Inflammatory myofibroblastic tumor of the central nervous system and its relationship to inflammatory pseudotumor

Inflammatory pseudotumor, the great mimicker: A case report

Inflammatory pseudotumor is a rare lesion, especially at the level of the central nervous system. Its etiology is unknown and the most accepted hypothesis is that it is the consequence of an exaggerated immune response. We present the clinical case of a young Senegalese male, with a history of epilepsy secondary to severe cranioencephalic trauma in childhood, who presented with new epileptic seizures. Imaging tests showed a lesion in the anterior fossa intimately attached to the meninges, so the initial diagnosis was meningioma. A bifrontal craniotomy and microsurgical excision were performed. The definitive anatomopathological analysis concluded that the lesion is an inflammatory pseudotumor whose origin is secondary to a disproportionate reparative process after cranioencephalic trauma.

Anaplastic Lymphoma Kinase (ALK) in Posterior Cranial Fossa Tumors: A Scoping Review of Diagnostic, Prognostic, and Therapeutic Perspectives

Anaplastic Lymphoma Kinase (ALK) has been implicated in several human cancers. This review aims at mapping the available literature on the involvement of ALK in non-glial tumors localized in the posterior cranial fossa and at identifying diagnostic, prognostic, and therapeutic considerations. Following the PRISMA-ScR guidelines, studies were included if they investigated ALK's role in primary CNS, non-glial tumors located in the posterior cranial fossa. A total of 210 manuscripts were selected for full-text review and 16 finally met the inclusion criteria. The review included 55 cases of primary, intracranial neoplasms with ALK genetic alterations and/or protein expression, located in the posterior fossa, comprising of medulloblastoma, anaplastic large-cell lymphoma, histiocytosis, inflammatory myofibroblastic tumors, and intracranial myxoid mesenchymal tumors. ALK pathology was investigated via immunohistochemistry or genetic analysis. Several studies provided evidence for potential diagnostic and prognostic value for ALK assessment as well as therapeutic efficacy in its targeting. The available findings on ALK in posterior fossa tumors are limited. Nevertheless, previous findings suggest that ALK assessment is of diagnostic and prognostic value in medulloblastoma (WNT-activated). Interestingly, a substantial proportion of ALK-positive/altered CNS histiocytoses thus far identified have been localized in the posterior fossa. The therapeutic potential of ALK inhibition in histiocytosis warrants further investigation.

Ocular inflammatory myofibroblastic tumor in a pediatric patient

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm that rarely metastasizes and is more commonly seen in children, adolescents, and young adults than older adults. These tumors, composed of myofibroblasts and inflammatory cells, are often confused for a local infection due to the inflammatory cell infiltration, and they form in mucosal surfaces but rarely arise in the orbit. We present the case of a 6-year-old girl with excisional biopsy-confirmed conjunctival stromal IMT. There was no evidence of recurrence 2 years following resection with no subsequent medical therapy.

Corticodependent and recurrent inflammatory pseudo tumor. Analysis of cases and review

Inflammatory pseudo tumor (IP) is an infrequent process with benign evolution in most cases whose etiology and pathogenesis are unknown. It usually affects young men and children, in whom the macroscopic lesion can mimic a malignant process, which is ruled out after biopsy. Therefore, the diagnosis of certainty is histological and treatment consists of corticosteroids, leaving resection for cases in which biopsy is not possible or in which it produces local complications. We present a case of an inflammatory pseudo tumor with special corticodependence that began as a long-term periodic fever and splenic focal lesion that required splenectomy for its diagnosis and that, after decreasing the corticosteroid regimen, presented recurrences at the cerebellar and systemic level requiring the association of various immunosuppressants and rituximab to achieve remission. As a result of this case, we have performed an analysis of all the pseudo tumors diagnosed in adults in the hospitals of the province of Malaga, and it has been compared with that described in the bibliography.

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.

Multiple inflammatory pseudotumor formation after craniopharyngioma resection via an extended nasal endoscopic approach: A case report

BACKGROUND

This report describes a case of intracranial multiple inflammatory pseudotumors (IP) after endoscopic resection of a craniopharyngioma, which is relatively rarely reported in the literature, and neurosurgeons should be aware of its existence.

CASE SUMMARY

Herein, we report the case of a 56-year-old man who developed decreased visual acuity and blurred vision without obvious cause or inducement on April 27, 2020. To seek further treatment, he went to the Department of Neurosurgery, Clinical Medical College, Yangzhou University. After falling ill, there was no nausea, vomiting, limb convulsions, obvious disturbance of consciousness, speech disorders, cough, or persistent fever. The neurological examination findings were normal, and pituitary magnetic resonance imaging (MRI) revealed multiple nodules with abnormal signals in the sellar region. The diagnosis was craniopharyngioma. We performed total resection of the tumor via transnasal endoscopy, and the postoperative pathology suggested that the type of tumor was craniopharyngioma. Six months after the operation, the patient experienced sudden hearing loss in the right ear, tinnitus in both ears, and numbness on the right side of the face and head. Meanwhile, cranial MRI showed multiple IP. After steroid hormone and anti-inflammatory therapy, the above symptoms did not significantly improve. Finally, the patient's symptoms were well improved by surgery, and the postoperative pathological diagnosis was multiple IP.

