Anaplastic lymphoma kinase expression in inflammatory pseudotumors

Two cases of inflammatory myofibroblastic tumor treated with targeted drugs: A case report

INTRODUCTION

Inflammatory myofibroblastic tumor (IMT) is a rare invasive soft tissue tumor. Many IMTs are positive for anaplastic lymphoma kinase (ALK) with ALK gene fusion; other gene mutations have also been reported, which indicates a key role for genetic testing and the development of target therapy to optimize treatment strategies.

PATIENT CONCERNS

We report 2 patients who obtained clinical benefits following targeted treatment with ensartinib.

DIAGNOSIS

The first patient was diagnosed as IMT, with TFG-ROS1 fusion gene mutation. The second patient was IMT harboring the ALK-STRN fusion gene mutation.

INTERVENTIONS

We performed gene testing for these 2 patients. According to the test result, both patients received ensartinib 225 mg QD as targeted therapy for a 30-day cycle.

OUTCOMES

The first patient achieved partial remission and maintained a stable state for 14.7 months. The second patient was treated for 10 months and reached complete remission after 5 months and is currently still benefiting from treatment. Treatment-related side effects were mild in both patients.

CONCLUSION

Our cases provided some new insights and approaches for the clinical diagnosis and treatment of IMT.

A diagnostically challenging case of inflammatory myofibroblastic tumor primary to the peritoneum

Introduction

Inflammatory myofibroblastic tumors are difficult to diagnose because of the lack of specific indicators. We describe a diagnostically challenging case of an inflammatory myofibroblastic tumor primary to the peritoneum.

Case presentation

The patient was a 25-year-old male who presented at our hospital with lower abdominal pain. Computed tomography revealed a mass lesion 80 mm in diameter just above the bladder. This was suspected to be a bleeding tumor of the urachus. Since malignancy could not be ruled out, surgery was planned. This revealed a fragile tumor arising from the peritoneum. Following its removal, the tumor was diagnosed by histopathological analysis as an inflammatory myofibroblastic tumor.

Conclusion

We describe a case of inflammatory myofibroblastic tumor primary to the peritoneum diagnosed by histopathology. Inflammatory myofibroblastic tumor should be considered in the differential diagnosis of abdominal wall and anterior bladder tumors.

Mesenchymal tumours of the pleura: review and update

Primary mesenchymal tumours of the pleura are uncommon and can be diagnostically challenging due to their overlapping histopathologic and immunophenotypic features. Herein we discuss selected mesenchymal tumours of the pleura, including solitary fibrous tumour, calcifying fibrous tumour, desmoid fibromatosis, synovial sarcoma, schwannoma, malignant peripheral nerve sheath tumour, inflammatory myofibroblastic tumour, follicular dendritic cell sarcoma, epithelioid hemangioendothelioma, and desmoplastic small round cell tumour. We review their clinicopathologic characteristics, along with an update on the relevant immunohistochemical and molecular features.

Update of Diagnosis and Targeted Therapy for ALK+ Inflammation Myofibroblastic Tumor

OPINION STATEMENT: Inflammatory myofibroblastic tumor (IMT), characterized by intermediate malignancy and a propensity for recurrence, has presented a formidable clinical challenge in diagnosis and treatment. Its pathological characteristics may resemble other neoplasms or reactive lesions, and the treatment was limited, taking chemotherapies as the only option for those inoperable. However, discovering anaplastic lymphoma kinase (ALK) protein expression in approximately 50% of IMT cases has shed light on a new diagnostic approach and application of targeted therapies. With the previous success of combating ALK+ non-small-cell lung cancers with ALK tyrosine kinase inhibitors (TKIs), crizotinib, a first-generation ALK-TKI, was officially approved by the U.S. Food and Drug Administration in 2020, to treat unresectable ALK+ IMT. After the approval of crizotinib, other ALK-TKIs, such as ceritinib, alectinib, brigatinib, and lorlatinib, have proven their efficacy on ALK+ IMT with sporadic case reports. The sequential treatments of targeted therapies in may provide the insight into the choice of ALK-TKIs in different lines of treatment for unresectable ALK+ IMT.

