index had very strong FDG uptake, while those with low proliferative index or negative Ki-67 staining had relatively lower FDG uptake. One small tumor with abundant plasma cells showed high FDG uptake, while 1 large tumor with focal inflammatory cell infiltrate showed lower FDG uptake. One patient developed local recurrences and distant metastases revealed by the second FDG PET/CT scan 7 months after resection.

CONCLUSIONS

FDG uptake in IMTs varied from low to high FDG uptake, which may be due to tumor cellularity, biological behaviors of the tumor cells, the composition and the proportion of inflammatory cells, and the extent of activation of the inflammatory cells. FDG PET/CT may be useful for detection of the primary tumors, local recurrences, and distant metastases.

Two Cases of Infantile Intra-abdominal Inflammatory Myofibroblastic Tumor

Inflammatory myofibroblastic tumor (IMT) is rare mesenchymal solid tumor that consists of proliferating myofibroblasts with an inflammatory infiltrate background. It has a very low prevalence in infants and occurs mainly in children and young adults. IMT are mainly located in the thoracic cavity, but intra-abdominal lesions are rare. IMT can exhibit locally aggressive neoplastic processes and metastases similar to malignancies, so, have clinical importance. Herein, we describe two infantile intra-abdominal IMT cases presenting with incidentally found palpable abdominal mass. A 4-month-old male infant had IMT at the ileal mesentery and a 5-month-old male infant had IMT at liver. Both cases were successfully treated by complete surgical resection without complication or recurrence. Considering the biological behavior of the intermediate type of neoplasm in IMT, we expect good survivals when achieving appropriate surgical resection without adjuvant therapy in infantile intra-abdominal IMT.

A case of inflammatory myofibroblastic tumor originated from the greater omentum in young adult

Inflammatory myofibroblastic (IMF) tumor is a rare solid tumor that often affects children. IMF tumors occur primarily in the lung, but the tumor may affect any organ system with protean manifestations. A 22-year-old woman was evaluated for palpable low abdominal mass that had been increasing in size since two months prior. Abdominal computed tomography showed a lobulated, heterogeneous contrast enhancing soft tissue mass, 6.5 × 5.7 cm in size in the ileal mesentery. At surgery, the mass originated from the greater omentum laying in the pelvic cavity and was completely excised without tumor spillage. Histologically, the mass was a spindle cell lesion with severe atypism and some mitosis. Immunohistochemistry for anaplastic lymphoma kinase-1 revealed that the lesion was an IMF tumor. Because of its local invasiveness and its tendency to recur, this tumor can be confused with a soft tissue sarcoma. Increasing physician awareness of this entity should facilitate recognition of its clinical characteristics and laboratory findings.

Adult intussusception of the descending colon due to inflammatory myofibroblastic proliferation

We present a case of an asymptomatic 70-year-old man with intussusception of the descending colon due to inflammatory myofibroblastic proliferation. Abdominal ultrasound examination showed a hypoechoic mass, 32 × 19 mm in size, accompanied by intussusception in the descending colon, and power Doppler sonography detected blood flow signals in the mass. Computed tomography revealed a hypervascular lesion, which was confirmed by barium enema and colonoscopy. The surgically excised mass was histologically diagnosed as inflammatory myofibroblastic proliferation. Although intussusception due to inflammatory myofibroblastic proliferation is rare, it should be considered in cases of adult colonic intussusception.

Omental inflammatory myofibroblastic tumour mimicking peritoneal carcinomatosis

Inflammatory myofibroblastic tumour (IMFT) is a relatively uncommon neoplasm with unpredictable malignant potential known to occur anywhere in the body. IMFT involving the omentum is a very rare entity with less than 15 cases reported so far. We report a case of omental IMFT in a 15-year-old girl who presented with multiple peritoneal masses on imaging and the diagnosis was confirmed on histopathology. In addition to its uncommon location, its presentation as multiple masses is extremely uncommon. This uncommon presentation as multifocal masses needs to be distinguished from other causes of peritoneal carcinomatosis.

An inflammatory myofibroblastic tumor of the ampulla of vater successfully managed with endoscopic papillectomy: report of a case

Inflammatory myofibroblastic tumors (IMTs) are solid neoplastic mesenchymal proliferations composed of myofibroblastic spindle cells admixed with inflammatory infiltrates. The documented sites in the gastrointestinal tract include the esophagus, small intestine, colon, appendix, rectum, pancreas, spleen, liver, and Meckel's diverticulum. Biliary IMTs are rare, and IMTs arising from the ampulla of Vater have not been reported previously. Herein we report the case of a 65-year-old woman with an extrahepatic biliary obstruction due to IMT of the ampulla of Vater, and a successful therapeutic approach using endoscopic ultrasonography and endoscopic papillectomy.