Clinical and Histopathologic Correlates and Management Strategies for Inflammatory Myofibroblastic tumor of the lung. A case series and review of the literature

A comprehensive review of benign tumors in the lung

PURPOSE OF REVIEW

The purpose of this review is to provide clinicians a comprehensive overview of the epidemiology, clinical symptoms, radiological features, pathological features, and management recommendations for the vast majority of benign lung tumors. Benign lung tumors are very rare with incidence ranging from 1 in 1000 to 1 in 1 million. Despite not being malignant, certain benign tumors carry significant morbidity and mortality along with diagnostic challenges.

RECENT FINDINGS

Advancements in genomic sequencing have led to discovery of mutations in particular benign lung tumors. Improved genotyping have aided the diagnosis of certain tumors and the identification of lung lesions with malignant transformation potential. Genomic understanding has also led to targeted therapy for tumors with significant morbidity.

SUMMARY

Despite radiographic and pathologic advances in understanding benign lung tumors, the paucity of cases continues to impact management recommendations and early detection. Global collaborative initiatives in compiling and analyzing cases are essential for stronger evidence based management recommendations.

Can Chemotherapy Facilitate Less Morbid Surgery in Multicentric Intra-abdominal Inflammatory Myofibroblastic Tumor?

BACKGROUND

Inflammatory myofibroblastic tumor is a rare benign neoplasm affecting young adults and children. Although often considered benign, its locally aggressive nature and tendency to recur make its management immensely challenging, particularly without robust evidence to guide treatment. Surgical excision offers the best hope for a cure; however, this can lead to significant morbidity and may not always be possible, especially for multicentric diseases.

CASE PRESENTATION

We report a multicentric abdominal inflammatory myofibroblastic tumor in a 6-year-old girl who presented with massive abdominal distention. The sheer size of the mass, coupled with multicentric presentation and absent mobility on clinical examination, would have led to a very morbid surgical exploration. This patient was treated with initial chemotherapy, which led to a dramatic response in both symptoms and size of masses, facilitating a complete surgical resection with negligible postoperative morbidity.

CONCLUSIONS

Although surgery is the preferred treatment for a resectable disease, initial chemotherapy for multicentric or locally advanced inflammatory myofibroblastic tumors facilitates complete surgical resection.

Therapeutic strategy and prognostic analysis of inflammatory myofibroblastic tumor in the head and neck: a retrospective study

Objective

This study aimed to investigate the clinical features, treatment methods, and prognosis of head and neck inflammatory myofibroblastic tumor (HNIMT).

Methods

A retrospective analysis was conducted using the clinical data of 12 HNIMT patients who were admitted to Shanxi Cancer Hospital between January 2016 and December 2023. This analysis focused on their clinical manifestations, pathological characteristics, treatment strategies, and prognosis.

Results

Among the 12 cases analyzed, four involved inflammatory myofibroblastic tumors (IMT) located in the nasal sinuses or nasopharynx, with symptoms including nasal congestion, rhinorrhea, and maxillofacial swelling. Two cases each in the salivary glands and oral cavity presented as localized, painless masses. One right cervical IMT case also presented as a painless lump. Two laryngeal IMT cases had hoarseness, and one subglottic endotracheal IMT case showed inspiratory dyspnea. All patients received surgery, with postoperative pathology confirming IMT. During follow-up, four cases recurred. Finally, nine patients were disease-free, two survived with disease, and one died.

Conclusions

HNIMT is a rare, low-grade malignant or borderline tumor that is generally associated with a favorable prognosis. Accurate diagnosis relies on pathological examination, and surgical resection remains the primary treatment for HNIMT. The need for adjuvant therapy following surgery should be determined by clinicians based on tumor location, surgical approach, and the presence of high-risk factors.

Clinical diagnosis and treatment of abdominal inflammatory myofibroblastic tumors

OBJECTIVE

This study aims to summarize the clinicopathological characteristics, treatment methods, and prognosis of these patients. The goal is to enhance our understanding of the disease and provide insights for the standardized diagnosis and treatment of abdominal inflammatory myofibroblastic tumors(IMT).

