Effectiveness of Crizotinib for Inflammatory Myofibroblastic Tumor with ALK mutation

Pediatric skull inflammatory myofibroblastic tumor: a rare case report and literature review

Inflammatory myofibroblastic tumors (IMTs) represent rare neoplasms, particularly infrequent in the pediatric skull. We present a novel case of a newborn male with a 5 cm right temporal mass and discuss current diagnostic and treatment options for IMTs. A multidisciplinary effort to surgically remove the lesion was successful, and the patient's skull defect healed without neurological deficits. The etiology of IMTs remains elusive, with proposed associations with chromosomal mutations in the anaplastic lymphoma kinase (ALK) gene. Surgical excision remains the primary treatment for IMTs. Promising pharmacological treatments, like Crizotinib, warrant further research into understanding potential alternatives in IMT management.

Inflammatory myofibroblastic tumor from molecular diagnostics to current treatment

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm with intermediate malignancy characterized by a propensity for recurrence but a low metastatic rate. Diagnostic challenges arise from the diverse pathological presentation, variable symptomatology, and lack of different imaging features. However, IMT is identified by the fusion of the anaplastic lymphoma kinase (ALK) gene, which is present in approximately 70% of cases, with various fusion partners, including ran-binding protein 2 (RANBP2), which allows confirmation of the diagnosis. While surgery is the preferred approach for localized tumors, the optimal long-term treatment for advanced or metastatic disease is difficult to define. Targeted therapies are crucial for achieving sustained response to treatment within the context of genetic alteration in IMT. Crizotinib, an ALK tyrosine kinase inhibitor (TKI), was officially approved by the US Food and Drug Administration (FDA) in 2020 to treat IMT with ALK rearrangement. However, most patients face resistance and disease progression, requiring consideration of sequential treatments. Combining radiotherapy with targeted therapy appears to be beneficial in this indication. Early promising results have also been achieved with immunotherapy, indicating potential for combined therapy approaches. However, defined recommendations are still lacking. This review analyzes the available research on IMT, including genetic disorders and their impact on the course of the disease, data on the latest targeted therapy regimens and the possibility of developing immunotherapy in this indication, as well as summarizing general knowledge about prognostic and predictive factors, also in terms of resistance to systemic therapy.

Anaplastic lymphoma kinase inhibitors-a review of anticancer properties, clinical efficacy, and resistance mechanisms

Fusions and mutations of anaplastic lymphoma kinase (ALK), a tyrosine kinase receptor, have been identified in several neoplastic diseases. Rearranged ALK is a driver of tumorigenesis, which activates various signaling pathway associated with proliferation and survival. To date, several agents that target and inhibit ALK have been developed. The most studied ALK-positive disease is non-small cell lung cancer, and three generations of ALK tyrosine kinase inhibitors (TKIs) have been approved for the treatment of metastatic disease. Nevertheless, the use of ALK-TKIs is associated with acquired resistance (resistance mutations, bypass signaling), which leads to disease progression and may require a substitution or introduction of other treatment agents. Understanding of the complex nature and network of resistance mutations may allow to introduce sequential and targeted therapies. In this review, we aim to summarize the efficacy and safety profile of ALK inhibitors, describe off-target anticancer effects, and discuss resistance mechanisms in the context of personalized oncology.

Inflammatory myofibroblastic tumors: recent progress and future of targeted therapy

An inflammatory myofibroblastic tumor is a rare component of bone and soft-tissue sarcomas that has distinct pathological features as a lymphoplasmacytic inflammatory infiltrate. As is the case for other non-small round cell sarcomas, surgical resection remains the standard treatment strategy for inflammatory myofibroblastic tumors, but recurrence is possible. Concerning systemic therapy, the available data for conventional chemotherapy (such as those of doxorubicin-based regimens) are limited, and case reports of anti-inflammatory inflammatory myofibroblastic tumor treatments describe some degree of symptom relief and efficacy against tumor progression. However, as more information about cancer genomics accumulates, the potential for molecularly targeted therapies for inflammatory myofibroblastic tumors has become more promising. Approximately half of inflammatory myofibroblastic tumors harbor anaplastic lymphoma kinase (ALK) fusion genes, and the other half could have potentially targetable fusion genes or mutations such as ROS1, NTRK and RET; case reports demonstrating the clinical efficacy of treatments targeted to inflammatory myofibroblastic tumor have been published, as have several prospective clinical trials. Few drugs are approved for the treatment of inflammatory myofibroblastic tumor, and most of them were approved for tumor-agnostic indications. Drugs that could be used for pediatric indications and dosing in inflammatory myofibroblastic tumor have also not been established. To provide effective targeted therapy for rare diseases such as inflammatory myofibroblastic tumor, it is necessary to obtain clinical evidence by designing and performing clinical trials and to find a path toward regulatory approval.

