Inflammatory Myofibroblastic Tumor: A Multi-Institutional Study from the Pediatric Surgical Oncology Research Collaborative

Management of undifferentiated embryonal sarcoma of the liver: A Pediatric Surgical Oncology Research Collaborative study

BACKGROUND

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare tumor for which there are few evidence-based guidelines. The aim of this study was to define current management strategies and outcomes for these patients using a multi-institutional dataset curated by the Pediatric Surgical Oncology Research Collaborative.

METHODS

Data were collected retrospectively for patients with UESL treated across 17 children's hospitals in North America from 1989 to 2019. Factors analyzed included patient and tumor characteristics, PRETEXT group, operative details, and neoadjuvant/adjuvant regimens. Event-free and overall survival (EFS, OS) were the primary and secondary outcomes, respectively.

RESULTS

Seventy-eight patients were identified with a median age of 9.9 years [interquartile range [IQR): 7-12]. Twenty-seven patients underwent resection at diagnosis, and 47 patients underwent delayed resection, including eight liver transplants. Neoadjuvant chemotherapy led to a median change in maximum tumor diameter of 1.6 cm [IQR: 0.0-4.4] and greater than 90% tumor necrosis in 79% of the patients undergoing delayed resection. R0 resections were accomplished in 63 patients (81%). Univariate analysis found that metastatic disease impacted OS, and completeness of resection impacted both EFS and OS, while multivariate analysis revealed that R0 resection was associated with decreased expected hazards of experiencing an event [hazard ratio (HR): 0.14, 95% confidence interval (CI): 0.04-0.6]. At a median follow-up of 4 years [IQR: 2-8], the EFS was 70.0% [95% CI: 60%-82%] and OS was 83% [95% CI: 75%-93%].

CONCLUSION

Complete resection is associated with improved survival for patients with UESL. Neoadjuvant chemotherapy causes minimal radiographic response, but significant tumor necrosis.

Positron emission tomography in the diagnosis and management of primary pediatric lung tumors

Primary pediatric lung tumors are uncommon and have many overlapping clinical and imaging features. In contrast to adult lung tumors, these rare pediatric neoplasms have a relatively broad histologic spectrum. Informed by a single-institution 13-year retrospective record review, we present an overview of the most common primary pediatric lung neoplasms, with a focus on the role of positron emission tomography (PET), specifically 18F-fluorodeoxyglucose (FDG) PET and 68Ga-DOTATATE PET, in the management of primary pediatric lung tumors. In addition to characteristic conventional radiographic and cross-sectional imaging findings, knowledge of patient age, underlying cancer predisposition syndromes, and PET imaging features may help narrow the differential. While metastases from other primary malignancies remain the most commonly encountered pediatric lung malignancy, the examples presented in this pictorial essay highlight many of the important conventional radiologic and PET imaging features of primary pediatric lung malignancies.

Inflammatory myofibroblastic tumor of the bladder turn malignant: A case report

INTRODUCTION AND IMPORTANCE

Inflammatory myofibroblastic tumor (IMT) of the bladder is a rare sight, which can be distinguished by the proliferation of spindle cells and the presence of a persistent chronic inflammatory infiltrate. IMT is usually benign, but in a few cases it has a tendency for malignant transformation and metastases.

CASE PRESENTATIONS

A 30-year-old male with a history of recurrent hematuria. His initial symptoms was unfrequent painless hematuria. Abdomen multislice computerized tomography (MSCT) with contrast shows an enhancing solid mass with necrotized center measuring +/- 12.9 × 16.5 × 18.9 cm and extending from cavum pelvis to cavum abdomen. Cystectomy and bilateral ureterocutaneostomy were performed. The histology report found an IMT with mitotic cells, a necrotic region, and a positive ki67, which suggest the tumor's malignant transformation. Unfortunately, the patient's overall condition continued to deteriorate, and he passed away seven days after hospital discharge.

CLINICAL DISCUSSIONS

IMT is comprised of spindel cells and inflammatory cells. IMT might become aggressive locally, recurring, or progress to malignancy. Fifty percent of IMTs are caused by rearrangements of the anaplastic lymphoma kinase (ALK) gene on chromosome 2p23, resulting in ALK-1 overexpression. A change from uniform spindled cells to atypical polygonal cells or plump cells with oval vesicular nuclei, prominent nucleoli, and mitoses is indicative of malignant transformation.

CONCLUSION

This case emphasizes the importance of continuous monitoring and raising awareness about the possibility of malignant transformation of IMT. Understanding the characteristics of the findings could result in better decision-making and outcomes.

Inflammatory myofibroblastic tumor of the submandibular gland Harboring MSN-ALK gene fusion: A case report and literature review

Inflammatory myofibroblastic tumors (IMTs) are rare lesions with distinct clinical, pathological, and molecular characteristics. IMTs typically arise in the abdominal soft tissues, including the mesentery, omentum, and retroperitoneum, followed by the lungs and mediastinum, and usually affect both children and young adults. Herein, we present a rare case of an IMT in the submandibular gland of a 47-year-old male patient. Microscopically, the tumor displayed an infiltrative growth pattern with diffuse glandular tissue destruction. Their backgrounds revealed characteristic spindles and inflammatory cells. Immunohistochemistry revealed positivity for anaplastic lymphoma kinase (ALK), smooth muscle actin, and calponin in neoplastic cells. The inflammatory cells and some neoplastic cells were positive for CD68. In contrast, negative staining for cytokeratin, desmin, and CD30 was observed. Furthermore, fluorescence in situ hybridization revealed ALK gene rearrangements, and next-generation sequencing detected a moesin (MSN)-ALK gene fusion. This case highlights a rare and unique occurrence of IMT originating from the submandibular gland, which exhibited an MSN-ALK gene fusion.

Infarction of Paratesticular Inflammatory Myofibroblastic Tumor Mimicking Testicular Torsion

This report describes a 14-year-old male with a rare paratesticular inflammatory myofibroblastic tumor that presented atypically with acute unilateral scrotal pain and swelling. This presentation, which raised suspicion for testicular torsion, contrasts with the typical presentation of a slow-growing scrotal mass. Scrotal exploration revealed an infarcted right testis, demonstrating this locally aggressive tumor can undergo vascular invasion and occlude testicular blood supply. Thus, inflammatory myofibroblastic tumor should be considered in the differential diagnosis when evaluating patients with acute scrotal pain suspicious for testicular infarction.

Increased 68 Ga-FAPI Activity in Hepatic Inflammatory Myofibroblastoma

ABSTRACT

Hepatic inflammatory myofibroblastoma is an uncommon borderline tumor. We present 68 Ga-FAPI PET/CT findings of hepatic inflammatory myofibroblastoma in a 58-year-old man. The rare hepatic inflammatory myofibroblastoma demonstrated intense tracer uptake on 68 Ga-FAPI PET/CT. This case demonstrates the potential value of 68 Ga-FAPI PET/CT for the evaluation of hepatic inflammatory myofibroblastoma.

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.