METHODS

This retrospective cohort study included clinical data of 26 patients with abdominal IMT admitted to the First Hospital of Jilin University between January 2015 and December 2023. The clinical manifestations, pathological features, treatment methods, and prognoses were analyzed.

RESULTS

Among 26 patients, 6 had hepatic IMT, 2 splenic IMT, and 1 abdominal wall IMT, all detected incidentally as painless masses during routine exams. Six patients with mesenteric IMT reported abdominal distension, pain, nausea, vomiting, and low-grade fever. Of five patients with gastric IMT, three had gastrointestinal bleeding, one had distension and fever, and one had dysphagia. Four small intestine cases included one asymptomatic and three with obstruction symptoms. The colon and rectal cases presented with intermittent hematochezia. Surgery was performed in 24 patients, and 2 with metastases received palliative therapy. During follow-up, five patients relapsed; three received palliative therapy, and two had surgery. At last follow-up, 20 patients were disease-free, 3 were living with tumors, and 3 had died.

CONCLUSIONS

Abdominal IMTs are rare, low-grade tumors with favorable prognoses. Pathological examination is essential for diagnosis, and surgery is the primary treatment. Adjuvant therapy depends on tumor location and risk factors. Close follow-up is necessary due to the potential for recurrence and metastasis.

Inflammatory myofibroblastic tumors: Diagnostic challenges and treatment strategies - A case report and literature review

Inflammatory myofibroblastic tumors (IMTs) are rare benign mesenchymal tumors that present diagnostic challenges due to their diverse clinical and radiological manifestations. We present a case of a 19-year-old female with a history of intermittent hemoptysis. Imaging studies suggested a mediobasal lung lesion, prompting further evaluation. Bronchoscopy revealed vascular changes, and PET imaging indicated high metabolic activity. A left lower lobectomy was performed for diagnostic and therapeutic purposes, confirming the diagnosis of IMT characterized by spindle cell proliferation and inflammatory infiltrates. Surgical resection remains the cornerstone treatment, offering favorable outcomes with rare recurrence. Follow-up underscores the importance of monitoring and assessing prognostic factors to optimize patient management.

A Case Report of Inflammatory Myofibroblastic Tumor: A Rare Benign Lung Tumor

Inflammatory myofibroblastic tumors (IMTs) of the lung are a rare type of mesenchymal tumors that tend to occur more in the lungs of children. They are extremely rare in adults. IMTs require extensive pulmonary resection because they are commonly locally invasive. The key to preventing recurrence is complete resection, and the prognosis is excellent after surgery. We report a case of a patient with an inflammatory pseudotumor of the lung. The patient is a 27-year-old female who presented with a dry cough. A chest radiograph and computed tomography showed a lesion in the left main bronchus and near-total left lung collapse. As surgery was necessary to establish the diagnosis, left pneumonectomy was performed followed by a histological examination of the surgical specimen which confirmed inflammatory pseudotumor.

A case of inflammatory myofibroblastic tumor harboring EML4-ALK fusion with a brain metastasis responding to alectinib

Metastatic inflammatory myofibroblastic tumor (IMT) is very rare and detailed reports on diagnosis and treatment are limited. Here, we report a case of metastatic IMT with ALK rearrangement. A 73-year-old woman was diagnosed with IMT involving a brain metastasis. Next generation sequencing (NGS) panel testing with Oncomine dx target test revealed that her tumor was positive for EML4-ALK. Treatment with alectinib was initiated, resulting in remarkable shrinkage of both the primary tumor and the brain metastasis. This report is the first to identify ALK rearrangement in IMT using a commercially available NGS panel testing, followed by treatment with alectinib. This case suggests that NGS panel testing may be useful in the diagnosis and treatment of patients with metastatic IMT.

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.

