What do we know about inflammatory myofibroblastic tumors? - A systematic review

Inflammatory pseudotumor: big similarities and diagnostic challenges

Inflammatory pseudotumors are reactive and rare lesions of unknown origin. They are locally aggressive, but they generally do not extend beyond the affected organ, with a favorable prognosis after radical surgical resection. Symptoms and radiologic features are often nonspecific, and pathological examination plays a pivotal role in the diagnosis of inflammatory pseudotumors along with immunohistochemical staining to rule out differential diagnosis, especially myofibroblastic inflammatory tumor. Molecular biology can play a decisive role when these latter cannot establish a definitive diagnosis. Herein, we present a case study that describes a 65-year-old woman presenting a mesocolic mass. The patient underwent a surgical excision, which included a wedge gastric resection, transverse colectomy, and colocolic side-to-side stapled anastomosis. Histopathology and immunohistochemistry confirmed an inflammatory pseudotumor. Surgery remains the main treatment and depends on the location of the tumor. No recurrences are noted; however, a standardized follow-up protocol for inflammatory pseudotumors has yet to be established.

An Inflammatory Myofibroblastic Tumour Presenting with Limited Mouth-Opening, Hypoesthaesia of The Left Chin and Infraorbital Area, Intermittent Left Eye Ptosis and Converging Strabismus

An inflammatory myofibroblastic tumour (IMT) is a rare neoplasm of mesenchymal origin, defined by myofibroblastic spindle cells accompanied by inflammatory cells, lymphocytes and eosinophils. Its symptomatology depends on the involved site and tends to mimic a malignant tumour clinically and radiologically. The head and neck region accounts for 5% of all IMTs. Here, we report a case of a 35-year-old woman, with no medical history, who presented with a mouth-opening limitation of 8 mm evolving for three years and occurring six months after of a wisdom tooth extraction. She also experienced a recent occurrence of left eye ptosis and a converging strabismus. On examination, the patient had a body temperature at 37°C, with hypoesthaesia of the left chin and infraorbital area, without any other abnormality. Laboratory examinations did not reveal a biological inflammatory syndrome or rhabdomyolysis. The infectious investigations were all negative, as well as the immunological tests, in particular negative for anti-AChR and anti-MuSK antibodies. On the facial computed tomography (CT) scan, we noted an active reshuffle in the left mandible ascending branch with a thickening of the ipsilateral pterygoid muscles and the left temporal meningeal tissue. After corticosteroid therapy 0.7 mg/kg/j, we obtained an improvement in the patient's mouth-opening, thus a biopsy of the lesion was performed under local anaesthesia, revealing IMT. The patient continued the corticosteroids therapy with a progressive tapering resulting in a marked clinical improvement of the mouth-opening limitation and her ptosis.

LEARNING POINTS

An inflammatory myofibroblastic tumour (IMT) is a challenging disease.Given the variable clinical and radiological presentation of the disease, it is of paramount importance to know it, to be swiftly recognised so diagnosis can be promptly made.The adapted treatment should be immediately started to prevent possible life-threatening outcomes.

Inflammatory Myofibroblastic Tumor of the Lung: A Report of a Rare Case

The uncommon and mysterious pulmonary inflammatory myofibroblastic tumor (PIMT) primarily affects children and young people. PIMT is characterized by the proliferation of myofibroblastic spindle cells mixed with inflammatory cells. It can resemble both benign and malignant disorders, both radiographically and clinically. PIMT typically manifests as a solitary lung tumor. The genesis of the tumor is linked to genetic anomalies, including those related to the ALK gene (anaplastic lymphoma kinase); nonetheless, some cases are not ALK-positive, indicating genetic variability. Clinically, patients may have non-specific symptoms such as cough, chest pain, or hemoptysis, or they may not exhibit any symptoms at all. In these cases, imaging tests may unintentionally reveal unrelated conditions. From a histopathological perspective, PIMT is characterized by a heterogeneous cellular makeup, encompassing lymphocytes, myofibroblasts, plasma cells, and histiocytes, which generally exhibit a fascicular or storiform pattern. The diagnosis is verified using immunohistochemical labeling, molecular research, and histological examination. The cornerstone of treatment is still surgical resection, which has a good prognosis and a low recurrence rate. On the other hand, specific treatments, such as ALK inhibitors, have shown promise for incurable or recurring instances. Even though PIMT usually has a benign history, it is important to comprehend its biological behavior and molecular foundations for precise diagnosis and efficient management. This underscores the need for additional study into the pathophysiology and potential treatments of PIMT. This report presents a case of a 53-year-old female who presented with complaints of breathlessness and chest pain and was diagnosed with the condition accidentally.

Pediatric skull inflammatory myofibroblastic tumor: a rare case report and literature review

Inflammatory myofibroblastic tumors (IMTs) represent rare neoplasms, particularly infrequent in the pediatric skull. We present a novel case of a newborn male with a 5 cm right temporal mass and discuss current diagnostic and treatment options for IMTs. A multidisciplinary effort to surgically remove the lesion was successful, and the patient's skull defect healed without neurological deficits. The etiology of IMTs remains elusive, with proposed associations with chromosomal mutations in the anaplastic lymphoma kinase (ALK) gene. Surgical excision remains the primary treatment for IMTs. Promising pharmacological treatments, like Crizotinib, warrant further research into understanding potential alternatives in IMT management.