CONCLUSION

Intracranial inflammatory pseudotumor is a benign disease with slow progression, but the clinical symptoms and imaging findings are not typical, there are no pathological findings, and the diagnosis is relatively difficult. Most of the cases are treated by surgical resection, and the prognosis is good after surgery.

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.

Inflammatory myofibroblastic tumor of the central nervous system: A case report

BACKGROUND

An inflammatory myofibroblastic tumor (IMT) occurring in the central nervous system is very rare, and thus its pathogenesis is unknown. This case report and literature review aimed to explore the pathogenesis, clinical features, imaging findings, pathological characteristics, immunohistochemical characteristics, diagnoses, treatments, and risks of postoperative recurrence of IMT in the central nervous system.

CASE SUMMARY

A 67-year-old woman was admitted to the hospital with an exophthalmic protrusion and double vision in the left eye that had persisted for 3 mo. Magnetic resonance imaging (MRI) showed a 2.4 cm × 1.3 cm heterogeneous large mass in the bottom of the left anterior cranial fossa, which was closely related to the dura mater. Before surgery, we suspected the mass to be meningioma. The entire mass was successfully removed under neuronavigation and electrophysiological monitoring, and postoperative pathology indicated an IMT with extensive infiltration of chronic inflammatory cells and scattered multinucleated giant cells. Head MRI at the 3-mo follow-up showed that the tumor at the bottom of left anterior cranial fossa had been completely resected without recurrence.

CONCLUSION

From the histological, immunohistochemical, and genetic analyses, the present case suggests that the pathogenesis of IMT-CNS is related to autoimmunity.

Advanced MRI features of intraventricular inflammatory myofibroblastic tumor: a case report

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a rare central nervous system (CNS) tumor. We first report a rare case of IMT in the lateral ventricle and describe the magnetic resonance imaging (MRI) findings of the tumor with an emphasis on the advanced MRI features.

CASE PRESENTATION

A 49-year-old female patient with headaches and blurred vision for 2 months. Brain MRI revealed a well-circumscribed, lobulated mass occupying the left lateral ventricle trigone, with marked perilesional brain edema. The tumor showed heterogeneous significant hyperintensity on T2-weighted imaging (T2WI) and hypointensity on T1-weighted imaging (T1WI). After the administration of gadolinium, the mass exhibited marked contrast enhancement and the halo sign was observed. On advanced MRI, the lesion showed decreased perfusion on perfusion MRI and reduced diffusion on diffusion-weighted imaging (DWI). On susceptibility-weighted imaging (SWI), there was a punctate low signal intensity in the tumor. The patient underwent surgical resection of the mass and a pathological examination confirmed the lesion to be an inflammatory myofibroblastic tumor with negative expression of anaplastic lymphoma kinase (ALK). This patient had remained healthy without evidence of recurrence during a 20-month follow-up.

CONCLUSIONS

On MRI, marked perilesional brain edema, significant hyperintensity on T2WI, hypoperfusion on perfusion MRI but with an obvious enhancement, no diffusion restriction on DWI, and halo sign may be the characteristic findings of intraventricular IMT. The advanced MRI characteristics could provide abundant information to reflect the histological features and physiological metabolic characteristics of the tumor.

Cutaneous Inflammatory Myofibroblastic Tumor with CARS-ALK Fusion: Case Report and Literature Review

Cutaneous inflammatory myofibroblastic tumors (IMT) constitute a rare entity, generating a diagnostic pitfall when diagnosing spindle cell proliferation within the dermis. Raising awareness of this tumor among dermatopathologists remains vital in differentiating it from common cutaneous tumors such as fibrous histiocytoma, atypical fibroxanthoma, melanoma, poorly differentiated carcinoma, and other more aggressive tumors. Accurate diagnosis of IMT aid in ensuring appropriate management and follow-up for patients while preventing unnecessary harm and overtreatment. Here we report a case of a 38-year-old female with a painless, slow-growing nodule of the left posterior scalp initially diagnosed as a dermatofibroma. The histological examination revealed an ill-defined dermal nodule of spindled cells without connection or infiltration of the epidermis. At high power, the cells were arranged in fascicles with a prominent background of lymphocytic infiltrate. Immunohistochemical analysis showed strong diffuse immunoreactivity for anaplastic lymphoma kinase (ALK), targeted RNA sequencing identified a CARS-ALK fusion ultimately confirming the accurate diagnosis of a cutaneous IMT. This article is protected by copyright. All rights reserved.

