Inflammatory myofibroblastic tumors of the pancreas in children: A case report and literature review

Inflammatory Myofibroblastic Tumor of the Esophagus and Stomach Successfully Treated With ALK Inhibitor in a Pediatric Patient: A Case Report and Concise Review of Literature

An inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal neoplasm of borderline malignant potential. Nearly half of all IMTs have rearrangement of anaplastic lymphoma kinase (ALK) locus on chromosome 2p23 which can be treated with targeted therapy. Herein, we describe an unusual presentation of IMT involving an anatomical region rarely implicated in this disease process. A 15-year-old male patient came to the ER with dysphagia and coffee ground emesis. On esophagogastroscopy, a nodular luminal obstructing 30 × 50 mm mass in the lower esophagus was found, which was continuous with a large, partially circumferential gastric mass extending from the mid-body to the proximal antrum. Biopsies from esophageal and gastric masses revealed submucosal lesions composed of cytologically bland spindle and epithelioid cells, intermingled with inflammatory infiltrate, for which several immunohistochemical (IHC) stains were performed. The molecular study demonstrated ATIC::ALK fusion. Based on morphological, IHC, and molecular study findings, the diagnosis of ALK-positive IMT was rendered. Because surgical excision was deemed infeasible, the patient was started on ALK-inhibiting therapy with crizotinib. The patient responded well with no evidence of residual or recurrent disease on follow-up imaging or surveillance esophagogastroduodenoscopy. Crizotinib was ultimately discontinued after 10 months of therapy, and the patient continues to undergo surveillance imaging for monitoring of disease burden.

Aggressive Inflammatory Myofibroblastic Tumor of Distal Pancreas: A Diagnostic and Surgical Challenge

An inflammatory myofibroblastic tumor (IMT) is a rare soft tissue neoplasm of unknown etiology. It is a slow-growing tumor of borderline malignant potential. Distant metastases and recurrence after complete excision are rare. Establishing a preoperative diagnosis is difficult because of its nonspecific clinic-radiological features. Although the majority of cases have been reported in the lungs, it can affect any part of the body. The pancreatic inflammatory myofibroblastic tumor is very rare and only 26 cases have been reported in the medical literature. These tumors mostly arise from the head of the pancreas, whereas occurrence in the body or tail region is rather unusual. Here, we report a case of a 55-year-old male patient with a locally advanced inflammatory myofibroblastic tumor arising from the pancreatic tail. Complete excision of tumor required multi-visceral resection (distal pancreaticosplenectomy with jejunal and colonic segmental resection). The diagnosis of inflammatory myofibroblast tumor was made on the basis of histopathology and immunohistochemistry.

Paediatric Gastrointestinal, Hepatic and Pancreatic Inflammatory Myofibroblastic Tumours, A Single Centre Experience

ABSTRACT

Inflammatory myofibroblastic tumours (IMTs) are rare soft tissue tumours. Reports of gastrointestinal tract, liver and pancreas tumours are limited. The objective of this study is to identify presenting features, contributing prognostic / etiological factors and any variability in outcomes in the context of different historical treatments. We retrospectively reviewed the records of seven children treated at our hospital between 2006 and 2019 and assessed the demographic, presentation, treatment, immunohistochemistry, and outcomes of their tumours. Age range at presentation was 4 months-15 years with a male predominance. Presentations were typically due to local mass effect or incidental discovery. Systemic symptoms were rare. Outcomes were good with six out of seven stable or in remission irrespective of treatment. Surgical resection where possible is the treatment of choice. Medical therapy had good outcomes with chemotherapy acting as first line treatment when required. The only negative prognostic factor identified was local spread at the time of presentation.

Solid pancreatic masses in children: A review of current evidence and clinical challenges

Pancreatic tumors in children are infrequently encountered in clinical practice. Their non-specific clinical presentation and overlapping imaging characteristics often make an accurate preoperative diagnosis difficult. Tumors are categorized as epithelial or non-epithelial, with epithelial tumors further classified as tumors of the exocrine or endocrine pancreas. Although both are tumors of the exocrine pancreas, solid pseudopapillary neoplasm is the most prevalent solid pancreatic tumor in children, while pancreatoblastoma is the most common malignant tumor. Insulinoma is the most common pediatric pancreatic tumor of the endocrine pancreas. Malignant tumors require a complete, often radical, surgical resection. However, pancreatic parenchyma-sparing surgical procedures are utilized for benign tumors and low-grade malignancy to preserve gland function. This review will discuss the epidemiology, pathophysiology, clinical and diagnostic characteristics, and management options associated with both common and rare solid pancreatic masses in children. We will also discuss current challenges encountered in their evaluation and treatment.