Inflammatory myofibroblastic tumor in the liver: a case report

Background

Hepatic inflammatory myofibroblastic tumor (IMT) is an infrequent tumor with potential malignancy. However, it lacks specific clinical symptoms and usual imaging features.

Case presentation

A 34-year-old woman had a six-month history of fever and on-and-off pain in the upper right part of her abdomen that lasted for two weeks. Imaging tests revealed a liver mass initially thought to be liver malignancy, but subsequent histopathological examination after liver removal confirmed the diagnosis as hepatocellular inflammatory myofibroblastic tumor (HIMT).

Conclusion

Hepatic inflammatory myofibroblastic tumor (IMT) is an uncommon growth with vague clinical symptoms and lab results. Surgical removal remains the primary treatment method, resulting in favorable prognostic outcomes.

Inflammatory myofibroblastic tumor of the cecum presenting as acute abdomen, a rare pathology with a rarer presentation

Inflammatory myofibroblastic tumor is an extremely rare neoplastic lesion with a predilection for aggressive local and recurrent behavior. The tumor tends to occur in the lungs of children and young adults, and although it can develop in older patients and other organs, this is extremely rare. Symptoms are nonspecific and depend on the location and size of the tumor. The gastrointestinal tract is rarely this mass's primary site of origin, and the cecum is an even rarer location. We present the case of an otherwise healthy 55-year-old female who presented with an acute abdomen and a mass in her abdomen; after successful surgery, she fully recovered. Inflammatory myofibroblastic tumor causing acute abdomen was the final diagnosis.

Inflammatory myofibroblastic tumor of the urinary bladder: A systematic review of the literature and report of a case

Introduction

Inflammatory myofibroblastic tumors (IMTs) are intermediate-grade lesions that frequently recur and rarely metastasize. There are currently no guidelines on the management of bladder IMTs. This systematic review aims to describe the clinical presentation and compare the management options for bladder IMTs.

Methods

A PubMed/Medline search was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using the following Mesh terms: ("inflammatory myofibroblastic") AND ("tumor") OR ("tumor") AND ("bladder") AND ("case report"). A total of 75 case reports were included in the analysis.

Results

The mean age of the patients was 36 years. 65% of the cases initially presented with hematuria. 68% of the tumors stained positive for anaplastic lymphoma kinase, and 20% invaded the muscularis. Patients underwent either transurethral resection of the bladder tumor (TURBT) only (34%), TURBT followed by complementary partial cystectomy (16%), or TURBT followed by radical cystectomy (4%). 36% and 9% of the cases underwent partial and radical cystectomy after the initial diagnosis, respectively. Cystectomies were performed using an open (74%), laparoscopic (14%), robotic-assisted (10%), or unknown (2%) approach. At a mean follow-up of 14 months, the recurrence and metastasis rates were about 9% and 4%, respectively. In addition, we present the case of a 49-year-old woman with a bladder IMT who underwent TURBT followed by laparoscopic partial cystectomy. The patient remains tumor free postoperatively (follow-up period of 12 months).

Conclusion

A complete surgical excision of the bladder IMT is crucial for the optimal management of these cases. Proper differentiation of this tumor from sarcoma or leiomyosarcoma leads to the best outcomes.

Endobronchial Inflammatory Myofibroblastic Tumour Masquerading as a Ruptured Hydatid Cyst

Inflammatory myofibroblastic tumours (IMTs) represent a rare group of neoplastic lesions characterized by a diverse clinical presentation. Endobronchial involvement is infrequently reported, and its manifestation mimicking the symptoms of a ruptured hydatid cyst adds an additional layer of complexity to the diagnostic challenge. This case report delves into an exceptional clinical scenario where an endobronchial IMT masqueraded as a ruptured hydatid cyst, initially confounding the diagnostic team. Through a detailed examination of the patient's clinical history, radiological imaging, bronchoscopy findings and subsequent histopathological analysis, we aim to contribute to the existing medical literature and shed light on the nuances encountered in accurately identifying and differentiating these two entities.

A rare huge bladder inflammatory myofibroblastic tumor treated by en bloc resection with diode laser: a case report and literature review

Background

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm with malignant potential. Bladder IMT is even rarer and mainly treated by surgical resection However, partial or radical cystectomy would affect the quality of life of patients due to major surgical trauma, and classical TURBT is hard to avoid intraoperative complications including obturator nerve reflex and bleeding etc. Therefore, the safe and effective better choice of surgical approaches become critical to bladder IMT.

