Invasive inflammatory myofibroblastic tumor of the lung

Primary Lung Tumors in Children: Insights from a Single-Center Case Series

Background: Primary lung tumors in pediatric patients are rare, predominantly malignant, and present diagnostic challenges due to symptom overlap with more common conditions such as inflammatory processes or asthma. Evidence-based approaches for managing these rare neoplasms in childhood are scarce. This retrospective study reports the experience of a pediatric referral center in diagnosing and treating these tumors. Methods: Pediatric primary lung tumors treated at Giannina Gaslini Children's Hospital between January 2016 and January 2024 were included. Data on clinical presentation, histopathology, imaging, treatment approaches, and outcomes were systematically collected and analyzed. Results: Nine patients (six males and three females) were identified, with a mean age (±SD) at diagnosis of 8.81 ± 5 years. The most common clinical manifestation was recurrent pneumonia (four patients), followed by persistent cough and wheezing (three patients). The average duration of symptoms before diagnosis was 12.8 months ± 12.2 months. Histopathological diagnoses were typical carcinoid tumors (n = 2), atypical carcinoid tumors (n = 2), inflammatory myofibroblastic tumors (n = 2), congenital peribronchial myofibroblastic tumor (n = 1), myoepithelial carcinoma (n = 1), and pleuropulmonary blastoma (n = 1). Radical surgery resulted in complete response for seven patients, with a median follow-up of 52 months (IQR 39 months). The myoepithelial carcinoma was treated with multimodal therapy, relapsed after 17 months, and adjuvant chemotherapy is currently ongoing. Neoadjuvant chemotherapy for the pleuropulmonary blastoma is currently ongoing. Conclusions: Primary lung tumors in children, though rare, may have favorable outcomes when appropriately managed. Nonspecific clinical presentations often contribute to diagnostic delays. This study highlights the critical need of thorough evaluation in cases of persistent, therapy-resistant aspecific respiratory symptoms. Early diagnosis, coupled with complete surgical resection, significantly improves prognosis.

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.

Steroid responsive inflammatory myofibroblastic tumor of the lung evaluated by FDG PET/CT imaging

A 68-year-old gentleman was referred for ¹⁸F-FDG PET/CT for a pulmonary mass in the left upper lobe which demonstrated intensely FDG-avid confluent pulmonary consolidation in the left upper lobe (SUV_max 15.1). Histopathologic biopsy of the left upper lobe lung mass was consistent with inflammatory myofibroblastic tumor (IMT). The patient was started on steroid treatment in conjunction with antibiotics. Follow-up FDG PET/CT 3 weeks after commence of treatment showed remarkable response of the IMTs to therapy with much less avid FDG uptake (SUV_max 5.4) and marked improvement in the pulmonary consolidation. Nevertheless, the patient underwent left upper lobe lobectomy due to evidence of persistent cystic disease and malignant potential associated with IMTs. Final histopathology was consistent with IMT with no evidence of malignancy.

Inflammatory myofibroblastic tumours of the thorax: Radiologic and clinicopathological correlation

CONTEXT AND AIMS

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

MATERIALS AND METHOD

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

RESULTS

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

CONCLUSIONS

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

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

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm that may arise in soft tissues of nearly every organ. Although IMTs are the most common lung tumors in pediatric populations, these tumors are extremely rare in adults, constituting less than 1% of adult lung tumors. IMTs are characterized by proliferating spindle cells with variable inflammatory component. The biological behavior of lung IMTs in adults is highly unpredictable, which confounds diagnosis and treatment. We retrospectively investigated patients with pulmonary lesions and the histopathologic diagnosis of inflammatory myofibroblastic tumor or its synonymous names (Plasma Cell Granuloma, xanthogranuloma, inflammatory pseudotumor, fibroxanthoma, and fibrous histiocytoma) at the MD Anderson Cancer Institute in the period between August 2000 and August 2016. We describe 7 adult cases of IMT of the lung that were diagnosed at MD Anderson Cancer Center. These cases highlight the tumor's variability in terms of clinical presentation, histopathology, and biologic behavior, and underscore the challenges in the management of these rare lung neoplasms.

