Computed tomographic and magnetic resonance features of inflammatory myofibroblastic tumor of the lung in children

Diagnosis of inflammatory myofibroblastic tumor in a pediatric patient initially suspected of tuberculosis

BACKGROUND

Symptoms of inflammatory myofibroblastic tumor (IMT) are atypical, and histopathological misdiagnosis of IMT is still inevitable. Here we present a pediatric case that an eight-year-old boy with recurrent fever for fifteen months, received anti-tuberculosis therapy for five months and was ultimately confirmed to be IMT.

CASE PRESENTATION

An eight-year-old boy experienced a recurrent fever for fifteen months, accompanied by cough, vomiting, meteorism, night sweating, and emaciation. Thoracoabdominal computer tomography revealed multiple enlarged lymph nodes in the thorax, abdomen, and axilla, as well as minimal bilateral pleural effusion. Histopathological examinations of the intestines and greater omentum implied fibrous tissue hyperplasia along with eosinophil and lymphocyte infiltration. The patient was initially misdiagnosed with tuberculosis, and symptoms were relieved partially following anti-tuberculosis treatment. However, after four months, the symptoms aggravated again and a subsequent histopathological analysis of a second sample from the greater omentum revealed the presence of IMT. Eventually, after surgical resection of the lesions and chemotherapy, the clinical symptoms in the child gradually alleviated.

CONCLUSIONS

The clinical course of IMT is variable, and pediatricians should pay attention to differentiating IMT from tuberculosis.

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.

Inflammatory myofibroblastic tumor of the prostate after transurethral resection of the prostate with negative expression of anaplastic lymphoma kinase: a case report

CONTEXT

Inflammatory myofibroblastic tumors are a rare type of soft-tissue tumor. Inflammatory myofibroblastic tumors are characterized by rearrangements involving the anaplastic lymphoma kinase gene locus on 2p23.

CASE REPORT

We report the case of a 67-year-old Chinese male who presented with dysuria and fever. Magnetic resonance imaging showed an irregular prostatic mass with an isointense signal and obscure boundary. Histopathological evaluation showed that the mass consisted mainly of spindle-shaped cells. Immunohistochemical evaluation showed that the tumor cells were negative for anaplastic lymphoma kinase.

CONCLUSIONS

Inflammatory myofibroblastic prostate tumors are rare lesions with unclear etiology. The pathological diagnosis is very important.

Pulmonary Inflammatory Myofibroblastic Tumor in Children: A Case Report and Brief Review of Literature

The inflammatory myofibroblastic tumor (IMT) is a rare lesion of unclear etiology and variable clinical course, consisting of a proliferation of fibroblasts and myofibroblasts, mixed with inflammatory cells. Synonyms of IMT are inflammatory pseudotumor and plasma cell granuloma reflecting the alleged inflammatory nature attributed to this lesion, even though this heterogeneity in the disease denomination is probably involved in a dispersion of the literature data. Among primary pulmonary neoplasms, it represents the most frequent endobronchial tumor of childhood and beyond the lung it has been described mainly in the bladder, mediastinum and mesentery. Despite having a tendency for local recurrence, the risk of distant metastasis is low. Clinical presentation depends on localization therefore lung peripheral lesions are often asymptomatic resulting in a delayed diagnosis. Radiological findings can suggest the diagnosis that must be confirmed by histopathology assessment. The tumor has been characterized by the application of immunohistochemical techniques, molecular biology and cytogenetics, which are very precious for the diagnosis. The therapeutic approach consists in the complete surgical excision of the lesion that normally ensures excellent survival. Due to the potential risk of recurrence, close clinical trial is indicated. To date only 24 cases of pulmonary IMT have been described, although the prevalence is probably higher. We present a case report of a 3-year-old girl with pulmonary IMT and a brief review of known literature cases in order to highlight the most common clinical presentations, the most useful diagnostic tools and therapeutic approach.

Specific imaging characteristic of solitary necrotic nodule of the liver: Marked peripheral rim-like enhancement with internal hypointensity on longer delayed MRI

OBJECTIVES

To obtain specific imaging findings of solitary necrotic nodule of the liver (SNNL) using longer delayed contrast-enhanced MRI and compare them with those of three mimic hepatic diseases.