Case presentation

A 42-year-old male patient was admitted to the department of urology with persistent painless gross hematuria for more than 10 days without the presentation of hypertension. Preoperative routine urine examination of red blood cells was 7738.9/HPF (normal range ≤ 3/HPF). CTU indicated a space occupying lesion (6.0 cm×5.0 cm) in the left posterior wall of the bladder with heterogeneous enhancement in the excretory phase. MRI also indicated bladder tumor with slightly equal SI on T1WI and mixed high SI on T2WI (6.0 cm×5.1cm×3.5cm) in the left posterior wall of the bladder. En bloc resection of bladder IMT with 1470 nm diode laser in combination of removing the enucleated tumor by the morcellator system was performed. Postoperative pathological examination revealed bladder IMT, with IHC positive for Ki-67 (15-20%), CK AE1/AE3, SMA, and Desmin of bladder IMT and negative for ALK of bladder IMT as well as FISH negative for ALK gene rearrangement. Second TUR with 1470 nm diode laser was performed within 6 weeks to reduce postoperative risk of recurrence due to highly malignant potential for the high expression of Ki-67 (15-20%) and negative ALK in IHC staining. The second postoperative pathology report showed chronic inflammation concomitant with edema of the bladder mucosa without bladder IMT, furthermore no tumor was observed in muscularis propria layer of bladder. No recurrence occurred during the period of 24-month follow-up.

Conclusion

En bloc resection of bladder IMT in combination of the following second transurethral resection with 1470 nm diode laser is a safe and effective surgical approach for the huge bladder IMT with highly malignant potential.

Unraveling the spectrum of inflammatory myofibroblastic tumors in the lung: A comprehensive case series highlighting endobronchial, pleural, and lung parenchymal tumors

Objectives

Diverse cases of inflammatory myofibroblastic tumors (IMTs) in the lung (pleural, endobronchial, and parenchymal) are presented while discussing the (preoperative) diagnostic challenges and treatment modalities. Other objectives include emphasizing the significance of gene rearrangements and highlighting the multidisciplinary approach in addressing IMTs.

Methods

Four cases of IMT in the lung are presented, including a young adolescent girl with an ETV6-neurotrophic tyrosine receptor kinase 3 (NTRK3) gene rearrangement, a 5-year-old boy with challenging preoperative diagnosis, and 2 middle-aged women with respectively pleural and endobronchial tumors with one peribronchial relapse.

Results

The cases demonstrate the diverse clinical presentations and diagnostic complexities associated with IMT in the lung. Surgical resection remains the primary treatment modality, with complete resection leading to a cure in most patients. Unfortunately, aggressive relapse can occur, as in our last case of an endobronchial tumor. Frozen section may confirm the presence of malignant cells perioperatively and impact further treatment. The presence of gene rearrangements, such as ETV6-NTRK3, suggests potential therapeutic implications.

Conclusions

Early detection and complete surgical removal of IMT are crucial for effective treatment. Identifying gene rearrangements such as ETV6-NTRK3 holds promise for targeted therapies. Diagnostic challenges, including the controversy of biopsies and preoperative evaluations, underscore the importance of a multidisciplinary approach. Anatomopathological recognition of IMT stays demanding. Close surveillance is necessary due to potential relapse, whereas frozen section perioperatively can help further treatment. This case series emphasizes the diagnostic challenges and therapeutic considerations for IMT in the lung.

Gastric and cardiac inflammatory myofibroblastic tumor: an extremely rare case

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a unique, rarely metastatic tumor composed of myofibroblasts and fibrous spindle cells with inflammatory cell infiltration that can affect any organ in the human body. By reviewing the relevant literature on PubMed, we found that this is the first case report of IMT with both gastric and cardiac involvement.

CASE PRESENTATION

A 57-year-old male patient was admitted to the hospital with complaints of malaise, poor appetite, and epigastric pain with black stools. We found a mass in the patient's stomach and left atrium by contrast-enhanced computed tomography, 18 F-fluorodeoxyglucose positron emission tomography/computed tomography, and other tests. The patient underwent laparoscopic Billroth II subtotal gastrectomy and Braun's gastrointestinal reconstruction under general anesthesia. On the 46th day following stomach surgery, the cardiac tumor was removed under general anesthesia. The patient has treated with doxorubicin 70 mg of D1 chemotherapy two months after cardiac surgery. Postoperative pathological immunohistochemistry of the mass confirmed the diagnosis of an IMT. His review three months after the cardiac surgery suggested the progression of the left atrial mass, but he declined further treatment and finally died one month after the review.

CONCLUSIONS

As a unique class of tumors that rarely metastasize, IMTs have an unknown etiology and pathogenesis, and distant metastasis is primarily observed in patients with negative activin receptor-like kinase (ALK) expression. The preferred treatment for IMT is complete surgical resection, and the effectiveness of adjuvant therapy for patients with distant metastases is still being determined. The clinical presentation of IMT lacks specificity and is often related to the location of tumor growth, which poses a diagnostic challenge. Pathological immunohistochemistry is the only way to confirm the diagnosis at present. Our case report reminds clinicians that a category of ALK-negative IMT with a tendency toward distant metastasis should not be ignored.