Inflammatory myofibroblastic tumor of the lung involving the central nervous system in pediatric patients

INTRODUCTION

The inflammatory myofibroblastic tumor (IMT) is a very rare lesion with an incidence of less than 0.1% of total neoplasms and with main affection in the lungs. Involvement in the central nervous system is extremely rare, but with a much more aggressive course than IMT diagnosed in the rest of the body. We report the 2 cases presented in our neurosurgery department to date; both were treated satisfactorily without intercurrences in 10 years of follow-up.

HISTORICAL BACKGROUND

The World Health Organization described the IMT as a distinctive lesion composed of myofibroblastic spindle cells accompanied by an inflammatory infiltrate of plasma cells, lymphocytes, and eosinophils.

CLINICAL PRESENTATION

Clinical manifestations of patients with CNS IMT vary and may consist of headache, vomiting, seizures, and blindness. Seizures are the most common symptom in patients with focal lesions.

DIAGNOSIS

The true origin of this entity remains to be elucidated, but to date, etiologies ranging from chromosomal alterations to autoimmune or postinfectious mechanisms have been described. Due to its rarity and non-specificity in imaging, the final diagnosis of IMT in the brain parenchyma relies on pathological examination.

MANAGEMENT

Treatment options are controversial and include total or subtotal removal, high-dose steroids, and radiation therapy. In the last decade, the development of ALK Tyrosine Kinase Inhibitors allows the possibility of chemotherapy in those patients harboring ALK mutations.

CONCLUSION

IMT is a rare tumor that can exceptionally be found in the CNS. The cause is still unknown although the different studies focus on a neoplastic origin. The diagnosis is based in the use of different modalities of imaging and with histological confirmation. Optimal management is gross total resection whenever possible, is the only established curative treatment. Further research with longer follow-up is needed to clarify the natural history of this rare tumor.

Infantile Inflammatory Myofibroblastic Tumor of Spleen

Background: Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm with unknown etiology and recurrent potential. They are widely reported in children and young adults. Nearly 50% of inflammatory myofibroblastic tumor harbor rearrangement in anaplastic lymphoma kinase (ALK) gene with the majority expressing ALK protein. ALK-negative IMTs harbor alteration in ROS1 gene in a subset of cases. Few reports have shown association of IMT with Epstein-Barr virus (EBV). Case report: We report a case of IMT of the spleen in an 18-month-old infant presenting with abdominal distention and failure to thrive. Workup for ALK-1, ROS1, and EBV small-encoded RNA in-situ hybridization using immunohistochemistry was negative. Conclusions: IMT can arise in an infant spleen.

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.

Crizotinib in Sarcomatous Malignancies Harboring ALK Fusion With a Definitive Partner(s): Response and Efficacy

Sarcoma or sarcomatoid malignancies are a set of mesenchymal-origin malignancies with vast heterogeneity in clinical and molecular characteristics. Anaplastic lymphoma kinase (ALK) is a tyrosine kinase oncoprotein expressed by several tumors, including sarcomas. Crizotinib is an effective ALK inhibitor. In this review paper, we summarized findings from the literature regarding the use of crizotinib for the treatment of sarcoma and sarcomatoid malignancies harboring ALK fusions with definitive partners (with the given gene(s) name) from the years 2010 to 2021.One hundred and four articles were retrieved and after exclusion, 28 studies containing 33 patients were finally selected. All 33 patients were treated with crizotinib. Among the 33 cases, 19 were adult patients, 11 were pediatric patients, and 3 cases did not have data on age and/or gender. Most cases had a primary abdominal lesion (16/30), followed by thoracic (10/30), trunk (3/30), retroperitoneal (1/30), and one case of right medial thigh (case 7). Stage IV disease was reported in 76.7% (23/30) of patients. The objective response rate and disease control rate was 86.7% (26/30) and 96.7% (29/30), respectively, which were assessed on average of 8 weeks after crizotinib initiation. Rapid improvement of symptoms was observed within one to two weeks in some cases including patients with extensive diseases or poor performance. There was no difference in crizotinib response between pediatrics and adult cases. Crizotinib is effective; however, surgery remains the mainstay of therapy, with newer evidence showing concurrent crizotinib with surgery conferring long-term overall survival. However, we should still be cognizant of the heterogeneous landscape of crizotinib efficacy and its associated fatal adverse events.

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.