[Receptor tyrosine kinase- fusions in paediatric spindle cell tumors]

Pediatric spindle cell tumors are rare and often difficult to diagnose due to a similar morphology and a non-specific immunohistochemical profile. Genetic characterization of these lesions has been constantly improving, which has led to the identification of new subgroups that were partly included in the WHO classification. Receptor tyrosine kinase fusions play a special role in these tumors and their verification has diagnostic relevance and can be an option for target-oriented therapies. In the case of pediatric spindle cell tumors, genetic fusions form especially with NTRK1‑3, ALK, RET, and ROS1. Overall, pediatric tumors with receptor tyrosine kinase fusions are predominantly low-grade tumors, which are often subdivided into the group of intermediate-malign tumors.

Inflammatory myofibroblastic tumor of the pancreatic neck misdiagnosed as neuroendocrine tumor: A case report

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a relatively rare tumor. The global incidence of IMT is less than 1%. There is no specific clinical manifestation. It usually occurs in the lungs, but the pancreas is not the predilection site.

CASE SUMMARY

We present a case of a male patient, 51 years old, who was diagnosed with a pancreatic neck small mass on ultrasound one year ago during a physical examination. As he had no clinical symptoms and the mass was relatively small, he did not undergo treatment. However, the mass was found to be larger on review, and he was referred to our hospital. Since the primal clinical diagnosis was pancreatic neuroendocrine tumor, the patient underwent surgical treatment. However, the case was confirmed as pancreatic IMT by postoperative pathology.

CONCLUSION

Pancreatic IMT is relatively rare and easily misdiagnosed. We can better under-stand and correctly diagnose this disease by this case report.

Inflammatory Myofibroblastic Tumour of the Urinary Bladder in a Middle-Aged Man-A Case Report of an Unusual Localization of a Rare Tumour

Inflammatory myofibroblastic tumour (IMT) is a rare tumour with an intermediate biological behaviour. It usually occurs in children and adolescents, primarily in the abdomen or lungs. Histopathologically, IMT consists of spindle cells, i.e., myofibroblasts, and a variable inflammatory component. Localization in the urinary bladder is rare. We are presenting a rare case of IMT in the bladder in a middle-aged man treated by partial cystectomy. A 62-year-old man consulted a urologist because of haematuria and dysuric disturbances. A tumorous mass was detected by an ultrasound in the urinary bladder. CT urography described the tumorous mass at the dome of the urinary bladder measuring 2 × 5 cm. A smooth tumorous mass was cystoscopically observed at the dome of the urinary bladder. Transurethral resection of the bladder tumour was performed. Histopathological analysis of the specimen identified spindle cells with a mixed inflammatory infiltrate; immunohistochemical findings showed positivity for anaplastic lymphoma kinase (ALK), smooth muscle actin (SMA) and vimentin. A histopathological diagnosis of IMT was established. It was decided that the patient would undergo a partial cystectomy. A complete excision of the tumour from the dome of the urinary bladder with surrounding healthy tissue was performed. Histopathological and immunohistochemical findings of the sample confirmed the diagnosis of IMT, without the presence of the tumour at the surgical margins. The postoperative course went smoothly. IMT is a rare tumour in adults, especially localised in the urinary bladder. IMT of the urinary bladder is difficult to distinguish from urinary bladder malignancy both clinically and radiologically, as well as histopathologically. If the location and size of the tumour allow it, bladder-preserving surgeries such as partial cystectomy represent a reasonable modality of operative treatment.

Primary inflammatory myofibroblastic tumour of the liver: a clinicopathological and genetic study including a subset with ETV6::NTRK3 fusion

AIMS

Inflammatory myofibroblastic tumour (IMT) is an intermediate neoplasm and rarely occurs in the liver. The aim of this study was to analyse the clinicopathological and genetic features of the largest primary hepatic IMT.