Traumatic tumor hemorrhage of inflammatory myofibroblastic tumor of the lung

A 23-year-old female with a history of idiopathic epilepsy was found to have a right chest cavity shadow in a school health checkup 5 years before. CT revealed a thin-walled cavity lesion in the right middle lobe containing a ball-like mass, showing air crescent sign. After falling due to a seizure, she was transported by ambulance and admitted. CT revealed diffuse ground-glass opacities throughout the right lung field. Bronchoscopy revealed bloody bronchial alveolar lavage fluid. Due to the tumor hemorrhage, an elective simple right middle lobe resection was performed without complications. The initial immunohistochemical staining was negative for ALK using ALK1 clone; however, subsequent staining of ALK by D5F3 and 5A4 clone was positive. Immunostaining findings led to a diagnosis of inflammatory myofibroblastic tumor. The patient remains under regular observation and has experienced no recurrence over the 6-year postoperative period. This case contains two different points: the first is that a cavity lesion of inflammatory myofibroblastic tumor may cause traumatic bleeding and should be treated with caution; the second is that attention should be paid to differences in stainability among clones when diagnosing inflammatory myofibroblastic tumor.

Crizotinib combined with bronchoscopic interventional treatment in ALK-positive inflammatory myofibroblastic tumor of left main stem bronchus: a case report

BACKGROUND

Inflammatory myofibroblastic tumor (IMT), also known as an inflammatory pseudotumor, is a unique type of intermediate soft tissue tumor that commonly occurred in the lung. Its unclear etiology and cellular activity brought about the confusion not only in naming of it, but also in diagnosis and treatment.

CASE PRESENTATION

We reported the case of an 18-year-old male student who suffered from shortness of breath, chest tightness and chest pain. Chest computed tomography scan showed a spherical neoplasm blocking left main stem bronchus. After fiberoptic bronchoscopy procedure, the results of histopathological and immunohistochemical analysis indicated an IMT. The targeted next generation sequencing based genomic profiling of the tumor using formalin-fixed and paraffin embedded tissue was performed and a EML4-ALK fusion was detected. The patient began to receive Crizotinib, a ALK tyrosine kinase inhibitor, at a dose of 250 mg twice daily orally. The patient has recovered well after the operation, and no recurrence or metastasis has been found after 12 months' follow-up.

CONCLUSION

By means of the diagnosis and treatment of this case, the characteristics and therapies of IMT are illustrated. In addition, it also provides a reference for the therapeutic strategy of IMT in the future.

Case report: Uniportal video-assisted thoracoscopic sleeve lobectomy in a 6-year-old patient with inflammatory myofibroblastic tumor (IMT)

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm that can occur in various organs, including the lung. Surgical resection is usually the preferred treatment for localized IMT.A 6-year-old female was admitted to our hospital with complaints of "coughing and vomiting for 6 days". A chest CT scan revealed occlusion of the left main bronchus, segmental atelectasis of the left lower lung, and cystic low-density shadows along the bronchial pathway. Subsequent fiberoptic bronchoscopy confirmed the diagnosis of IMT through pathological biopsy. After excluding surgical contraindications, the patient underwent uniportal video-assisted thoracoscopic sleeve lobectomy for treatment. The patient had an uneventful postoperative course and was discharged four days after surgery. After one month, the patient received a follow-up examination and reported no significant discomfort. A chest CT scan revealed no postoperative complications.Our experience suggests that uniportal video-assisted thoracoscopic surgery may be a safe and effective approach for the treatment of pediatric patients with IMT requiring complex surgical procedures such as sleeve lobectomy and tracheoplasty.

Inflammatory Myofibroblastic Tumor of the Larynx: Report of a Case

PURPOSE

Inflammatory myofibroblastic tumor (IMT) is a rare tumor composed of mesenchymal myofibroblastic spindle cells enveloped by an inflammatory infiltrate. Historically, this tumor sparked debate regarding whether it was a true malignancy with metastatic potential or merely a locally destructive physiologic inflammatory response. Few reports of IMT exist in the recent literature, with the majority of cases occurring in the pediatric population and favoring the lungs. Here we present an exceedingly rare case of IMT involving the larynx of a 22-year-old female.

RESULTS

A hemorrhagic and solid mass of the right true membranous vocal fold was excised and sent for histopathological assessment. Features of the surgical specimens were diagnostic for IMT. Intralesional steroid therapy was selected for additional treatment. Panendoscopy facilitated surveillance for any additional or recurrent lesions, of which there were none. At 11 months post-excision, follow-up MRI revealed symmetric vocal cords without evidence of any masses.