Uniportal video-assisted thoracoscopic fissureless right upper lobe anterior segmentectomy for inflammatory myofibroblastic tumor: A case report

BACKGROUND

Inflammatory myofibroblastic tumors (IMTs) are exceptionally rare neoplasms with intermediate malignant potential. Surgery is the accepted treatment option, aiming for complete resection with clear margins.

CASE SUMMARY

A 39-year-old woman presented with a growing solitary pulmonary nodule measuring 2.0 cm in the right upper lobe (RUL) of the lung. The patient under-went a RUL anterior segmentectomy using uniportal video-assisted thoracoscopy. A preliminary tissue diagnosis indicated malignancy; however, it was later revised to an IMTs. Due to the absence of a minor fissure between the right upper and middle lobes, an alternative resection approach was necessary. Therefore, we utilized indocyanine green injection to aid in delineating the intersegmental plane. Following an uneventful recovery, the patient was discharged on the third postoperative day. Thereafter, annual chest tomography scans were scheduled to monitor for potential local recurrence.

CONCLUSION

This case underscores the challenges in diagnosing and managing IMTs, showing the importance of accurate pathologic assessments and tailored surgical strategies.

An alternative spliced UPF2 transcript in pancreatic inflammatory myofibroblastic tumors

BACKGROUND

Inflammatory myofibroblastic tumors (IMTs) are characterized by myofibroblast proliferation and an inflammatory cell infiltrate. Our previous study on IMTs reveals that disrupt NMD pathway causes to lower the threshold for triggering the immune cell infiltration, thereby resulting in inappropriate immune activation. However, myofibroblast differentiation and proliferation is not yet known.

METHODS

RT-PCR, RT-qPCR, DNA sequence, western bolt, 5'race analysis and site-specific mutagenesis were used in this study.

RESULTS

Here, an alternative spliced (ALS) UPF2 mRNA skipping exon 2 and 3 and corresponding to the truncated UPF2 protein were found in 2 pancreatic IMTs. We showed that the uORF present in the 5'UTR of UPF2 mRNA is responsible for the translation inhibition, whiles ALS UPF2 is more facilitated to be translated into the truncated UPF2 protein. Several mRNA targets of the NMD were upregulated in IMT samples, indicating that the truncated UPF2 function is strongly perturbed, resulted in disrupted NMD pathway in IMTs. These upregulated NMD targets included cdkn1a expression and the generation of high levels of p21 (waf1/cip1), which may contribute to triggering IMTs.

CONCLUSION

The disrupt UPFs/NMD pathway may link to molecular alteration associated with differentiation and proliferation for IMTs.

Inflammatory myofibroblastic tumor of the upper arm: A case report

RATIONALE

Inflammatory myofibroblastic tumor (IMT) is an uncommon benign myofibroblastic tumor that usually occurs in the lung, mediastinum, abdomen and vulvovaginal region. IMT of the upper arm is exceedingly rare with unknown etiology. Pathology plays a major role in the diagnosis of IMT, and radiological characteristics of the condition are crucial for differential diagnosis.

PATIENT CONCERNS

A 62-year-old woman was admitted to our hospital for a complaint of a mass in her left upper limb with progressive numbness in the extremity. Ultrasound examination of the brachial artery (BA) revealed a hypoechoic mass with well-defined borders and a substantial blood flow, and the mass was also shown to be greatly enhanced on computed tomography (CT) and magnetic resonance imaging (MRI).

DIAGNOSIS

The subsequent histopathological and immunohistochemical studies led to the diagnosis of IMT.

INTERVENTION

The patient was referred for surgery. The soft tissue tumor resection, left median nerve release operation, brachial artery vascular grafting, and arterial anastomosis were performed.

OUTCOME

Favorable outcome was observed. The patient recovered well from the procedure and did not experience any further complications or tumor recurrence.

LESSONS

In this report, we describe a case of IMT of the upper arm with BA involvement. The case expands the differential diagnosis of limb neoplasm and broadens the understanding of its ultrasonic and radiological imaging features. It also serves as a further example of an uncommon region distinct from conventional IMT. Further studies on the etiology and therapeutic strategies are needed.

Infarction of Paratesticular Inflammatory Myofibroblastic Tumor Mimicking Testicular Torsion

This report describes a 14-year-old male with a rare paratesticular inflammatory myofibroblastic tumor that presented atypically with acute unilateral scrotal pain and swelling. This presentation, which raised suspicion for testicular torsion, contrasts with the typical presentation of a slow-growing scrotal mass. Scrotal exploration revealed an infarcted right testis, demonstrating this locally aggressive tumor can undergo vascular invasion and occlude testicular blood supply. Thus, inflammatory myofibroblastic tumor should be considered in the differential diagnosis when evaluating patients with acute scrotal pain suspicious for testicular infarction.