Embryonal and non-meningothelial mesenchymal tumors of the central nervous system - Advances in diagnosis and prognostication

The 5th edition of the WHO Classification of Tumours of the Central Nervous System introduces new entities, and provides updated guidance regarding the diagnostic criteria for tumors of the central nervous system (CNS). CNS embryonal tumors and CNS non‐meningothelial mesenchymal tumors can be challenging for practicing pathologists, as the histologic features are not always specific to a particular entity, and integration of microscopic and molecular findings is necessary. This review on CNS embryonal and non‐meningothelial mesenchymal tumors is meant to provide an update with a focus on WHO changes and additions and on recent discoveries with diagnostic, prognostic, and therapeutic implications.

Inflammatory myo-fibroblastic tumor of appendix: A rare clinical entity

Introduction

Inflammatory myo-fibroblastic tumor of appendix is one of the rarest clinical findings and less has been described in the literatures. So, we aimed to present the clinical case that we encountered at our institute.

Presentation of a case

A 29-year-old lady presented with history of pain at the periumbilical area for one day which shifted to right iliac fossa. Clinical examination revealed tenderness and rebound at right iliac fossa with increased total leucocyte count and ultrasonography abdomen showed swollen appendix. Intraoperatively, a lump around 4 × 3 cm was evident at the tip of appendix with cut section revealing pus along with fecalith. Appendectomy was done with no spillage of the content within the peritoneal cavity. Histopathology revealed inflammatory myo-fibroblastic tumor of appendix. Patient is on regular follow up.

Discussion

Inflammatory myo-fibroblastic tumor of appendix is one of the rarest clinical findings that mimics malignancy. Presentation could be that of acute appendicitis and in most instances, diagnosis is made intraoperatively. Surgical removal is the mainstay of treatment with regular follow up of the patient for chances of recurrences. Histologically, edematous stroma consisting of inflammatory infiltrates composed of lymphocytes, plasma cells, eosinophils and focal formation of lymphoid follicles along with the proliferation of scattered spindle to ovoid cells with proliferating blood vessels with unremarkable over lying epithelium is evident. Myo-fibroblastic origin can be confirmed by immunostaining with smooth muscle specific vimentin and actin.

Conclusion

Inflammatory myo-fibroblastic tumor of appendix can present with features of acute appendicitis and may mimic malignancy. Appendectomy with regular follow up is mandated if such clinical cases are encountered.

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Inflammatory myo-fibroblastic tumor is a pseudo sarcomatous condition

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Appendiceal involvement is pretty rare.

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Clinical presentation may mimic that of acute appendicitis.

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Surgical removal and regular follow up are the main stay of treatment.

DCTN1-ALK gene fusion in inflammatory myofibroblastic tumor (IMT) of the CNS

PURPOSE

Inflammatory myofibroblastic tumor (IMT) is a rare neoplastic tumor type of intermediate biological potential, only recently distinguished from the non-neoplastic category of inflammatory pseudotumor (IP). The literature describes very few cases of IMTs arising in the central nervous system (CNS), and the distinguishing clinical, pathological, and molecular features of IMT-CNS are not well understood. Our purpose is to publish a case of an IMT-CNS with a novel DCTN1-ALK gene fusion, furthering in the literature's characterization of a rare tumor type.

METHODS

Review of the literature included a PubMed Database search of articles found by the following searches: "Inflammatory myofibroblastic tumor;" "Inflammatory myofibroblastic tumor central nervous system;" "ALK gene fusion;" and "DCTN1-ALK gene fusion." Inclusion of articles discovered by these search terms was determined through critical appraisal of article relevance, number of citations, cross-citation within articles of interest, and rare findings with conflicting conclusions in an effort to reduce publication bias.

RESULTS

We present a case of IMT-CNS with several distinctive molecular features including a DCTN1-ALK gene fusion, the first of its kind described in an intracranial IMT.

CONCLUSION

IMT is an infrequent tumor type and its presentation within the CNS is exceedingly rare. The paucity of cases, along with the ambiguity of terminology in the literature, has stunted accurate clinical, pathological, and molecular characterization of IMT-CNS. Our case report improves the characterization of the recently appreciated category of IMT-CNS so that connections between phenotype and prognosis, and between genotype and treatment, can eventually be made.

Inflammatory myofibroblastic tumor masquerading as an anterior choroidal artery fusiform aneurysm

Background:

Inflammatory myofibroblastic tumor is a rare, poorly understood tumor that has been found to occur in almost every organ tissue. Its location within the central nervous system is uncommon, and patients tend to present with nonspecific symptoms.

Case Description:

A female in her eighth decade presented to neurosurgery clinic with complaints of headache and dizziness. Initial imaging was consistent with a low-grade, benign brain lesion in the region of the left choroidal fissure. She was recommended for observation but returned 1 month later with progressive symptoms and doubling of the lesion size. She underwent surgical resection and was found to have an IMT arising from the wall of the left anterior choroidal artery.

Conclusion:

Intracranial IMT remains a rare and poorly understood entity. The present case demonstrates a novel presentation of IMT in an adult patient and exemplifies the heterogeneity of the disease presentation.