METHODS AND RESULTS

A total of 10 cases were identified (four males and six females aged 1-48 years, median = 35 years) from 2011 to 2021, which accounted for 2.5% of IMTs occurring in all organ systems. Histological findings revealed that myofibroblastic/fibroblastic cells with inflammatory infiltration and focal hypocellularity were observed in three children. Immunostaining showed ALK-diffuse cytoplasmic positive in six cases (six of 10; 60%) and pan-TRK nuclear positive in three cases (three of 10; 30%). Hypercellular pattern was detected in ALK-positive IMTs and obvious collagenous/myxoid matrix was observed in the pan-TRK-positive subgroup. ALK rearrangement was demonstrated in three of five interpretable ALK-positive IMTs by fluorescence in-situ hybridisation (FISH), and one case failed due to poor sample quality. Next-generation sequencing indicated an IMT with TFG::ALK and FCHSD2::ALK fusion and TP53 mutation. ETV6::NTRK3 fusion was confirmed by RT-PCR, but FISH-negative results were found in two of three cases with pan-TRK-positive IMTs. No genetic alteration was detected in one tumour. One patient died 1 year after biopsy, while nine patients survived without evidence of disease in the follow-up surveillance (17-119 months).

CONCLUSIONS

This article describes the first example of primary paediatric hepatic IMTs with ETV6::NTRK3 fusion. Besides the common ALK-positive subgroup, the proportion of NTRK3 fusion is high. Recognising the association between clinicopathological and molecular alterations is critical to accurate diagnosis of hepatic IMTs.

Inflammatory Myofibroblastic Tumour: State of the Art

Simple Summary

Among sarcomas, which are rare cancers, inflammatory myofibroblastic tumors are extremely rare. Unlike other subtypes, this is a largely oncogene-driven neoplasia, and early gene rearrangement identification is important for accurate advanced stage treatment. In this manuscript, we review the clinicopathologic characteristics of this ultra-rare entity, as well as the current treatment landscape, with a particular focus on opportunities provided by tyrosine kinase inhibitors (TKIs).

Abstract

An inflammatory myofibroblastic tumor (IMT) is a neoplasm composed of myofibroblastic and fibroblastic spindle cells accompanied by inflammatory cells, including lymphocytes and eosinophils. It is an ultra-rare tumor, the optimal management of which remains to be defined. Surgery is the treatment of choice for localized tumors. The treatment of advanced disease is not precisely defined. Chemotherapy regimens result in an overall response rate of approximately 50% based on retrospective data. The latest pathophysiological data highlight the role played by tyrosine kinase fusion genes in IMT proliferation. Anaplast lymphoma kinase (ALK) oncogenic activation mechanisms have been characterized in approximately 80% of IMTs. In this context, data regarding targeted therapies are most important. The aims of this article are to review the latest published data on the use of systematic therapy, particularly the use of molecular targeted therapy, and to publish an additional case of an IMT with Ran-binding protein 2 (RANPB2)-ALK fusion showing a long response to a tyrosine kinase inhibitor.

Inflammatory pseudotumor and myofibroblastic inflammatory tumor. Diagnostic criteria and prognostic differences

INTRODUCTION

Inflammatory pseudotumor (IPT) and inflammatory myofibroblastic tumor (IMT) are two very rare entities that were formerly included in the same category; however, today they are considered two different diseases due to the neoplastic origin of the IMT. Our objective is to share our experience in the management of these two types of tumors that we must take into account in the differential diagnosis of pulmonary masses or nodules.

METHODS

Thirteen patients with a pathological diagnosis of IPT and IMT who underwent surgery between 2008 and 2019 were retrospectively studied. We recorded the pre and postoperative information of each one, as well as the survival analysis.

RESULTS

Of the 13 patients, 8 were men and 5 women. The mean age of presentation was 53,5 years. An atypical segmentectomy was performed in 6 patients; a lobectomy was necessary in 6 and a pneumonectomy in 1 case. In all cases a complete resection was achieved. Diagnosis was possible thanks to histology, immunohistochemical (IHQ) and fluorescent in situ hybridization (FISH) techniques determining the expression of IgG4 and the rearrangement of ALK, respectively. After a median follow up of 49 months, we didn't find any loco-regional or distant recurrence in the patients studied.

CONCLUSION

IPT and IMT are rare tumors with a very good prognostic. The diagnosis of both entities is based mainly on specific anatomopathological techniques. Surgery has, in most cases, both a diagnostic and therapeutic role.

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.