Inflammatory myofibroblastic tumor of the lung in pregnancy mimicking carcinoid tumor

Inflammatory myofibroblastic tumors (IMT) are uncommon neoplasms of the lung in adults. They constitute less than 1% of all lung neoplasms and usually present as parenchymal masses. Diagnosis requires a high index of suspicion. They are characterized by spindle-shaped tumor cells (fibroblasts/myofibroblasts) in a background of lymphoplasmacytic infiltrate. About 50% of the tumors harbor an ALK gene rearrangement. They have to be differentiated from inflammatory pseudotumors (IPT), which show increased number of IgG4 plasma cells on immunostaining and are negative for anaplastic lymphoma kinase (ALK) protein. Herein, we present a case of a 28-year old female who presented with hemoptysis and was diagnosed with an IMT of lung in the first trimester of pregnancy. We have not only reviewed the occurrence of IMT during pregnancy but also discuss the management options for IMT during pregnancy.

Epithelioid inflammatory myofibroblastic sarcoma: a case report

Inflammatory myofibroblastic tumor (IMT) of the lung is a rare malignancy with few cases reported in the literature. Histologically, it is composed by spindle cells and an infiltrate of inflammatory cells. Children and young, non-smoking adults constitute the majority of cases, the clinical behavior ranges from a benign entity to a malignant process with rapid recurrence and metastatic progression. We present a case of epithelioid inflammatory myofibroblastic sarcoma (EIMS) of the pleura, a malignant variant of IMT, which was initially treated with debulking surgical resection followed by systemic chemotherapy. The tumor was found to have an anaplastic lymphoma kinase (ALK) gene rearrangement. An ALK directed tyrosine kinase inhibitor was used with an impressive response, the patient remains in remission nearly 1 year after presentation. The pathogenesis, pathologic findings, clinical behavior and imaging of pulmonary EIMS are discussed.

Inflammatory myofibroblastic tumor of the lung indistinguishable from adenocarcinoma on imaging studies

We present the case of a right lung nodule discovered on routine chest x-ray in an asymptomatic 62-year-old man. CT revealed a spiculated nodule in segment 1 of the right upper lobe, 2.2 cm in diameter and without calcification. The nodule showed high focal FDG uptake (SUVmax, 17.8) on PET. Right upper lobectomy was performed under the diagnosis of adenocarcinoma; however, the histopathologic findings were of inflammatory myofibroblastic tumor.

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.

Intratracheal inflammatory myofibroblastic tumour mimicking severe acute asthma

A 3-year-old boy presented with severe airway obstruction which was diagnosed as asthma. He improved but had repeated episodes of severe airway obstruction. On clinical examination, he had a tracheal cough and monophonic wheezing. Imaging revealed a large lesion in the distal part of the trachea which was confirmed by bronchoscopy. The lesion was surgically removed. Histology revealed features characteristic of an inflammatory myofibroblastic tumour. Following the resection there is no recurrence of the lesion.

Multifocal intrathoracic inflammatory myofibroblastic tumour in children

Pulmonary inflammatory myofibroblastic tumour is the most common benign pulmonary tumour in childhood; however it is seldom diagnosed radiologically. We report three cases of biopsy-proven inflammatory myofibroblastic tumour that presented as large aggressive intrathoracic masses mimicking a malignant process. Two cases also had multifocal areas of origin. The possibility of inflammatory myofibroblastic tumour should be considered in a child presenting with a large aggressive pleuropulmonary mass lesion even with multifocal origin.

Inflammatory myofibroblastic tumor of the lung--a case report

A 45-year-old man presented with a six-month history of progressive dyspnea with productive cough and wheezing. The patient was a heavy smoker and had a history of tongue cancer, hypertension, and asthma. Chest X-ray and computed tomography showed a mass lesion in the left hilar region and total collapse of the upper left lobe of the lung. Bronchoscopy revealed a whitish solid tumor obstructing the left upper lobe bronchus. Positron emission tomography showed increased tracer uptake in the lesion. A thoracoscopic lobectomy of the left upper lobe of the lung was performed. The final pathologic diagnosis was inflammatory myofibroblastic tumor.