CONCLUSIONS

Although rare, laryngeal IMT should be considered in any patient presenting with hoarseness due to a vocal fold mass. Based on the successful treatment of our patient, we suggest that our approach of surgical excision followed by intralesional corticosteroid injection may be an efficacious treatment approach for this rare tumor. However, more research is warranted to elucidate the most effective, safe, and cost-effective treatment approach.

Surgical treatment for lung metastasis of inflammatory myofibroblastic tumor of the lung: A case report

Inflammatory myofibroblastic tumor (IMT) is a rare disease that is considered an intermediate neoplasm, with the risk of recurrence and metastasis. Surgical treatment is the standard therapy for IMT, although there are only a few reports of surgery for lung metastasis of pulmonary IMT. We opine that surgical treatment might be effective not only for localized tumors, but also for cases of lung metastasis of IMT.

Multisystem ALK-positive histiocytosis: a multi-case study and literature review

BACKGROUND

Anaplastic lymphoma kinase (ALK)-positive histiocytosis, a novel rare histiocytic proliferation, was first described in 2008; it occurs in early infancy with liver and hematopoietic involvement. The spectrum was subsequently broadened to include localized diseases in older children and young adults. However, its full clinicopathological features and molecular lineage have not been fully elucidated.

RESULTS

Here, we report four cases of multisystem ALK-positive histiocytosis without hematopoietic involvement. Clinically, three patients were adults aged between 32 and 51 years. Two patients', whose main manifestations were intracranial mass and numerous micronodules in the thoracoabdominal cavity organs and skin papules respectively, had a partial response to ALK inhibitors after surgery. One patient presented with mediastinal neoplasm without surgical treatment, and progressive disease occurred after two years of ALK inhibitor therapy. The fourth patient was a 17-month-old male with a large intracranial mass and presented with a poor response to ALK inhibitor and chemoradiotherapy; he died eight months after surgery. Pathologically, the histiocytes were large, with abundant eosinophilic cytoplasm, and mixed with variable numbers of foamy cells and Touton giant cells. Interstitial fibrosis was also observed. Histiocytes were positive for macrophage markers (CD68 and CD163) and ALK. KIF5B-ALK fusions were detected in two cases, EML4-ALK in one, and both DCTN1-ALK and VRK2-ALK fusions were detected in one case.

CONCLUSIONS

We observed that ALK inhibitors present robust and durable responses in adult patients but a poor response in young children with central nervous system involvement. There is no consensus on the optimal treatment regimen and long-term prognosis requires further observation. Moreover, every unusual histiocytic proliferative lesion, especially unresectable and multisystem involvement, should be routinely tested for ALK immunohistochemical staining to identify this rare disease.

Inflammatory Myofibroblastic Tumor Mimicking a Cavitary Lesion in the Lung: A Case Report and a Comprehensive Literature Review

Inflammatory myofibroblastic tumors (IMTs) are a group of soft tissue neoplasms with a predilection for the lungs and abdominopelvic cavity, characterized by a mixture of fasciitis-like, compact spindle cells, hypocellular fibrous histologic patterns, and distinctive molecular features. Due to their unspecified symptoms and non-specific radiologic presentation, the histopathologic and immunohistochemical analysis of a biopsy specimen is crucial for the diagnosis. We present a case of a 30-year-old man with intermittent hemoptysis diagnosed with a pulmonary IMT. We aim to review the literature regarding its definition, clinical findings, diagnosis, treatment, and prognosis. The treatment for an IMT is based on its location and extent, including complete surgical resection, which has a good prognosis compared to corticosteroids, chemotherapy, radiotherapy, and non-steroidal immunomodulation in patients who are not good surgical candidates. Further investigative studies with larger sample sizes and longer meticulous follow-ups are needed to demonstrate this neoplastic disease's natural history and find appropriate management for it.