Clinical characteristics and prognosis of pulmonary inflammatory myofibroblastic tumor: An over 10-year retrospective analysis

Importance

Pulmonary inflammatory myofibroblastic tumors (PIMTs) are primary lung tumors in children. Misdiagnosis easily occurs because of the nonspecific clinical manifestations, laboratory examination results, and imaging findings in affected patients.

Objective

To summarize the clinical characteristics, diagnosis, and prognosis of children with PIMTs.

Methods

This retrospective analysis included 23 children with PIMTs who received treatment in our hospital from January 2008 to January 2019. The clinical manifestations, laboratory examination results, and computed tomography findings were retrospectively analyzed.

Results

The population included 13 boys and 10 girls, with a median age at onset of 78 months (range, 10–126 months). Fourteen patients had PIMT lesions in the right lung and nine patients had PIMT lesions in the left lung. The surgical procedures included pulmonary wedge resection, pulmonary lobectomy, and total pneumonectomy. The median operation time was 115 min (range, 45–235 min); the median intraoperative blood loss volume was 30 mL (range, 3–500 mL). During the operation, one patient each had pulmonary hemorrhage, vena cava hemorrhage, and thoracic duct injury. Postoperative complications included pulmonary embolism in one patient and tumor recurrence in two patients; neither of these complications recurred after reoperation. The median follow‐up period was 49 months (range, 2–127 months).

Interpretation

Children with PIMTs exhibited good prognoses and primarily underwent surgical resection as treatment. Complete preoperative evaluation should be performed in affected patients.

Infantile inflammatory myofibroblastic tumors: clinicopathological and molecular characterization of 12 cases

Inflammatory myofibroblastic tumors arising in infants are rare, poorly investigated and mostly reported as isolated cases or as a part of larger series thus, their clinicopathological and molecular features are essentially unknown. Archival files from two large pediatric institutions and a tumor registry were queried for pediatric inflammatory myofibroblastic tumors. Available material from patients ≤12 months of age was reviewed. Additional immunostains (ALK-1, D240, WT1) and ALK-FISH studies were performed as needed. Targeted anchored multiplex PCR with next-generation sequencing was done in all cases. A total of 12 of 131 infantile cases (mean 5.5 months) were identified (M:F of 2:1). Anatomic locations included intestinal/mesenteric (n = 6), head/neck (n = 3), and viscera (n = 3). Half of tumors showed a hypocellular myxoid pattern, perivascular condensation, and prominent vasculature with vague glomeruloid structures present in four of them. The remaining cases exhibited a more cellular pattern with minimal myxoid component. ALK-1 immunohistochemistry was positive in most cases (11/12) with cytoplasmic-diffuse (n = 6), cytoplasmic-granular (n = 2), and dot-like (n = 3) staining patterns. ALK fusion partners identified in five cases included EML4, TPM4, RANBP2, and a novel KLC1. Three inflammatory myofibroblastic tumors showed fusions with other kinases including TFG-ROS1 and novel FN1-ROS1 and RBPMS-NTRK3 rearrangements. Favorable outcome was documented in most cases (10/11) with available follow-up (median 17 months) while three patients were successfully treated with crizotinib. In summary, infantile inflammatory myofibroblastic tumors are rare and can exhibit paucicellular, extensively myxoid/vascular morphology with peculiar immunophenotype mimicking other mesenchymal or vascular lesions. All tumors harbored kinase fusions involving ALK, ROS1, and NTRK3 including three novel fusion partners (KLC1, FN1, and RBPMS, respectively). A favorable response to crizotinib seen in three cases supports its potential use in infants as seen in older patients. Awareness of these unusual morphologic, immunophenotypic, and molecular features is critical for appropriate diagnosis and optimized targeted therapy.

Intracranial Inflammatory Myofibroblastic Tumor with Negative Expression of Anaplastic Lymphoma Kinase: A Case Report and Review of the Literature

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is an indolent tumor mainly affecting children and young adults. As a rare mesenchymal tumor with unknown etiology and pathogenesis, IMT has a predilection for the lung and abdominopelvic region. Previous literature featuring IMT in the central nervous system (IMT-CNS) is rare. The clinical symptoms and radiologic features of IMT-CNS are not specific; therefore, the diagnosis is predominately based on the histopathologic and immunohistochemical analysis of the specimen.

CASE DESCRIPTION

We herein present a case of a 21-year-old woman who complained of bilateral blurred vision for 15 days. Head magnetic resonance imaging demonstrated a round-shaped and irregular lesion located in the right frontal lobe. The boundary of the lesion was clear, and the lesion was homogeneously enhanced. Peripheral edema of the lesion was observed, and the mass effect was obvious. Supratentorial craniotomy tumor resection was performed. Histopathologic and immunohistochemical analysis revealed IMT, which had negative expression of anaplastic lymphoma kinase.

CONCLUSIONS

Remission of her symptoms was observed, and no recurrence was recorded during a 6-month follow-up.

Inflammatory Myofibroblastic Tumor of the Tongue. Report of a Pediatric Case and Review of the Literature

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is an uncommon mesenchymal lesion composed of myofibroblastic and fibroblastic spindle cells, accompanied by inflammatory infiltration. IMT may occur in the tongue. Five cases have been previously reported at this site.