Update of Diagnosis and Targeted Therapy for ALK+ Inflammation Myofibroblastic Tumor

OPINION STATEMENT: Inflammatory myofibroblastic tumor (IMT), characterized by intermediate malignancy and a propensity for recurrence, has presented a formidable clinical challenge in diagnosis and treatment. Its pathological characteristics may resemble other neoplasms or reactive lesions, and the treatment was limited, taking chemotherapies as the only option for those inoperable. However, discovering anaplastic lymphoma kinase (ALK) protein expression in approximately 50% of IMT cases has shed light on a new diagnostic approach and application of targeted therapies. With the previous success of combating ALK+ non-small-cell lung cancers with ALK tyrosine kinase inhibitors (TKIs), crizotinib, a first-generation ALK-TKI, was officially approved by the U.S. Food and Drug Administration in 2020, to treat unresectable ALK+ IMT. After the approval of crizotinib, other ALK-TKIs, such as ceritinib, alectinib, brigatinib, and lorlatinib, have proven their efficacy on ALK+ IMT with sporadic case reports. The sequential treatments of targeted therapies in may provide the insight into the choice of ALK-TKIs in different lines of treatment for unresectable ALK+ IMT.

[Receptor tyrosine kinase- fusions in paediatric spindle cell tumors]

Pediatric spindle cell tumors are rare and often difficult to diagnose due to a similar morphology and a non-specific immunohistochemical profile. Genetic characterization of these lesions has been constantly improving, which has led to the identification of new subgroups that were partly included in the WHO classification. Receptor tyrosine kinase fusions play a special role in these tumors and their verification has diagnostic relevance and can be an option for target-oriented therapies. In the case of pediatric spindle cell tumors, genetic fusions form especially with NTRK1‑3, ALK, RET, and ROS1. Overall, pediatric tumors with receptor tyrosine kinase fusions are predominantly low-grade tumors, which are often subdivided into the group of intermediate-malign tumors.

Inflammatory myofibroblastic tumors: recent progress and future of targeted therapy

An inflammatory myofibroblastic tumor is a rare component of bone and soft-tissue sarcomas that has distinct pathological features as a lymphoplasmacytic inflammatory infiltrate. As is the case for other non-small round cell sarcomas, surgical resection remains the standard treatment strategy for inflammatory myofibroblastic tumors, but recurrence is possible. Concerning systemic therapy, the available data for conventional chemotherapy (such as those of doxorubicin-based regimens) are limited, and case reports of anti-inflammatory inflammatory myofibroblastic tumor treatments describe some degree of symptom relief and efficacy against tumor progression. However, as more information about cancer genomics accumulates, the potential for molecularly targeted therapies for inflammatory myofibroblastic tumors has become more promising. Approximately half of inflammatory myofibroblastic tumors harbor anaplastic lymphoma kinase (ALK) fusion genes, and the other half could have potentially targetable fusion genes or mutations such as ROS1, NTRK and RET; case reports demonstrating the clinical efficacy of treatments targeted to inflammatory myofibroblastic tumor have been published, as have several prospective clinical trials. Few drugs are approved for the treatment of inflammatory myofibroblastic tumor, and most of them were approved for tumor-agnostic indications. Drugs that could be used for pediatric indications and dosing in inflammatory myofibroblastic tumor have also not been established. To provide effective targeted therapy for rare diseases such as inflammatory myofibroblastic tumor, it is necessary to obtain clinical evidence by designing and performing clinical trials and to find a path toward regulatory approval.

Anaplastic Large-cell Lymphoma Involving Gastrointestinal Tract: A Clinicopathologic Study of 25 Cases of a Rare Tumor at a Rare Site

Background. Anaplastic large-cell lymphoma (ALCL) is an uncommon lymphoma divided into anaplastic lymphoma kinase (ALK) positive, ALK negative, and breast implant-associated (BIA) ALCL. Gastrointestinal tract involvement is very rare and may be difficult to diagnose. Its recognition is crucial as prognostic ramifications are different. Objectives. To describe clinicopathological features of ALCL involving the gastrointestinal tract. Materials and Methods. Slides were reviewed. Diagnosis was confirmed. Histological and immunohistochemical features were described. Results.Twenty-five tumors were diagnosed during the study period. Ages ranged from 14 to 65 years (mean 41 years). Mean age for ALK-negative and ALK-positive patients were 49 and 17 years, respectively. Twenty-one were males and 4 were females. Eighteen involved small intestine. Mean tumor size was 4.2 cm. All showed diffuse sheets of large anaplastic cells with pleomorphic nuclei, abundant pink cytoplasm, and strong positivity for CD30. Epithelial membrane antigen was positive in 17 tumors and keratin was negative in all. Eighteen tumors were ALK negative. Out of 14 patients with follow-up, 12 died within a few months of diagnosis. Seven had stage IE, 5 had stage IIE, and 2 had stage IV disease. Two patients were alive at 35 and 60 months. Twelve received chemotherapy. Conclusion. A marked male predominance was noted. Small intestine was the commonest site of involvement. Majority were ALK negative. ALK-negative tumors occurred in older patients and ALK positive in younger patients. Prognosis was poor. ALCL should be included in the differential diagnosis of anaplastic epithelioid cell neoplasms in the gastrointestinal tract.