Endotracheal inflammatory myofibroblastic tumour: A rare cause of central airway occlusion in adults

Inflammatory myofibroblastic tumour (IMT) is an unusual myofibroblastic spindle cell neoplasm that is rarely discovered in the airway of adults. Previously, it was regarded as a reactive lesion and was infamously known as inflammatory pseudotumour before recent insights revealed that significant majority of cases harboured neoplastic genes. Diagnosis is difficult as clinical presentation and imaging findings are non-specific. Diagnosis and a favourable prognosis require the complete resection of the tumour. Detection of the anaplastic lymphoma kinase expression via immunohistochemistry expedites diagnosis. We report a young adult with an endotracheal mass occluding the central airway. The patient successfully underwent bronchoscopic resection using interventional techniques. IMT was diagnosed. No recurrence was seen after a year of surveillance. Due to the rarity of the disease, the recurrence rates for large airway disease is unknown. Recurrence rates for pulmonary lesions is reported to be lower compared to extrapulmonary IMTs and recurrence is unlikely if compete surgical excision is achieved.

Common Presentation of Uncommon Disease: Inflammatory myofibroblastic tumor of the lung, case report

Background

Inflammatory myofibroblastic tumor (IMT) of the lung is a rare lung tumor, accounting for 0.7% of all lung tumors. They are usually benign, but can invade surrounding structures, undergo malignant transformation, recur, or even metastasize.

Case report

We report a 44-year-old adult diabetic male from Saudi Arabia who had been suffering from cough with severe sputum and left shoulder pain for 2 weeks. Chest radiography (X-ray and computed tomography (CT)) revealed the presence of a mass lesion in the left lower upper lobe with central cavitation. The diagnosis of inflammatory myofibroblast lung tumor was confirmed by histological and immunohistochemical examination of the CT guided lung biopsy. The patient was successfully treated with surgical resection of the tumor by left limited thoracotomy with safety margin, and IMT was also documented.

Conclusion

A high degree of suspicion of a solitary pulmonary mass is required for diagnosis and management of an inflammatory myofibroblastic lung tumor. The clinical and radiologic presentation of an inflammatory myofibroblastic tumor is nonspecific and the diagnosis is rarely made before surgical biopsy. Histologic and immunohistochemical examination is usually required to confirm the diagnosis and prevent recurrence.

Case Report: Early Distant Metastatic Inflammatory Myofibroblastic Tumor Harboring EML4-ALK Fusion Gene: Study of Two Typical Cases and Review of Literature

Inflammatory myofibroblastic tumor (IMT) is a distinctive neoplasm that frequently arises in the lung and accounts for ~1% of lung tumors. Distant metastatic IMT is extremely rare and has been poorly investigated. This analysis was specifically performed to explore the clinicopathological and genetic features of early distant metastatic IMT. Two typical patients with distant metastatic IMTs were selected, which accounted for 1.13% of all diagnosed IMTs in the last 5 years. One patient was a 55 year-old male, and the other patient was a 56 year-old female. Both primary tumors arose from the lung, and the initial clinical symptoms of the two patients involved coughing. Both of the imaging examinations showed low-density nodular shadows in the lungs with enhancement around the mass. Microscopically, dense arranged tumor cells, prominent cellular atypia, and high mitotic activity with atypical form were more prominent in the metastatic lesions than in the primary lesions. All of the primary and metastatic tumors in both cases showed positive anaplastic lymphoma kinase (ALK) immunostaining and ALK rearrangement via fluorescence in situ hybridization. The EML4 (exon 6)-ALK (exon 20) fusion variant (v3a/b) was identified by using next-generation sequencing (NGS) and was verified by using reverse transcription polymerase chain reaction (RT-PCR). Furthermore, intronic variants of NOTCH1 and synonymous variants of ARAF were also detected via NGS in one IMT for the first time and were verified in all of the primary and metastatic lesions via PCR. Distant metastasis occurred during a short period of time (1 and 2 months) after the first surgery. One patient presented with multiple metastases to the subcutaneous tissue and bone that responded to ALK inhibitor alectinib therapy, and the tumor was observed to regress 10 months after the initial ALK inhibitor therapy. In contrast, the other patient presented with subcutaneous neck metastasis without ALK inhibitor treatment and succumbed to the disease within 3 months after the surgery. This study demonstrated the possible role of EML4-ALKv3a/b in the malignant progression of IMT and proposed certain therapeutic effects of ALK inhibitors on multiple metastatic IMTs.