METHODS

Sixteen patients with SNNL underwent plain and contrast-enhanced triphasic CT and multiphasic MRI with delayed time prolonged to 2 h after contrast bolus injection. Twenty-three patients with mimic lesions including seven with eight HCCs, five with five iCCs and 11 with metastatic lesions served as the control group. Those patients also received plain and multiphasic contrast-enhanced MRI. Imaging features of lesions such as peripheral wash-out time were evaluated.

RESULTS

Among the 16 SNNLs, with a prolonged delayed MRI time, the enhancement degree of tumour periphery increased gradually. When it was up to 1 h, all lesions represented moderate/marked peripheral enhancement with internal hypointensity. However, the peripheral wash-out in seven HCCs (87.5%) and all metastatic lesions except three appeared at 10 or 15 min, one iCC (20%) at 30 min and the other lesions at 1 h.

CONCLUSIONS

Longer MRI with a delayed time of 1-2 h may be useful in diagnosis SNNL, revealing the specific imaging characteristic of SNNL as pronounced peripheral enhancement with internal hypointensity.

KEY POINTS

• Longer delayed MRI plays an important role in the diagnosis of SNNL. • Characteristic imaging feature of SNNL is pronounced peripheral enhancement with internal hypointensity. • Periphery wash-out time can differentiate SNNL from mimic diseases. • Imaging findings of SNNL on routine CT and MRI are unspecific.

Pediatric Endobronchial Inflammatory Myofibroblastic Tumor: A Case Report and Review of the Literature

Inflammatory myofibroblastic tumor (IMT) belongs to the group of soft tissue tumor and could occur at any anatomical site from the central nervous system to gastrointestinal tract. The lung and abdomen are commonly affected sites, however, pulmonary IMT is predominantly located within the parenchyma rather than presenting as endobronchial lesion. IMTs may occur in any age group, but they are observed most commonly in children and adolescents. Here, we present a case of IMT arising from the left main stem bronchus in a 10-year-old girl.

Imaging of childhood inflammatory myofibroblastic tumor

BACKGROUND

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

A case report of an inflammatory myofibroblastic tumor of the neck: A focus on the computed tomography and magnetic resonance imaging findings

Inflammatory myofibroblastic tumors (IMTs) of the neck are rare, with only a few patients reported in the literature. The present study discusses the clinical manifestations, radiographic characteristics and management of these tumors, with a focus on imaging modalities. A case of IMT of the neck is presented and the associated literature is reviewed. In total, seven patients in seven English-language studies, including the present case, and one patient in one Chinese-language study were found. On CT scans, all tumors appeared as soft-tissue densities. Upon magnetic resonance imaging (MRI), all tumors displayed a heterogeneous hypointense-isointense signal on T1-weighted sequences and an isointense-hyperintense signal on T2-weighted sequences. All tumors showed enhancement on enhanced CT and MR images. The imaging features of the neck IMTs can be summarized as follows: i) When enhanced, the tumor displays enhancement on CT and MR images; ii) MRI is superior to CT scans in the differential diagnosis of this disease; iii) in general, the lesion displays a hypointense-isointense signal on T1-weighted sequences and an isointense-hyperintense signal on T2-weighted sequences; iv) due to the fibrous tissue in the tumor, delayed enhancement may be observed on gadolinium-enhanced MR images; and v) due to its benign or intermediate features, the tumor is usually a well-defined mass.

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.

Primary lung and large airway neoplasms in children: current imaging evaluation with multidetector computed tomography

Multidetector computed tomography (MDCT) offers an important noninvasive imaging modality for confirmation and further characterization of primary lung and large airway neoplasms encountered in pediatric patients. Children represent a unique challenge in imaging, not only because of unique patient factors (eg, inability to follow instructions, motion, need for sedation) but because of the technical factors that must be optimized to reduce radiation dose. This article reviews an MDCT imaging algorithm, up-to-date imaging techniques, and clinical applications of MDCT for evaluating benign and malignant primary neoplasms of lung and large airway in infants and children.

Inflammatory myofibroblastic tumor of the lung: a rare cause of atelectasis in children

Although rare, inflammatory myofibroblastic tumor is the most common primary lung mass in children. We report the case of an 11-year-old boy investigated for persistent cough and dyspnea with complete left lung atelectasis mimicking pneumonia. CT and MRI showed an endobronchial mass of the left main bronchus. The boy underwent endoscopic resection of the tumor and histology was in favor of an inflammatory myofibroblastic tumor of the lung. This diagnosis should be suspected in children with recurrent pneumonia. The prognosis is good after complete resection.