CASE REPORT

An inflammatory myofibroblastic tumor arose in the tongue of a 10 month old infant, confirmed by anaplastic lymphoma kinase (ALK) immunohistochemical staining and the clinical response to the tyrosine kinase inhibitor.

CONCLUSIONS

IMT can occur in the tongue. This report highlights the differential diagnosis of IMT. ALK staining is both a helpful diagnostic marker and a predictive marker for targeted therapy in this tumor type.

A Rare Case of Inflammatory Myofibroblastic Tumor of Meninges

Inflammatory myofibroblastic tumor (IMT) of the central nervous system is a rare entity of unknown etiology and a diagnostic dilemma for radiologists. We report a case of meningeal IMT occurring in a 15-year-old boy. Magnetic resonance imaging showed a large homogeneously enhancing extra-axial mass in left parietal region. Mass was resected en bloc and histopathological examination revealed the lesion to be composed of plasma cells, lymphocytes admixed with histiocytes, and spindle cells without any atypical cells, characteristic of IMT. This case emphasizes the need to consider IMT in the differential diagnosis of tumorlike intracranial meningeal lesions.

Intra-abdominal inflammatory myofibroblastic tumour (IMT) mimicking gonadal mass in a male infant with undescended testes

Inflammatory myofibroblastic tumour (IMT) is a rare benign neoplastic tumour, originally described as an inflammatory pseudotumor. Only a single case of IMT in the spermatic cord associated with undescended testes has been reported. We present a rare case of abdominal IMT in a male infant with undescended bilateral testes. The abdominopelvic mass was suspected to be a gonadal malignancy due to empty scrotal sac but proved to be otherwise on histopathology. Mass was completely resected and orchiopexy was performed for both undescended normal-appearing testes. The patient developed a recurrent mass 2 months later involving the left spermatic cord and the left testicle. Radical surgery was performed with removal of the left testicle and spermatic cord. The patient was disease-free at 1-year follow-up.

[Giant inflammatory pseudotumor of the cranial base]

The inflammatory pseudotumour (IPT) is a non-neoplastic entity of unknown origin, and is characterised by a proliferation of connective tissue and a polyclonal inflammatory infiltrate. Central nervous system involvement is uncommon, and usually represents a diagnostic and therapeutic challenge even for the experienced clinician. This reports deals with the case of a 56year-old woman diagnosed with a giant, infiltrating mass centred in the left cavernous sinus, who had a rapid clinical and radiological response to steroid therapy. Biopsy specimens were diagnostic for IPT. The progression of a small orbital residual lesion was detected after steroid withdrawal. Treatment with cyclophosphamide induced a complete response that remains stable after six years of follow-up.

Inflammatory Myofibroblastic Tumor of Common Bile Duct in a Girl

Inflammatory myofibroblastic tumor (IMT) is a rare, low grade malignant lesion which can occur anywhere in the body. In children it is usually found in the visceral soft tissues with a potential for local invasion and recurrence, and rarely distant metastasis. We report the diagnostic dilemma faced in the management of a 12-year old girl who presented with obstructive jaundice with a mass lesion at the distal end of the common bile duct. She underwent a tumor resection with a bilio-enteric bypass followed by a course of oral steroids and celecoxib.

Inflammatory pseudotumor of the pineal region: First reported case

Inflammatory pseudotumors originating in the central nervous system (CNS) are quite rare. To the best of our knowledge, the present study reports the first case of a inflammatory pseudotumor that developed in the pineal region, and describes the neuroimaging, morphological and immunohistochemical findings. A 53-year-old male presented with hearing loss that had been apparent for 1 year and blurred vision that had persisted for 10 months. Magnetic resonance imaging (MRI) demonstrated a homogeneously-enhanced mass in the pineal region and obstructive hydrocephalus. A pathological examination revealed that the lesion was comprised predominantly of spindled cells in a collagenous background, with dense infiltrates of small lymphocytes, plasma cells and uninucleated histiocytes. Immunopositivity for cluster of differentiation (CD)138 was noted. Immunohistochemical staining showed that the cells were immunonegative for glial fibrillary acidic protein, S-100, placental alkaline phosphatase, neurofilament and Pit-Oct-Unc class 5 homeobox 1. The Ki-67 labeling index was <5%. The lymphocytic infiltrates consisted of CD3- and CD43-positive T-cells, and CD20- and CD79A-positive B-cells. Plasma cells displayed polytypic reactivity for immunoglobulin κ and λ light chains. Based on the MRI and the morphological and immunohistochemical analysis, a diagnosis of an inflammatory pseudotumor was formed. The patient underwent a surgical resection of the tumor and currently has a good prognosis.

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.