Operated pulmonary inflammatory myofibroblastic tumors: Our experience with 17 cases

Background

In this study, we aimed to evaluate the clinicopathological features of pulmonary inflammatory myofibroblastic tumor cases operated in our clinic.

Methods

A total of 17 inflammatory myofibroblastic tumor patients (5 males, 12 females; median age: 46 years) who were operated in our clinic between February 2000 and July 2019 were included. Data including sex, age, symptoms, accompanying diseases, tumor localization, tumor diameter, endobronchial extension, maximum standard uptake value of the tumors, surgery type, recurrence, and survival data were analyzed.

Results

Two patients were diagnosed preoperatively and two patients were diagnosed during surgery using frozen-section method before resection. Three (17.7%) patients underwent pneumonectomy, five (29.4%) patients lobectomy, three (17.7%) patients segmentectomy, five (29.4%) patients wedge resection, and one (5.8%) patient bronchial sleeve resection. All patients had complete resection with negative margins. None of them had lymph node metastasis. Median follow-up was 122 (range, 8 to 245 months) months. None of the patients received adjuvant therapy, there was no tumor recurrence or tumor-related death.

Conclusion

It is difficult to make a preoperative diagnosis of inflammatory myofibroblastic tumor patients. Systematic lymph node dissection is not required in diagnosed patients. Complete resection is the most important prognostic factor, and it is critical to achieve this with the smallest resection possible.

Novel treatment of endobronchial inflammatory myofibroblastic tumor in a child

Isolated endobronchial inflammatory myofibroblastic tumors (IMT) are rare, accounting for about 1% of primary endobronchial tumors in children. The mainstay of treatment for this tumor has been surgical resection. Recently, the identification of anaplastic lymphoma kinase (ALK) gene mutations in half of IMTs and promising results of treatment with ALK inhibitors in other ALK-positive tumors have opened the possibility of alternative approaches. We present a 4-year-old child with an ALK-positive endobronchial IMT, treated with endoscopic resection and neoadjuvant therapy with crizotinib, without evidence of tumor recurrence 2 years after the initial resection.

Thoracic Multidetector Computed Tomography Evaluation of Inflammatory Myofibroblastic Tumor of the Lung in Pediatric Patients in the Era of Modern Diagnosis

PURPOSE

The purpose of this study was to investigate the characteristic thoracic multidetector computed tomography (MDCT) findings of pathologically proven inflammatory myofibroblastic tumor (IMT) of the lung in children in the era of modern understanding based on refined pathologic diagnosis.

MATERIALS AND METHODS

All pediatric patients (age 18 y and above) with a known pathologic diagnosis of IMT of the lung who underwent thoracic MDCT studies from May 2008 to December 2020 were included. Two pediatric radiologists independently evaluated thoracic MDCT studies for the presence of abnormalities in the lung (nodule, mass, cyst, ground-glass opacity, consolidation), pleura (pleural effusion, pneumothorax), and mediastinum and hilum (lymphadenopathy). When a lung abnormality was present, the number, size, composition (solid, cystic, or combination of both), location (laterality, lobar distribution, and intraparenchymal vs. pleural-based), borders (well-circumscribed vs. ill-defined), the presence and type of associated calcification (punctate, dense, curvilinear, or flocculent), the presence of associated cavitation, contrast enhancement pattern (homogeneous, heterogenous, central, or peripheral), and other associated findings (neural foramen involvement, anomalous vessels, mass effect, and invasion of adjacent thoracic structures) were also evaluated. Interobserver agreement between 2 independent reviewers was evaluated with κ statistics.

RESULTS

In all, 12 thoracic MDCT studies from 12 individual pediatric patients (5 males [42%] and 7 females [58%]; mean age: 9.9 y; SD: 4.4 y; range: 2 to 16 y) comprised the final study population. All 12 thoracic MDCT studies (100%) were performed with intravenous contrast. The most frequent MDCT finding of IMT of the lung in children is a solitary (92%), pleural-based (83%), well-circumscribed (100%), solid (92%) mass with heterogenous contrast enhancement (100%), often with dense calcification (50%), which occurred in both lungs and all lobes with similar frequency. No pleural abnormality (pleural effusion, pneumothorax) or mediastinal abnormality (lymphadenopathy) was detected. In addition, although mass effect on adjacent thoracic structures was frequently seen (42%), no invasion, neural foramen involvement, or associated anomalous vessels was identified. There was excellent interobserver κ agreement between 2 independent reviewers for detecting abnormalities on thoracic MDCT studies (κ>0.95).