Durable Clinical Response to ALK Tyrosine Kinase Inhibitors in Epithelioid Inflammatory Myofibroblastic Sarcoma Harboring PRRC2B-ALK Rearrangement: A Case Report

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal neoplasm and patients with IMT tend to have a favorable outcome after complete surgical resection. However, some tumors of IMT cases have recurred and grown rapidly after successful surgery. Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is a highly aggressive intra-abdominal IMT variant with epithelioid-to-round cell morphology. Currently, no standard therapy exists for recurrent or invasive IMTs and EIMS, but anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) are recommended for those harboring ALK gene rearrangements. We herein report the first case of PRRC2B-ALK fusion associated IMTs with clinical and pathological manifestation matched the diagnosis criteria of EIMS and the durable clinical response of the sequential use of ALK TKIs (crizotinib, alectinib, ceritinib, and lorlatinib). A female patient with EIMS of the greater omentum was suffering from a rapid recurrence after cytoreductive surgery was done. Crizotinib was administered when PRRC2B-ALK fusion was detected, and partial response was achieved. The progression-free survival (PFS) of crizotinib was 5 months. Alectinib was administered based on the results of second next-generation sequencing (NGS) analysis, which identified the secondary mutation ALK R1192P. The best overall response of alectinib treatment was a partial response (PR) and the PFS was 5.5 months. Ceritinib was prescribed as third-line therapy after alectinib resistance with ALK L1196M mutation. PR was achieved and the PFS of ceritinib was 6 months. The patient was taking lorlatinib after ceritinib resistance and achieved a stable disease at 2 months with the PFS more than 5 months. The overall survival was more than two years as of the time of manuscript preparation. We describe an EIMS of greater omentum caused by PRRC2B-ALK fusion gene and showed durable clinical response to the sequential use of ALK TKIs.

Mini-invasive endoscopic approach to tracheal inflammatory myofibroblastic tumor in a young woman: A case report

INTRODUCTION

Inflammatory myofibroblastic tumor (IMT) of the trachea is rare tumor mostly found in children and young adults.

CASE REPORT

We report a case of a 28 year-old woman who presented chronic isolated coughing. Chest CT scan showed a tracheal tumor. Rigid bronchoscopy allowed the complete removal of the tumor, and histology confirmed the diagnosis of IMT. 12 months follow-up found no recurrence.

DISCUSSION

IMT is a rare tumor exhibiting both benign and aggressive behaviour. The endoscopic approach of tracheal should be considered when there is a minimal tracheal wall invasion.

CONCLUSION

Through this case, we want to emphasise the role of rigid bronchoscopy in the complete removal of endotracheal IMT.

Molecular Alterations in Pediatric Fibroblastic/Myofibroblastic Tumors: An Appraisal of a Next Generation Sequencing Assay in a Retrospective Single Centre Study

BACKGROUND

Pediatric fibroblastic/myofibroblastic tumors (PFMTs) can be challenging to definitively classify. Large case series or diagnostic updates have not been recently published despite identification of molecular alterations that could improve diagnostic accuracy. Our review of the literature found that over two-thirds of the more than 30 types of PFMTs harbor recurrent molecular alterations. We performed an institutional review of PFMTs to highlight limitations of a predominantly morphological classification, and evaluated the utility of a next-generation sequencing assay to aid diagnosis.

METHODS

PFMTs identified over a period of 12 years were reviewed, categorized per the new WHO classification, and tested using the Oncomine Childhood Cancer Research Assay.

RESULTS

Eighty-seven specimens from 58 patients were reviewed; 50 were chosen for molecular analysis, 16 (32%) lacking definitive classification. We identified alterations, some novel, in 33% of assayed cases. Expected alterations were identified for most known diagnoses and mutations were identified in 6 of 16 tumors (38%) that were initially unclassified.

CONCLUSION

We confirmed a significant subset of PFMTs remain difficult to classify using current criteria, and that a combined DNA/RNA assay can identify alterations in many of these cases, improving diagnostic certainty and suggesting a clinical utility for challenging cases.