IMAGING DIAGNOSIS - MAGNETIC RESONANCE IMAGING OF INTRACRANIAL INFLAMMATORY FIBROSARCOMA IN A MIXED BREED DOG

An 8-year-old mixed-breed dog presented with progressive behavioral changes and altered mentation. Magnetic resonance imaging (MRI) of the brain revealed an olfactory and frontal lobe extra-axial mass. The mass exhibited the following MRI signal intensity characteristics: T2W mixed, T1W iso- to hypointense, FLAIR hyperintense, and strong contrast enhancement. The mass was removed with cavitronic ultrasonic surgical aspirator (CUSA) assisted neurosurgery. Based on histopathological appearance and immunohistochemistry, the diagnosis of inflammatory fibrosarcoma was made. To our knowledge, this is the first report describing MRI characteristics of intracranial inflammatory fibrosarcoma in the veterinary literature.

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.

Inflammatory myofibroblastic tumor of the upper alveolus: A rare entity presenting as a jaw swelling

Inflammatory myofibroblastic tumor (IMT) is a rare tumor of borderline nature that can clinically present as a malignant neoplasm. It commonly occurs in the lungs, and a very few oral IMTs have been reported in the literature. IMT consists of inflammatory cells and myofibroblastic spindle cells. The diagnosis of IMT requires histopathological examination with immunohistochemical staining to look for the expression of smooth-muscle actin for confirmation of the diagnosis. The objective of this paper is to report an IMT on the upper alveolus with clinic-a pathological similarity with a malignant lesion and its management. Though oral IMTs are rare, it should be considered in the differential diagnosis of tumors of the upper jaw. Complete surgical excision of alveolar IMT is the treatment of choice because of its unpredictable clinical behavior. The patients with oral IMTs require periodic post-surgical follow-up for recurrence.

Sigmoid sinus occlusion infiltrated by inflammatory myofibroblastic tumor from mastoid

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) and some types of immunoglobulin (Ig) G4-related disease are often involved in the spectrum of inflammatory pseudotumor (IPT) and the concept of IgG4-related IPT/IMT has recently been proposed.

METHODS

A 38-year-old man complained of initial symptoms of blurred vision and headache.

RESULTS

A tumor was found in the right mastoid, which caused occlusion of the right sigmoid sinus and intracranial hypertension. A diagnosis of IMT with IgG4+ plasma cell infiltration was established by surgical, pathological, and immunohistochemistry findings. His symptoms were completely relieved after corticosteroid therapy and no recurrence was detected during 22 months of follow-up.

CONCLUSION

A case with cerebral venous sinus infiltrated by IMTs in the head and neck has never been reported; corticosteroid therapy proved satisfactory in IMT with IgG4+ plasma cell infiltration.

Inflammatory myofibroblastic tumors of the central nervous system that express anaplastic lymphoma kinase have a high recurrence rate

Background:

Inflammatory myofibroblastic tumors (IMTs) of the central nervous system (CNS) are rare entities with diverse histopathological features and varying propensities to recur.

Case Description:

A 26 year-old male with an IMT of the CNS of the left tentorium had tumor progression 2 months after partial surgical resection. Histopathological studies confirmed expression of ALK. Macroscopic total resection was performed followed by radiotherapy. A recurrence occurred 20 months after the second surgery that necessitate reoperation. Including the present case, we identified 30 cases of IMT of the CNS corresponding to our search criteria in the literature. The extent of resection was reported in 26 of these cases. Gross total resection was done in 75% of ALK-positive and in 61% of ALK-negative cases. Recurrence rate after gross total resection for ALK-positive and ALK-negative cases was 33% and 9%, respectively. Every recurrence in ALK-positive patients occurred within 2 years after surgery.

Conclusion:

IMT of the CNS are a heterogeneous group of tumors and the treatment of choice is complete surgical resection. Because of the high recurrence rate reported for IMT of the CNS expressing ALK, a closed follow-up is recommended. When faced with an early recurrence, a surgical resection followed by radiotherapy may be advised.

Inflammatory myofibroblastic tumor of the lung in children: anaplastic lymphoma kinase (ALK) expression and clinico-pathological correlation

The inflammatory myofibroblastic tumor (IMT) is a rare neoplastic lesion with a high incidence in children and young people, and may arise in lungs, soft tissue, or viscera. It is recognized as a borderline tumor with the possibility to recur, undergo malignant transformation, and metastasize. IMT is composed of fascicles of bland myofibroblastic cells admixed with an inflammatory infiltrate consisting of lymphocytes, plasma cells, and eosinophils. We reviewed pulmonary IMT diagnosed at Garrahan Hospital in Buenos Aires, Argentina, during 12 years and examined the clinical, laboratory, and pathological features as well as molecular genetics. Eight pediatric cases were evaluated with a male-to-female ratio of 5:3 and a median age of 6 years at diagnosis. The most common lung localization was the upper lobe. All cases underwent surgical excision and no local recurrences were found. Five out of eight patients, including two cases with metastatic/multifocal lesions in the central nervous system (CNS), are alive and disease free after a median follow-up of 30 months. Anaplastic lymphoma kinase (ALK) expression was negative in all pulmonary samples by immunohistochemistry (IHC), however, rearrangement for ALK locus by fluorescence in situ hybridization was found in one lung and in two CNS samples. These findings may reflect higher sensitivity of the molecular biologic procedure compare to traditional IHC practice. In our pediatric experience, 25% of patients with lung IMT developed CNS lesions; therefore we consider that CNS screening in these patients should be considered, at diagnosis and later during follow up.