Primary and secondary tumors of the peritoneum: key imaging features and differential diagnosis with surgical and pathological correlation

Peritoneal malignancies represent a diagnostic challenge for abdominal radiologists, oncologists, surgeons and pathologists in multidisciplinary teams, who must address their differential diagnosis, staging and treatment. In this article, we explain the pathophysiology of these processes and lay out the role of different imaging techniques in their evaluation. Then, we review the clinical and epidemiological aspects, the main radiological features and the therapeutic approaches for each primary and secondary peritoneal neoplasm, with surgical and pathological correlation. We further describe other rare peritoneal tumors of uncertain origin and a variety of entities that may mimic peritoneal malignancy. Finally, we summarize the key imaging findings of each peritoneal neoplasm to facilitate an accurate differential diagnosis that may impact patient management.Clinical relevance statementImaging plays an essential role in the evaluation of peritoneal malignancies, assessing their extension, detecting unfavorable sites of involvement and facilitating an accurate differential diagnosis, helping to choose the best therapeutic approach.

Hepatic inflammatory myofibroblastic tumor: A case report

BACKGROUND

Hepatic inflammatory myofibroblastic tumor (HIMT) is a rare type of hepatic tumor. It is always misdiagnosed and mistreated because it is primarily found with no obvious specific manifestation, and its imaging findings are diverse.

CASE SUMMARY

Here, we report a case of HIMT that was initially diagnosed as liver malignancy but was confirmed as HIMT by histopathology after hepatectomy. Mostly, HIMTs are infiltrated with plasma cells and stain positively for anaplastic lymphoma kinase on immunohistochemistry as well as for some other kinases.

CONCLUSION

HIMT can be treated with single nonsteroidal anti-inflammatory drugs and without surgery when it is diagnosed accurately. Because the etiology of HIMT is unknown and the diagnosis is difficult, the pathogenesis and clinical process need to be further studied.

Inflammatory Myofibroblastic Tumour of the Urinary Bladder in a Middle-Aged Man-A Case Report of an Unusual Localization of a Rare Tumour

Inflammatory myofibroblastic tumour (IMT) is a rare tumour with an intermediate biological behaviour. It usually occurs in children and adolescents, primarily in the abdomen or lungs. Histopathologically, IMT consists of spindle cells, i.e., myofibroblasts, and a variable inflammatory component. Localization in the urinary bladder is rare. We are presenting a rare case of IMT in the bladder in a middle-aged man treated by partial cystectomy. A 62-year-old man consulted a urologist because of haematuria and dysuric disturbances. A tumorous mass was detected by an ultrasound in the urinary bladder. CT urography described the tumorous mass at the dome of the urinary bladder measuring 2 × 5 cm. A smooth tumorous mass was cystoscopically observed at the dome of the urinary bladder. Transurethral resection of the bladder tumour was performed. Histopathological analysis of the specimen identified spindle cells with a mixed inflammatory infiltrate; immunohistochemical findings showed positivity for anaplastic lymphoma kinase (ALK), smooth muscle actin (SMA) and vimentin. A histopathological diagnosis of IMT was established. It was decided that the patient would undergo a partial cystectomy. A complete excision of the tumour from the dome of the urinary bladder with surrounding healthy tissue was performed. Histopathological and immunohistochemical findings of the sample confirmed the diagnosis of IMT, without the presence of the tumour at the surgical margins. The postoperative course went smoothly. IMT is a rare tumour in adults, especially localised in the urinary bladder. IMT of the urinary bladder is difficult to distinguish from urinary bladder malignancy both clinically and radiologically, as well as histopathologically. If the location and size of the tumour allow it, bladder-preserving surgeries such as partial cystectomy represent a reasonable modality of operative treatment.

Prevertebral Inflammatory Myofibroblastic Tumor Following COVID Vaccine Booster Dose

We report a case of a 30-year-old previously higid female presenting with dorsal pain and persistent fever after COVID-19 vaccine booster dose. CT and MR revealed a prevertebral heterogeneous and infiltrating mass, with spontaneous regression in control imaging which biopsy confirmed an inflammatory myofibroblastic tumor.

Inflammatory myofibroblastic tumour of the common bile duct: a case report and literature review

INTRODUCTION

Inflammatory myofibroblastic tumour (IMT) of the common bile duct (CBD) is an extremely rare low-grade malignancy with various biological behaviours and a lack of specific clinical and histopathological features. Preoperative and intraoperative diagnosis are challenging, and a diagnostic delay may increase surgical complexity.

CASE PRESENTATION

We present the case of a 34-year-old male with no relevant medical history who presented with jaundice of 20 days of evolution. Histology and immunohistochemistry confirmed the diagnosis of an IMT with anaplastic lymphoma kinase (ALK)-1 expression. In addition, a review of the relevant literature revealed 13 published reports of biliary IMTs. The clinical history and histopathological features in these 13 cases were compared with those in our case to provide a comprehensive overview of the clinical manifestations and histopathological features of the disease.