CONCLUSIONS

IMT of the lung in children typically presents as a solitary, pleural-based, well-circumscribed, solid mass with heterogenous contrast enhancement, often with dense calcification, without significant laterality or lobar preference. In addition, pleural or mediastinal abnormalities are characteristically absent. These notable MDCT attributes of IMT of the lung are an important and novel finding, with great potential to help differentiate pediatric IMT of the lung from other thoracic masses in children.

Clinicopathological features of gastric inflammatory myofibroblastic tumor: Report of five cases

The present study reported on the histomorphological observations and immunohistochemical features of five cases of gastric inflammatory myofibroblastic tumor (IMT). Loosely arranged fat fusiform myofibroblast-fibroblasts and diffusely or patchily distributed inflammatory cells, which formed a diverse morphological structure, were observed. In the mucous vascular structure, mucoid or collagenous areas, fibromatosis- or scar-like lesions were generally <10 mm in size and both had diffuse or patchy plasma cells, lymphocytes and other inflammatory-cell infiltration backgrounds. The immunophenotype was vimentin- and smooth muscle actin-positive with pan-cytokeratin, desmin and calponin expression and CD34-positive foci; furthermore, three cases were positive for anaplastic lymphoma kinase expression. Gastric IMT is rare, with unique histopathological changes and corrosion-like invasion of the smooth muscle of the stomach wall, blood vessels, nerves and adipose tissue. It should be differentiated from a variety of spindle cell tumor types and tumor-like lesions.

Ileal inflammatory pseudotumor in adolescent male patient with prior Burkitt lymphoma: A challenging diagnosis

Inflammatory pseudotumor is a rare benign mesenchymal pediatric neoplasm, that can mimic tumoral residue or relapse at metabolic imaging with nonspecific clinical presentation and difficult diagnosis. We present the case of a 14year old male patient with fever of unknown origin and large ileal mass, diagnosed with and treated for Burkitt lymphoma, who performed several 18-fluoro-deoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) scans, during and after first line chemotherapy, showing persistent and focal uptake, while ileal mass volume decreased dramatically and the patient was clinically asymptomatic. Histopathological analysis of residual ileal mass was suggestive for xanthomatous pseudotumor, a type of inflammatory pseudotumor. No more treatment was performed and a short-term follow up with 18F-FDG PET/CT showed tracer uptake intensity decreasing progressively over the next few months. This case reports an uncommon presentation of a rare disease, inflammatory pseudotumor of the small bowel developed at the site of treated Burkitt lymphoma, underscoring the potential role of 18F-FDG PET/CT imaging in the diagnosis and management of these rare neoplasms, particularly in asymptomatic patients.

Inflammatory Myofibroblastic Tumors in Children: A Clinical Retrospective Study on 19 Cases

Background: Inflammatory myofibroblastic tumor (IMFT) is a rare neoplasm mainly affecting children and young adults. We conducted a retrospective study to evaluate the clinical features and treatment alternatives of childhood inflammatory myofibroblastic tumors. Methods: A total of 19 patients who were pathologically diagnosed with IMT between December 2008 and October 2018 were included. Collected data were demographic information, main complaints, tumor characteristics, treatment, pathological results, immunohistochemical analysis, and prognosis. Results: The male/female ratio was 13:6. The mean age at disease onset was 44.9 ± 33.9 months (range 4 to 111 months). The mean tumor size was 6.5 ± 4.0 cm (range 1.2 to 17.0 cm). The most common site was the abdomen (13/19). The most commonly used detection tool was CT. Eleven patients (57.9%) had aggressive tumor growth, including eight receiving extensive resection and three receiving palliative resection due to high local invasiveness and postoperative chemotherapy. Eight cases whose tumors were completely enveloped received complete resection. Immunohistochemistry was performed for 17 patients and ALK positivity was found in 11 patients. Despite three children lost to follow-up, sixteen patients were followed up for 6 to 132 months (average 63.9 months, median 66 months). Of which, twelve children survived with no evidence of IMT, and four cases (21%) showed local recurrences (two of them died). No distant metastasis was detected. Conclusions: IMT is rare in children with various locations, mostly appearing in the abdomen. Whether the tumor could be completely removed, the location and the invasiveness of surrounding tissues might be highly prognosis-related.