IgG4-related inflammatory pseudotumor of the central nervous system responsive to mycophenolate mofetil

Orbital apex and skull base masses often present with neuro-ophthalmic signs and symptoms. Though the localization of these syndromes and visualization of the responsible lesion on imaging is typically straightforward, definitive diagnosis usually relies on biopsy. Immunohistochemistry is important for categorization and treatment planning. IgG4-related disease is emerging as a pathologically defined inflammatory process that can occur in multiple organ systems. We present two patients with extensive inflammatory mass lesions of the central nervous system with immunohistochemistry positive for IgG4 and negative for ALK-1 as examples of meningeal based IgG4-related inflammatory pseudotumors. In both patients, there was treatment response to mycophenolate mofetil.

The latest on IgG4-RD: a rapidly emerging disease

PURPOSE OF REVIEW

Provide an update of the developments in IgG4 related disease within the last year in terms of nomenclature, diagnostic criteria and clinical features.

RECENT FINDINGS

The number of diseases associated with IgG4 related disease continues to grow. The entities of idiopathic orbital inflammation, idiopathic cervical fibrosis, eosinophilic angiocentric fibrosis, reactive nodular fibrous pseudotumor, sclerosing mesenteritis, and membranous glomerulonephritis should all be added to the list of diseases associated with the IgG4 related disease spectrum. The issues of nomenclature and diagnostic criteria for IgG4 related disease have important recent developments as well.

SUMMARY

The diagnosis of IgG4 related disease continues to be challenging. Increasing recognition of IgG4 related disease has led to a large body of literature on organ sites of involvement. Understanding how the disease manifests itself is critical to diagnosis and ultimately treatment.

TLR4, IL-6, IL-18, MyD88 and HMGB1 are highly expressed in intracranial inflammatory lesions and the IgG4/IgG ratio correlates with TLR4 and IL-6

We determined distribution of plasma cells and IgG4/IgG index and factors associated with the index in intracranial inflammatory lesions. Specimens of nine patients were analyzed immunohistochemically using antibodies against CD45, CD68, CD3, CD4, CD8, CD20, CD138, lambda chain, kappa chain, IgG, IgG4, IL-1α, IL-6, IL-18, toll-like receptor (TLR) 2, TLR4, high-mobility group box 1 (HMGB1), tumor necrosis factor-alpha (TNF-α), myeloid differentiation factor 88 (MyD88), and anaplastic lymphoma kinase (ALK). The relationship between all the factors was assessed using Spearman's rank correlation coefficient (ρ). Negative ALK staining was observed in all the patients. Plasma cells were detected in eight patients with varying degrees. The highest number of neutrophils, but no plasma cells, was observed in a patient with the shortest history of inflammation. IgG4/IgG index was independent of the number of plasma cells. The index was relatively highly correlated with IL-6 (ρ = 0.7271) and TLR4 expression (ρ = 0.7246). IL-6 expression was highly correlated with TLR4 expression (ρ = 0.8042). IL-18 was maximally expressed in all the patients. TLR4 expression was strong, but TRL2 expression was weak. Positive HMGB1 staining was observed in all the patients, predominantly in the nuclei, but also in the cytoplasm in four patients. The cytoplasmic expression strongly correlated with IL-1α expression (ρ = 0.9583). The cytoplasmic colocalization of HMGB1 and IL-1α was histologically confirmed in cells with collapsing nuclei by the double-staining method. The IgG4/IgG indexes varied case by case. IL-6 and TLR4 expressions may influence IgG4/IgG index. The nuclei of cells with both IL-1α and HMGB1 expressions in the cytoplasm collapse in the cell death stage. The cooperative high expression of TLR4, IL-6, IL-18, MyD88 and HMGB1 suggest their critical roles in the inflammation circuit.

Plasma Cell Granuloma of the Thyroid Gland

This study reports a case of plasma cell granuloma of the thyroid gland in a 47-year-old woman, presenting with a right subhyoid mass and a previous diagnosis of Hashimoto thyroiditis dating back to 1988, which was made on a subtotal thyroidectomy. Plasma cell granuloma preferentially involves the lung, with only 18 cases of thyroid gland involvement having been reported to date in the English literature. Thyroid plasma cell granuloma preferentially affects women and classically shows a prominent plasma cell infiltrate embedded in a variable degree of fibrous stroma: only 2 of the reported cases exhibited the morphologic features of inflammatory myofibroblastic tumor. These morphologic features may raise problems in the differential diagnosis with other plasma cell–rich disorders, including infectious diseases and auto(dys)immune conditions, including the recently described “IgG4-related sclerosing disease.” In view of these considerations, a contemporary diagnostic approach to thyroid plasma cell granuloma is therefore discussed here.