Pancreatic Masses in Children and Young Adults: Multimodality Review with Pathologic Correlation

Masses and masslike lesions of the pancreas are uncommon in the pediatric population. However, owing to overlapping clinical and imaging features, it can be challenging to differentiate the various causes of pediatric pancreatic masses at initial patient presentation. Clinical data such as patient age, signs and symptoms at presentation, laboratory test results, and potential underlying cancer predisposition syndrome can be helpful when formulating a differential diagnosis. US may be the first imaging study to depict a pancreatic mass in a child, as this examination is frequently performed in children with nonspecific abdominal signs and symptoms because of its wide availability and relatively low cost and the lack of a need for sedation or anesthesia. CT or MRI is typically required for more thorough characterization of the mass and surgical planning. Complete characterization of pancreatic masses includes assessment of vascular involvement, local invasion, and extrapancreatic spread of tumor. The authors provide an up-to-date comprehensive review of the clinical manifestations, histopathologic features, and imaging findings of primary and secondary tumors of the pancreas in children and young adults. Advances in imaging, current prognostic information, and treatment paradigms also are highlighted. Finally, nontumorous masslike lesions of the pediatric pancreas, including vascular malformations, cystic disorders (eg, von Hippel-Lindau syndrome, cystic fibrosis), intrapancreatic accessory spleen, and autoimmune pancreatitis, are discussed. Online supplemental material is available for this article. ^©RSNA, 2021.

Inflammatory myofibroblastic tumor of the pancreatic neck: A case report and review of literature

BACKGROUND

Pancreatic inflammatory myofibroblastic tumor (IMT) is a relatively rare disease that is often confused with pancreatic cancer or pancreatic neuroendocrine tumors. The histological features of IMTs show that tissue from this type of tumor contains an intermingling of fibroblast and myofibroblast proliferation, accompanied by a varying degree of inflammatory cell infiltration.

CASE SUMMARY

The management of an IMT occurring at the neck of the pancreas is presented in this paper. A 66-year-old female patient was diagnosed with a pancreatic neck mass after a series of tests. The patient underwent enucleation of the pancreatic neck tumor after a pathological diagnosis of IMT. Previous research on the clinical features, pathological diagnosis and treatment of pancreatic IMTs was reviewed. Compared with previous reports, this is a unique case of enucleation of a pancreatic IMT.

CONCLUSION

The enucleation of pancreatic IMTs may be a safe and efficient surgical method for managing such tumors with a better prognosis. Further cases are required to explore surgical measures for pancreatic IMTs.

Calcifying fibrous pseudotumor in the pelvic cavity: A case report and review of the literature

Calcifying fibrous pseudotumors (CFPs) are rare benign lesions mostly occurring in the limbs, necks and gastrointestinal tracts of young adults. In the present study, we report the first known case of a pelvic CFP in China in a 67-year-old male patient. The solitary tumor had an extremely regular shape and was in the vicinity of the sigmoid colon. Surgical resection was performed and the tumor was histologically diagnosed as CFP. We reviewed 64 cases of CFPs and discussed the clinical features of this disease in China and other countries. We found that the CFPs were most common in patients aged 18-60 and often had no obvious symptoms. They were immunoreactive for vimentin and factor XIIIa, while negative for CD117 and S100. In China, CFPs were mostly identified in the stomach, possibly associated with Chinese eating. The pathogenesis of this disease remains unclear. More research is needed to confirm the present results.