Therapeutic options in inoperable ROS1-rearranged inflammatory myofibroblastic tumor of the tongue in a child: a case report and literature review

Inflammatory myofibroblastic tumor (IMT) is a rare borderline malignancy, usually treated with surgery only. Exceedingly rare cases of inoperable, recurrent, or metastatic IMTs pose a therapeutic challenge. We report successful treatment of a 7-year-old girl with an inoperable anaplastic lymphoma kinase (ALK)-negative IMT of the tongue. The patient underwent various anti-inflammatory (steroids, nonsteroidal anti-inflammatory drugs, clarithromycin) and antiproliferative (chemotherapy) therapies to enable tumor regression and complete resection. Ultimately, next-generation sequencing of the tumor revealed a TFG-ROS-1 translocation, allowing for an off-label targeted therapy with crizotinib. Crizotinib treatment caused slight tumor regression but evident change of its structure, allowing for complete non-mutilating resection. Two histopathology examinations revealed complete disappearance of neoplastic cells following therapy. The patient remains disease-free 22 months after the delayed surgery. In children with inoperable ALK-negative IMTs, molecular testing must be performed to identify other targetable oncogenic fusions, including TFG-ROS1.

ALK-negative lung inflammatory myofibroblastic tumor in a young adult: A case report and literature review of molecular alterations

RATIONALE

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor that is prevalent among children and adolescents. Surgery is the most important therapeutic approach for IMT and complete resection is recommended. Although 50% of IMTs show anaplastic lymphoma kinase (ALK) rearrangements, crizotinib has proven an effective therapeutic approach. However, the genetic landscape of this tumor is still not fully understood and treatment options are limited, especially in the majority of ALK-negative tumors.

PATIENT CONCERNS

We describe the clinical case of a healthy 18-year-old female in whom a pulmonary nodule was incidentally detected.

DIAGNOSES

Following a small increase in the size of the nodule, the patient underwent both 18FDG-PET/CT and 68Ga-PET/CT, resulting in a suspicion of bronchial hamartoma.

INTERVENTIONS

The patient underwent surgery and a salivary gland-like lung tumor was diagnosed.

OUTCOMES

After surgery, the patient was referred to our cancer center, where a review of the histology slides gave a final diagnosis of ALK-negative lung IMT. Given the histology, it was decided not to administer adjuvant therapy and the patient was placed in a 3-monthly follow-up program. The patient is still disease-free 2 years post-surgery.

LESSONS

Although there is no standard of care for the treatment of IMT, identifying genomic alterations could help to redefine the management of patients with negative-ALK disease. Our review of the literature on IMT and other kinase fusions revealed, in addition to ALK rearrangements, the potential association of ROS1, NTRK, RET, or PDGFR beta alterations with the tumor.

Inflammatory pseudotumor and myofibroblastic inflammatory tumor. Diagnostic criteria and prognostic differences

INTRODUCTION

Inflammatory pseudotumor (IPT) and inflammatory myofibroblastic tumor (IMT) are two very rare entities that were formerly included in the same category; however, today they are considered two different diseases due to the neoplastic origin of the IMT. Our objective is to share our experience in the management of these two types of tumors that we must take into account in the differential diagnosis of pulmonary masses or nodules.

METHODS

Thirteen patients with a pathological diagnosis of IPT and IMT who underwent surgery between 2008 and 2019 were retrospectively studied. We recorded the pre and postoperative information of each one, as well as the survival analysis.

RESULTS

Of the 13 patients, 8 were men and 5 women. The mean age of presentation was 53,5 years. An atypical segmentectomy was performed in 6 patients; a lobectomy was necessary in 6 and a pneumonectomy in 1 case. In all cases a complete resection was achieved. Diagnosis was possible thanks to histology, immunohistochemical (IHQ) and fluorescent in situ hybridization (FISH) techniques determining the expression of IgG4 and the rearrangement of ALK, respectively. After a median follow up of 49 months, we didńt find any loco-regional or distant recurrence in the patients studied.

CONCLUSION

IPT and IMT are rare tumors with a very good prognostic. The diagnosis of both entities is based mainly on specific anatomopathological techniques. Surgery has, in most cases, both a diagnostic and therapeutic role.

[Angiomatoid fibrous histiocytoma: a literature review and a report of two cases]

Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor of intermediate malignancy potential, which predominantly affects children and young adults. This paper describes two cases of AFH, as well as a review of literature during 1979 to 2021. It gives data on the epidemiology, clinical features, diagnosis, and genetic characteristics of AFH.