Inflammatory myofibroblastic tumor of the lung: A rare entity

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor usually seen within the first and second decade. They are extremely rare in adults, constituting less than 1% of adult lung tumors. It's usually benign, but it had a tendency for local recurrence. We report a case of asymptomatic inflammatory myofibroblastic tumor of lung in a 46-year-old non-smoker woman.

Bronchoscopic Treatment of Endobronchial Inflammatory Myofibroblastic Tumors

Endobronchial localizations of inflammatory myofibroblastic tumors are very unusual. We report the multimodal, bronchoscopic management of 3 cases, offering durable local control in all cases (including 2 patients who were definitively cured). Although surgery is usually considered the gold standard, therapeutic bronchoscopy should probably be considered as a frontline option for proximal lesions with limited base (< 10 mm²) because of uncommon metastatic spread and delayed local recurrence. Of note, 1 of our cases is a rare airway case after allograft hematopoietic stem cell transplant.

Using CT texture analysis to differentiate between peripheral lung cancer and pulmonary inflammatory pseudotumor

Background

This study is to distinguish peripheral lung cancer and pulmonary inflammatory pseudotumor using CT-radiomics features extracted from PET/CT images.

Methods

In this study, the standard 18F-fluorodeoxyglucose positron emission tomography/ computed tomography (18 F-FDG PET/CT) images of 21 patients with pulmonary inflammatory pseudotumor (PIPT) and 21 patients with peripheral lung cancer were retrospectively collected. The dataset was used to extract CT-radiomics features from regions of interest (ROI), The intra-class correlation coefficient (ICC) was used to screen the robust feature from all the radiomic features. Using, then, statistical methods to screen CT-radiomics features, which could distinguish peripheral lung cancer and PIPT. And the ability of radiomics features distinguished peripheral lung cancer and PIPT was estimated by receiver operating characteristic (ROC) curve and compared by the Delong test.

Results

A total of 435 radiomics features were extracted, of which 361 features showed relatively good repeatability (ICC ≥ 0.6). 20 features showed the ability to distinguish peripheral lung cancer from PIPT. these features were seen in 14 of 330 Gray-Level Co-occurrence Matrix features, 1 of 49 Intensity Histogram features, 5 of 18 Shape features. The area under the curves (AUC) of these features were 0.731 ± 0.075, 0.717, 0.748 ± 0.038, respectively. The P values of statistical differences among ROC were 0.0499 (F9, F20), 0.0472 (F10, F11) and 0.0145 (F11, Mean4). The discrimination ability of forming new features (Parent Features) after averaging the features extracted at different angles and distances was moderate compared to the previous features (Child features).

Conclusion

Radiomics features extracted from non-contrast CT based on PET/CT images can help distinguish peripheral lung cancer and PIPT.

Successful treatment of pulmonary inflammatory myofibroblastic tumor with platinum-pemetrexed: The first report of two cases

Pulmonary inflammatory myofibroblastic tumor (IMT) is a rare tumor. Here, we report two cases of pulmonary IMT successfully treated with platinum and pemetrexed. The results from this study suggest that platinum‐pemetrexed might be an effective therapy in patients with IMT, but requires further investigation.

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

Background

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

Case presentation

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

Conclusions

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

Inflammatory Myofibroblastic Tumor of the Lung: An Extremely Rare Condition in Adults

Inflammatory myofibroblastic tumors (IMTs) of the lung were first reported in 1939. The most common site of predilection is the lungs of the pediatric population. They are extremely rare in adults, constituting less than 1% of adult lung tumors. They are mesenchymal neoplasms that may arise in the soft tissues of almost every organ. IMTs often arise from excessive inflammatory response, and as the name implies, they are composed of myofibroblastic spindle cells accompanied by an inflammatory infiltrate of plasma cells, lymphocytes, and eosinophils.