CONCLUSION

IMT of the CBD is an extremely rare low-grade malignancy that mainly occurs in middle-aged female patients. The main clinical manifestation is monosymptomatic jaundice. The reported tumours originated in the middle and lower segments of the CBD, with an average size of approximately 3.5 cm × 3.0 cm and tumour cells expressing smooth muscle actin (SMA), vimentin and ALK. Abnormal ALK expression and ALK gene rearrangement represent potential histopathological and differential diagnoses. A clear diagnosis by preoperative biopsy and intraoperative frozen section examination is critical and can significantly reduce surgical trauma. The prognosis is good, and very few patients experience recurrence or distant metastasis.

Inflammatory myofibroblastic tumor of the mesentery with a SQSTM1::ALK fusion responding to alectinib

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is an ultra-rare soft tissue neoplasm associated with fusion proteins encompassing the anaplastic lymphoma kinase (ALK) protein fused to a variety of partner proteins. Data regarding response to ALK-targeting agents based on fusion partner is limited.

CASE

A 30-year-old female sought emergency care after onset of abdominal and lower back pain in 2019. Computed tomography (CT) demonstrated a cystic, mesenteric mass within the pelvis measuring up to 8.9 cm. Complete laparoscopic excision of the mass from the mesentery of the right colon and terminal ileum was performed. Pathologic assessment revealed IMT with a fusion between sequestosome 1 and ALK (SQSTM1::ALK), described in only two other cases of IMT. Four months after surgery, CT revealed multi-focal, unresectable disease recurrence. She was referred to the University of Washington/Fred Hutchinson Cancer Center and placed on therapy with alectinib, after which she experienced a partial response. Three years after IMT recurrence, disease remains under control.

CONCLUSION

This is the third reported case of IMT associated with the novel SQSTM1::ALK fusion protein, and the second treated with alectinib. Treatment with the ALK inhibitor alectinib appears to be active in this setting.

Multifocal spinal inflammatory myofibroblastic tumors in a juvenile paraparetic dog

A 1-year-old, female English Bulldog presented with a 10-day history of progressive paraparesis. Neuroanatomical localization was consistent with T3-L3 segment myelopathy. Magnetic resonance imaging (MRI) revealed a severely compressive, mildly contrast enhancing, extradural, dorsal, broad-based mass at the level of L3-4. Similar, non-compressive, smaller nodules were present along the extradural space and dura mater of the caudal lumbar spine. Owners elected euthanasia based on these imaging findings and progressive clinical signs. Necropsy, histopathology and immunohistochemistry revealed a mesenchymal mass and nodules, admixed with numerous inflammatory cells. The diagnosis of an extradural inflammatory myofibroblastic tumor (IMT) with a multifocal presentation was made.

Treatment modalities of ALK-positive relapsed/refractory inflammatory myofibroblastic tumor of the brain and lungs in 7-year-old girl: case-based reviews

PURPOSE

Inflammatory myofibroblastic tumor (IMT) belongs to mesenchymal neoplasm of intermediate malignancy in WHO classification. Primary CNS disease or CNS metastases (CNS-IMT) occur in minority. We describe a case of relapsed/refractory IMT of lungs with multiple brain metastases in young child who achieved long-term complete response after alectinib. This systematic review also summarizes treatment modalities and outcome of children and adolescent with CNS-IMT.

METHODS

PRISMA 2020 guideline was applied to select an article from PubMed, Scopus, and Cochrane databases without time limits. This review focused on children and adolescent 0-24 years of age with CNS-IMT or inflammatory pseudotumor (CNS-IPT). The clinical characteristics and treatment outcome were explored.

RESULTS

A total of 51 patients in 49 publications were identified. Median age of patients with CNS-IMT/IPT was 15-year-old and 60.8% were male. The most common location of tumor was cerebral cortex (54.9%). Complete resection of CNS-IMT/IPT was performed in 27 cases with 100% complete response and 18.5% recurrence. Nearly half of patients who received partial resection without adjuvant therapy experienced progressive disease, while the contrast group totally achieved partial response. Overall responses in 7 patients treating with ALK inhibitors were 57.1% durable complete response and 42.9% transient partial response.

CONCLUSION

First-line treatment of CNS-IMT/IPT is complete resection. Patients who received partial tumor removal might have benefit from adjuvant therapy. ALK inhibitors reveal a promising result in unresectable CNS-IMT/IPT. Our case has shown a success in treating relapsed and refractory CNS-IMT as well as the primary site using 2nd-generation ALK inhibitor.

An extremely rare case of malignant jejunal mesenteric inflammatory myofibroblastic tumor in a 61-year-old male patient: A case report and literature review

Introduction

A mesenteric inflammatory myofibroblastic tumor (IMT) is a rare solid tumor of intermediate malignant potential that affects children, adolescents, and young adults predominantly. IMT is mostly encountered in the lung. We report a case of malignant jejunal mesenteric IMT in a 61-year-old male patient who presented with vague abdominal pain and generalized weakness. CT scan revealed a mesenteric mass displacing the attached jejunum. Surgical resection was curative.