Rare presentation of inflammatory pseudotumour involving subcutaneous tissues with superficial fat sparing

We present a unique case of inflammatory pseudotumour involving gluteal subcutaneous tissue with the sparing of superficial fat and report its contrast-enhanced CT, F-18 fluorodeoxyglucose positron emission tomography/CT and pathological findings. Although rare, inflammatory pseudotumours have been reported with a diverse spectrum of locations; however, the involvement of the subcutaneous tissue overlying the gluteal muscles with sparing of the most superficial fat has not been reported.

Nanostring-based screening for tyrosine kinase fusions in inflammatory myofibroblastic tumors

Gene expression imbalances were measured for tyrosine kinase (TK) genes using Nanostring in 19 samples of inflammatory myofibroblastic tumor (IMT). All cases were immunohistochemically stained with anaplastic lymphoma kinase (ALK) and pan-tropomyosin-related-kinase (pan-Trk) antibodies. Five cases with imbalanced ALK expression, reported with Nanostring, were tested using fluorescence in situ hybridization (FISH); two cases with imbalanced neurotrophic tyrosine receptor kinase 3 (NTRK3) expression were tested using reverse transcription-polymerase chain reaction (RT-PCR). One case with imbalanced expression for ROS proto-oncogene 1 (ROS1) was tested using RNA sequencing and RT-PCR. TK fusions were detected in all cases with imbalanced TK expression. RNA sequencing detected a FN1-ROS1 fusion gene in an adult IMT case. IMT with ALK rearrangement showed myofibroblast-dominant features. IMT with ETV6-NTRK3 fusion showed prominent lymphoplasmacytic infiltration with scattered myofibroblasts. Pan-Trk IHC revealed only scattered positively stained cells in IMT with ETV6-NTRK3 fusion gene. ROS1-positive IMT showed myofibroblast-dominant features.

Echocardiographic Findings in Children with Native Mitral Valve Masses Complicated by Systemic Embolization

• Case of mitral valve IMT with embolization. • Case of Streptococcus pneumoniae mitral valve endocarditis with embolization. • Use of 2D and 3D echocardiography for management of mitral valve masses.

An Inflammatory Myofibroblastic Tumor of the Appendix Mimicking an Appendicular Malignant Lesion

Inflammatory myofibroblastic tumor (IMT) is a very rare lesion of unknown etiology. Cases of IMT involving the appendix are exceptional, and they can mimic malignant appendicular tumors. We present a case of a 65-year-old man who presented to our emergency room on septic shock and acute abdomen secondary to visceral perforation. The patient underwent exploratory laparotomy; massive bowel dilatation was encountered, along with 3 L of purulent intraperitoneal fluid and a perforated appendicular mass of 6 cm. An appendicectomy was performed. Histopathologic examination established the diagnosis of inflammatory pseudotumor with appendiceal perforation. This study constitutes the 14th confirmed case report of an appendicular IMT. It is important to include IMT in differential diagnoses of appendicular masses to avoid excessive resections.

ALK expressed in a gastrointestinal stromal tumor harboring PDGFRA p. D842V mutation:a case report

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common type of adult mesenchymal neoplasms. The events that drive GIST oncogenesis are primarily KIT or PDGFRA mutations, which lead to the susceptibility of these tumors to small-molecule tyrosine kinase inhibitors such as imatinib and sunitinib. However, previous studies have shown that patients with a PDGFRA D842V mutation in GISTs have a very low rate of response to imatinib treatment. Therefore, novel tyrosine kinase inhibitors (TKIs) are currently being evaluated in clinical trials to treat GISTs harboring a PDGFRA D842V mutation. Anaplastic lymphoma kinase (ALK) overexpression was not expected to be present in the GIST, and it has been used as a biomarker to distinguish GISTs from other types of mesenchymal tumors.

CASE PRESENTATION

Here, we report a 37-year-old male patient who presented with a large mass in the right upper abdomen and was subsequently diagnosed with a GIST harboring a PDGFRA D842V mutation. We unexpectedly found that the GIST in this patient exhibited simultaneous ALK expression.

CONCLUSIONS

This is the first case reported of a GIST with ALK expression. This rare phenomenon suggests that the diagnosis of a GIST cannot be excluded absolutely if a tumor exhibits ALK expression. In addition, ALK may be a potential therapeutic target for patients with imatinib-resistant stromal tumors.