A Pancreatic Inflammatory Myofibroblastic Tumor with Spontaneous Remission: A Case Report with a Literature Review

The inflammatory myofibroblastic tumor (IMT) is a rare tumor that can develop in any systemic organ. Its features are generally benign, but it often resembles malignancies and is treated surgically. Our patient was an 82-year-old female complaining of abdominal discomfort. Computed tomography demonstrated a 5 cm, ill-enhanced mass at the pancreas head. Upper gastrointestinal endoscopy revealed a duodenal submucosal tumor with apical erosion. Endoscopic ultrasonography (EUS) demonstrated a heterogeneous, low-echoic pancreas mass without clear margins. Fine-needle aspiration biopsy (FNAB) demonstrated spindle myofibroblastic tissues with lymphoplasmacyte and eosinophil infiltration, confirming an IMT diagnosis. Surprisingly, the tumor spontaneously regressed in one month without medication. Histological diagnosis using EUS-FNAB is essential for the rare pancreatic solid tumor like IMT.

Inflammatory myofibroblastic tumor of the pancreas in a dog

A large, ill-defined, firm, multinodular mass involving the pancreas was confirmed on postmortem examination of a 5-y-old, male Rottweiler that died following acute respiratory distress syndrome, after a period of anorexia and lethargy. Histologically, the mass consisted of plump spindle cells admixed with a variable number of macrophages, lymphocytes, plasma cells, and neutrophils. Foci of coagulative necrosis and hemorrhage were also observed. Spindle cells strongly reacted to antibodies against vimentin, α-smooth muscle actin, and calponin, whereas desmin was expressed only mildly and focally. Pan-cytokeratin, KIT, glial fibrillary acidic protein, and S100 protein were nonreactive. Variable numbers of MAC 387-positive cells, CD3+ lymphocytes, and numerous blood vessels were also detected throughout the mass. Histologic and IHC findings were consistent with a diagnosis of inflammatory myofibroblastic tumor of the pancreas.

Recurrent inflammatory myofibroblastic tumour of the lung: FDG PET/CT scan findings

Inflammatory myofibroblastic tumour (IMT) is a rare neoplasm, occurring most often in children and young adults. IMTs have intermediate biological behaviour with the chance of local invasion, recurrence and even distant metastasis. Wide range of clinical presentations makes the precise diagnosis of IMT more challenging. The best method for definitive diagnosis is tissue biopsy and newer imaging modalities including fleurodeoxyglucose (FDG) positron emission tomography (PET)/CT are useful tools in detection of disease recurrence or distant metastasis. Complete surgical resection is the best-known treatment for this tumour. Here we are presenting an IMT case in a 12-year-old girl in which her recurrent pulmonary IMT was diagnosed based on FDG PET/CT findings and referred for further salvage treatment. Overall imaging modalities are not specific, but PET/CT scan can be useful tool for evaluation of IMT regarding initial staging and restaging to assess treatment response and recurrence.

Nonepithelial Neoplasms of the Pancreas, Part 2: Malignant Tumors and Tumors of Uncertain Malignant Potential From the Radiologic Pathology Archives

Almost all neoplasms of the pancreas are derived from pancreatic epithelial components, including the most common pancreatic mass, primary pancreatic ductal adenocarcinoma (PDAC). Nonepithelial neoplasms comprise only 1%-2% of all pancreatic neoplasms. Although some may arise directly from intrapancreatic elements, many originate from mesenchymal, hematopoietic, or neural elements in the retroperitoneal peripancreatic space and grow into the pancreas. Once these tumors reach a certain size, it can be challenging to identify their origin. Because these manifest at imaging as intrapancreatic masses, awareness of the existence and characteristic features of these nonepithelial neoplasms is crucial for the practicing radiologist in differentiating these tumors from primary epithelial pancreatic tumors, an important distinction given the vastly different management and prognosis. In part 1 of this article, the authors reviewed benign nonepithelial neoplasms of the pancreas. This article focuses on malignant nonepithelial neoplasms and those of uncertain malignant potential that can be seen in the pancreas. The most common malignant or potentially malignant nonepithelial pancreatic tumors are of mesenchymal origin and include soft-tissue sarcomas, solitary fibrous tumor, and inflammatory myofibroblastic tumor. These tumors commonly manifest as large heterogeneous masses, often containing areas of necrosis and hemorrhage. The clinical features associated with these tumors and the imaging characteristics including enhancement patterns and the presence of fat or calcification help distinguish these tumors from PDAC. Hematopoietic tumors, including lymphoma and extramedullary plasmacytoma, can manifest as isolated pancreatic involvement or secondarily involve the pancreas as widespread disease. Hyperenhancing paragangliomas or hypervascular metastatic disease can mimic primary pancreatic neuroendocrine tumors or vascular anomalies.