Discussion

An extensive literature review was performed to update and further analyze the already available data. A total of 35 cases with mesenteric IMT were reported previously. Only five cases of jejunal mesenteric IMT were reported. Mesenteric IMT demands vast effort to reveal the diagnosis due to its vagueness in the clinical presentation. Mesenteric IMT resembles each other in plenty of pathological and immunohistochemical characteristics.

Conclusion

To the best of our knowledge, this is the first case of malignant jejunal mesenteric IMT in the elderly. Surgical resection was curative.

Recurrent uterine inflammatory myofibroblastic tumor previously managed as leiomyosarcoma has sustained response to alectinib

Soft tissue sarcomas encompass a wide range of histologic subtypes with varied clinical implications. The incorporation of comprehensive genetic profiling into clinical practice is refining our ability to make these distinctions in diagnosis to better reflect prognosis and clinical behavior of a tumor. In this report, we describe a case of recurrent inflammatory myofibroblastic tumor (IMT) of the uterus, initially diagnosed and managed as leiomyosarcoma. At the time of recurrence, the patient was found to have a TNS1-ALK rearrangement and was treated successfully with alectinib, a second-generation anaplastic lymphoma kinase (ALK)-inhibitor. She had a complete response by imaging six months after initiation of alectinib and remains without evidence of disease at 36 months follow-up. Pathology review in the setting of her known ALK fusion and the 2020 update to the World Health Organization Classification of Female Genital Tumors led to a change in diagnosis from leiomyosarcoma to IMT. Our case highlights the role of molecular testing in the diagnosis and management of uterine mesenchymal tumors and the efficacy of alectinib in this ALK-rearranged recurrent IMT of the uterus. Care must be taken to differentiate between IMT and other uterine mesenchymal tumors as this distinction can impact prognosis and management. Furthermore, this case adds to the growing body of evidence supporting the paradigm shift toward developing molecularly targeted therapies rather than disease site-specific treatments, especially in cases of recurrence as recommended by the National Comprehensive Cancer Network.

Clinicopathologic features and biologic behavior of canine splenic nodules with stromal, histiocytic and lymphoid components

The term fibrohistiocytic nodule has been discouraged in favor of specific pathologic entities, including complex nodular hyperplasia, splenic stromal sarcoma and histiocytic sarcoma. Nevertheless, the diagnosis of splenic lesions with mixed stromal, histiocytic and lymphoid components still remains a challenge due to lack of straightforward histologic criteria. Misestimation of the biologic behavior of these lesions may lead to detrimental consequences on the clinical management of patients. In this study, we retrospectively evaluated the clinicopathologic features and outcome of canine splenic nodular lesions with mixed components, to identify prognostic factors and histologic criteria of malignancy. Thirty-seven cases were included. Immunohistochemistry did not allow for further subclassification. Nine (24.3%) dogs died from disease-related causes after a median of 234 days (range, 48–1,247). One-, 2- and 3-year disease-specific survival rates were 80, 60, and 43%, respectively. When considering nodules with stromal cell atypia and at least one of mitotic count ≥9, presence of karyomegaly/multinucleated cells and lymphoid component <40%, half of these dogs died of disease-related causes with a median disease-specific survival time of 548 days (95% CI, 0-1216). In the remaining dogs, no disease-related death was reported (P < 0.001). Canine splenic nodular lesions with mixed stromal, histiocytic and lymphoid components and histologic criteria of malignancy may behave aggressively, leading to distant metastasis and death. In the absence of further criteria aiding their classification, and to better characterize their biologic behavior, we encourage the distinction of these complex splenic tumors from conventional sarcomas and histiocytic sarcomas.

Inflammatory Myofibroblastic Tumour: State of the Art

Simple Summary

Among sarcomas, which are rare cancers, inflammatory myofibroblastic tumors are extremely rare. Unlike other subtypes, this is a largely oncogene-driven neoplasia, and early gene rearrangement identification is important for accurate advanced stage treatment. In this manuscript, we review the clinicopathologic characteristics of this ultra-rare entity, as well as the current treatment landscape, with a particular focus on opportunities provided by tyrosine kinase inhibitors (TKIs).

Abstract

An inflammatory myofibroblastic tumor (IMT) is a neoplasm composed of myofibroblastic and fibroblastic spindle cells accompanied by inflammatory cells, including lymphocytes and eosinophils. It is an ultra-rare tumor, the optimal management of which remains to be defined. Surgery is the treatment of choice for localized tumors. The treatment of advanced disease is not precisely defined. Chemotherapy regimens result in an overall response rate of approximately 50% based on retrospective data. The latest pathophysiological data highlight the role played by tyrosine kinase fusion genes in IMT proliferation. Anaplast lymphoma kinase (ALK) oncogenic activation mechanisms have been characterized in approximately 80% of IMTs. In this context, data regarding targeted therapies are most important. The aims of this article are to review the latest published data on the use of systematic therapy, particularly the use of molecular targeted therapy, and to publish an additional case of an IMT with Ran-binding protein 2 (RANPB2)-ALK fusion showing a long response to a tyrosine kinase inhibitor.