ALK-TPM3 rearrangement in adult renal cell carcinoma: a case report and literature review

BACKGROUND

Translocation-associated renal cell carcinoma involving ALK (ALK-tRCC) is a rare subtype of adult renal cell carcinoma (RCC) reported in recent years. It was recognized as a group of emerging /provisional RCC in the latest World Health Organization's classification (2016).

CASE PRESENTATION

A new Chinese case of ALK-tRCC was reported. The patient was a 58-year-old man with a tumor in kidney. The tumor was composed of sheets of large cells with abundant eosinophilic cytoplasm and indistinct cell borders but conspicuous intracytoplasmic vacuoles. The nuclei were enlarged with a nucleolar of grade 4. Immunohistochemically, tumor cells were diffusely positive for PAX8, keratin (AE1/AE3), epithelial membrane antigen (EMA) and CK7. Fluorescent in situ hybridization (FISH) showed a rearrangement of ALK in tumor cells.

CONCLUSION

ALK-tRCC is a rare subtype of adult RCC. Its diagnosis is very difficult because the histological spectrum is very wide. We suggested that RCCs should be screened for ALK expression by immunohistochemistry (IHC) for the patient might benefit from ALK inhibitors therapy.

Pathology of liver disease: advances in the last 50 years

Liver disease has been recognized in various forms for centuries. Incredible advances, however, have been made especially in the last 50 years, driven by improvements in histology, the development of immunostains, the development of high resolution imaging methods, improved biopsy and resection methods, and the emergence of the molecular era. With these tools, pathologists and their clinical and basic science colleagues moved from classifying liver disease using an observational, pattern-based approach to a refined classification of disease, one based on etiology for medical disease and tumor classification for neoplastic disease. Examples of liver specific diseases are used to illustrate these exciting advances. These impressive advances of the past provide the foundation for hope in the future, as liver pathology continues to play an important role in improving patient care through disease identification and classification and emerging roles in guiding therapy for cures.

Inflammatory myofibroblastic tumor of bone harboring an ALK gene amplification

Inflammatory myofibroblastic tumor (IMT) is a neoplastic proliferation of myofibroblastic/fibroblastic cells with a variable admixture of inflammatory cells. It primarily affects soft tissue and viscera of children and young adults. IMT occurring in bone is extremely rare. Approximately 50% of IMTs carry a clonal rearrangement of the anaplastic lymphoma kinase (ALK) gene, while other receptor tyrosine kinase gene rearrangements have been seen in a small subset of IMT. Herein, we report the first case of IMT which harbors an ALK gene amplification rather than a rearrangement thus resulting in overexpression of the protein, arising from the femur of a 24-year-old man. Our case provides a novel pathogenesis for IMT. An overview of cytogenetic abnormalities of IMT is also integrated into this report.

Expanding the Molecular Characterization of Thoracic Inflammatory Myofibroblastic Tumors beyond ALK Gene Rearrangements

INTRODUCTION

Half of inflammatory myofibroblastic tumors (IMTs) regardless of anatomic location harbor anaplastic lymphoma kinase gene (ALK) rearrangements and overexpress anaplastic lymphoma kinase protein. The wide application of next-generation sequencing and the clinical benefit to tyrosine kinase inhibitors have opened new opportunities for investigation of ALK-negative IMTs.

METHODS

In this study, we have investigated a series of pediatric and adult thoracic IMTs for abnormalities in a wide spectrum of actionable kinases by applying a variety of molecular and next-generation sequencing techniques, including fluorescence in situ hybridization (FISH), targeted RNA sequencing, and NanoString assay.

RESULTS

There were 33 patients with thoracic IMTs, including five children; their mean age was 37. The tumors showed a monomorphic spindle cell phenotype, except for one with an epithelioid morphologic pattern and moderate to severe atypia. By immunohistochemistry, 24 tumors were ALK positive, and 19 of the 24 showed ALK rearrangements and one ret proto-oncogene gene (RET) rearrangement by FISH. RNA sequencing was performed in the remaining four cases lacking ALK abnormalities by FISH, revealing ALK fusions involving tropomyosin 4 gene (TMP4) and echinoderm microtubule associated protein like 4 gene (EML4) as partner in three cases. NanoString assay was performed in the remaining case, revealing ALK alternative transcription initiation (ALK^ATI). Nine cases lacking ALK abnormalities were further tested by FISH or targeted RNA sequencing, revealing ROS1 rearrangement in six cases and ETS variant 6 gene (ETV6)-neurotrophic receptor tyrosine kinase 3 gene (NTRK3) fusion in three cases, respectively.