Bilateral inflammatory pseudotumour of the trigeminal nerve: a diagnostic challenge

Inflammatory pseudotumour (IPT) is an uncommon disease with undefined pathogenesis. It is often characterized by local aggressiveness with compressive and displacing effects on surrounding structures. It may appear in different regions of the body, rarely involving perineural structures unilaterally. We present a case of a bilateral IPT around trigeminal branches in a patient with a long-term history of periorbital swelling and proptosis.

Inflammatory myofibroblastic tumor of the cerebellar hemisphere--case report

A 60-year-old man presented with a rare cerebellar inflammatory myofibroblastic tumor (IMT) manifesting as gait disturbance and dysarthria. Brain magnetic resonance imaging demonstrated an intra-axial round-shaped isointense mass homogeneously enhanced with gadolinium in the right cerebellar hemisphere, as well as perifocal edema extending to the brain stem and right thalamus. The tumor was elastic hard and was resected en bloc with a clear margin. Histological examination revealed IMT with spindle cells and collagen, but negative for anaplastic lymphoma kinase expression. IMT most commonly affects the lung, but may involve many other parts of the body. There is some debate regarding the disease entity of IMT in the central nervous system (IMT-CNS) because of its rarity and high frequency of recurrence. IMT-CNS is an important differential diagnosis among tumor-like intracranial lesions and total resection is required.

Oral inflammatory myofibroblastic tumor: case report and review of literature

Inflammatory myofibroblastic tumor (IMT) is a rarely described tumor of unknown etiology and pathogenesis. It occurs primarily in the lungs, but has occurred in other extra-pulmonary sites. Histologically these lesions appear as an inflammatory infiltrate within a variably myofibrotic background. Current evidence shows that inflammatory myofibroblastic tumors are neoplastic processes resulting from chromosomal translocations that often cause an overexpression of ALK kinase, which is often assessed using immunohistochemical studies. Currently, the biological behavior of oral inflammatory myofibroblastic tumor is still uncertain. This article describes the clinical, histological, and operative features of a case of IMT of the oral cavity.

Pathological features of IgG4-related sclerosing disease

PURPOSE OF REVIEW

The spectrum of IgG4-related systemic disease (IgG4-RSD) continues to widen. At most of the sites involved by this condition, the clinical presentation can mimic neoplasm. Pathologic assessment of small biopsies can be critical to proper management. This review summarizes the histologic features of IgG4-RSD and the role of immunohistochemistry of IgG4 in the diagnosis.

RECENT FINDINGS

The review period saw further expansion of the list of sites putatively involved by IgG4-RSD, with new, or more detailed, entries related to lung, lymph nodes, stomach, and thyroid. A tentative consensus was reached on the issue of subtypes of autoimmune pancreatitis. The role of immunohistochemistry for IgG4 as an adjunct to the diagnosis of IgG4-RSD was further clarified.

SUMMARY

Sclerosing lymphoplasmacytic inflammation at almost any site can represent a manifestation of IgG4-RSD. There are several histologic features that can suggest the diagnosis. Immunohistochemistry for IgG4 is a useful diagnostic test to further support the diagnosis.

Inflammatory myofibroblastic tumor in the intradural extramedullary space of the lumbar spine with spondylolisthesis: case report and review of the literature

An inflammatory myofibroblastic tumor (IMT) is a rare disease entity reported to arise in various organs but still thought to be a neoplastic or reactive inflammatory condition controversially. The author reports an extremely rare case of intradural extramedullary IMT of lumbar spine which was presenting radiculopathy and neurogenic intermittent claudication due to concomitant spondylolisthesis.

Neurological, imaging and pathological features of a meningeal inflammatory pseudotumour in a Maltese terrier

A five-year eight-month-old Maltese terrier was presented with a 3-week history of progressive paraparesis and pelvic limb ataxia. Neurological examination was consistent with a lesion involving the T3-L3 spinal cord segments. Myelogram and magnetic resonance imaging revealed a spherical, intradural-extramedullary mass lesion at T13/L1. A dorsal laminectomy, durotomy and debulking of the mass were performed. Histopathologic examination revealed a highly cellular tissue, most likely of mesenchymal origin, infiltrated by many lymphocytes, macrophages and neutrophils. The pathological diagnosis of an inflammatory pseudotumour was made. Postsurgical analgesia was achieved with opioids and 2 mg/kg carprofen twice daily for 5 days. When the histopathological diagnosis was made, a tapering course of 1 mg/kg prednisolone twice daily was prescribed, with dose reduction by approximately 50% every 4 to 6 weeks over a 4-month period. Magnetic resonance imaging was repeated at 22, 32 and 85 weeks postsurgery; no signs of regrowth could be detected and the patient recovered with residual mild paraparesis. Inflammatory pseudotumour has not been documented previously at this site in dogs and, although rare, should be considered in the differential diagnosis of a focal mass lesion affecting the spinal cord. Surgical debulking and immunomodulatory therapy can be curative.