Development of a novel ALK rearrangement screening test for non-small cell lung cancers

Approximately 5–7% of non–small cell lung cancer (NSCLC) cases harbor an anaplastic lymphoma kinase (ALK) fusion gene and may benefit from ALK inhibitor therapy. To detect ALK fusion genes, we developed a novel test using reverse transcription polymerase chain reaction (RT-PCR) for the ALK kinase domain (KD). Since ALK expression is mostly silenced in the adult with the exception of neuronal tissue, the normal lung tissue, mesothelial lining, and inflammatory cells are devoid of ALK transcript, making ALK KD RT-PCR an ideal surrogate test for ALK fusion transcripts in lung or pleural effusion. The test was designed with a short PCR product (197 bp) to work for both malignant pleural effusion (MPE) and formalin-fixed, paraffin-embedded (FFPE) NSCLC samples. Using ALK IHC as a reference, the sensitivity of the test was 100% for both MPE and FFPE. The specificity was 97.6% for MPE and 97.4% for FFPE. Two false positive cases were found. One was a metastatic brain lesion which should be avoided in the future due to intrinsic ALK expression in the neuronal tissue. The other one resulted from ALK gene amplification. Due to potential false positivity, subsequent confirmation tests such as fluorescence in situ hybridization or multiplex PCR would be preferable. Nevertheless, the test is simple and inexpensive with no false negativity, making it a desirable screening test. It also offers an advantage over multiplex RT-PCR with the capability to detect novel ALK fusions. Indeed through the screening test, we found a novel ALK fusion partner (sperm antigen with calponin homology and coiled-coil domains 1 like gene, SPECC1L) with increased sensitivity to crizotinib in vitro. In summary, a novel RNA-based ALK KD analysis was developed for ALK rearrangement screening in MPE and FFPE specimens of NSCLC. This simple inexpensive test can be implemented as routine diagnostics.

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.

Inflammatory Myofibroblastic Tumor: A Rare Presentation and an Effective Treatment with Crizotinib

Inflammatory myofibroblastic tumor (IMT) is a rare entity of neoplastic origin. It usually occurs in children and adolescents and most commonly involves pulmonary and gastrointestinal sites. Here, the authors present two cases; one is the nine months old boy with a subcutaneous IMT in the left temporal region that was treated successfully with surgical resection. To the best of our knowledge, this is the first reported case of a subcutaneous IMT in this particular region. The second is an eight years old girl with an IMT of the right hemi-pelvis. The mass had complete surgical excision with clear margins and no residual disease. She was kept on regular follow-up with ultrasound abdomen. However, her disease relapsed with the appearance of lesions in right iliac fossa, right ovary, and liver. Biopsy of the relapsed abdominal mass confirmed ALK-positive IMT. She was treated with ALK inhibitor Crizotinib. She was monitored with regular blood complete picture, hepatic and renal function test, and ultrasound abdomen. Her lesions started regressing within one month, and she achieved complete remission after 6 months of treatment.

ALK-1-positive inflammatory myofibroblastic tumor of the thyroid complicated by Hashimoto's thyroiditis: report of a rare case and a literature review

BACKGROUND

Inflammatory myofibroblastic tumors (IMTs) of the thyroid are extremely rare soft-tissue tumors. In the literature, IMTs are sometimes called plasma cell granulomas (PCGs) or inflammatory pseudotumors, which often causes ambiguity. To date, 17 cases of PCGs and five cases of thyroid IMTs have been reported. These cases reveal that IMTs of the thyroid are often negative for the anaplastic lymphoma kinase (ALK-1) gene. To provide further information on this rare lesion, we present a case of an ALK-1-positive thyroid IMT and a review of IMTs of the thyroid.

CASE PRESENTATION

A 34-year-old Chinese woman presented with a painless neck mass that had persisted for over a month. Ultrasonography revealed a 4.28 × 2.53 cm² hypoechoic mass, in the left lobe of the thyroid gland. Serum levels of thyroglobulin and anti-thyroglobulin antibodies were high. Subsequently, left lobectomy was performed. Macroscopically, the lesion was a gray-brown nodular mass with a partial envelope. Histologically, two different lesion types were observed. The first lesion showed classic spindle cell proliferation, with spindle cells arranged in fascicles, accompanied by mature inflammatory cells. The other lesion showed a large number of infiltrating lymphocytes, with lymphoid follicles in the remaining thyroid gland, which was atrophic. Immunohistochemical staining showed that the spindle cells were negative for CK19, CyclinD1, Gelectin-3, EMA, CD34, S100, Bcl-2, and STAT-6, but strongly positive for ALK-1, vimentin, and TTF1. CK was focally expressed, and the Ki-67 index was 5%. A diagnosis of IMT was proposed according to immunohistochemical findings and morphology. Hashimoto's thyroiditis was confirmed according to serum levels of thyroglobulin and anti-thyroglobulin antibodies and morphology. The patient did not receive adjuvant therapy. She remained alive without disease recurrence for 10 months after lobectomy.

CONCLUSIONS

IMTs should be considered in the diagnosis when spindle cell proliferation accompanied by mature inflammatory cells is observed, spindle cells are mildly atypical, and myofibroblast differentiation is present in the thyroid. A uniform diagnostic term is crucial to avoid ambiguity. Clinicians and pathologists should be aware of the necessity for long-term follow-up, especially in ALK-positive cases. The therapeutic potential of ALK-1 positivity should be explored further.