CONCLUSIONS

By using a battery of complementary molecular techniques, we have shown that all the thoracic IMTs harbored a tyrosine kinase abnormality, with 30% involving a kinase gene other than ALK, including ROS1, NTRK3, and RET gene fusions. We have also described for the first time ALK^ATI-induced ALK oncogenic activation in IMTs.

Inflammatory Myofibroblastic Tumors in Paranasal Sinus and Nasopharynx: A Clinical Retrospective Study of 13 Cases

Background

Inflammatory myofibroblastic tumor (IMT), as a mesenchymal tumor, is common in the lung and abdomen but rare in the paranasal sinus and nasopharynx.

Objective

This study aimed to summarize the clinical characteristics of IMT in the paranasal sinus and nasopharynx and analyze the relationship between the treatment and the overall survival (OS).

Method

The clinical features, treatment, and follow-up data of patients diagnosed with IMT of the paranasal sinus or nasopharynx from 2006 to 2017 were retrospectively analyzed, and the previous literature was reviewed.

Results

IMT often presents as an ill-defined soft-tissue mass with bone destruction and invasion of surrounding structures. The treatment methods used in this study were different combinations of surgery, prednisone, radiotherapy, and chemotherapy or observation alone. Three of the 13 patients were lost and the follow-up time of the remaining 10 cases ranged from 2 to 87 months (median, 39 months). Two patients died of the disease; the other eight patients were stable. The 5-year survival rate was 72%. Among the four methods of treatment, only treatment with prednisone was significantly correlated with better OS (P = 0.046).

Conclusions

IMT is an intermediate tumor that often mimics malignancy. We are not sure if IMTs in the nasal cavity are more aggressive because of the biology or if the location and local therapy in the head region is more complicated. Radiologic findings help know the extent of the lesion. For unresectable nasal IMT, combined therapy with glucocorticoids, chemotherapy, and radiotherapy is sometimes a better choice. Glucocorticoids are especially recommended as a basic part of the integrated therapy. However, the standard treatment needs further research.

Gastric inflammatory myofibroblastic tumor treated with combined laparoscopic and endoscopic gastric wedge resection: a case report

Background

Inflammatory myofibroblastic tumor is an uncommon soft tissue neoplasm rarely reported in the stomach.

Case presentation

We identified a tumor highly suggestive of poorly differentiated gastric adenocarcinoma in the lesser curvature of the stomach of a 53-year-old female during screening endoscopy. Although the patient’s gastric biopsy did not reveal cancer, the tumor configuration was strongly suspicious for malignancy, and we performed a gastric wedge resection using a combined laparoscopic and endoscopic method. The lesion was diagnosed as inflammatory myofibroblastic tumor based on its morphological and immunohistological features.

Conclusions

Inflammatory myofibroblastic tumor should be considered in the differential diagnosis of soft tissue tumors in the stomach. We present a case of inflammatory myofibroblastic tumor safely treated with combined laparoscopic and endoscopic gastric wedge resection.

Crizotinib in ALK+ inflammatory myofibroblastic tumors-Current experience and future perspectives

Inflammatory myofibroblastic tumor (IMT) and its subtype epithelioid inflammatory myofibroblastic sarcoma (EIMS) are rare soft-tissue tumors. As about 50% of IMT and 100% of EIMS contain activating rearrangements of the anaplastic lymphoma kinase (ALK) gene, targeted kinase inhibition of ALK by compounds such as crizotinib is a potential treatment option. We performed a literature review and analyzed a total of 30 patients with IMT/EIMS treated with crizotinib. A total of 12 patients achieved complete or partial remission. As preliminary data are promising, a prospective study evaluating crizotinib treatment in patients with unresectable/multifocal ALK⁺ IMT/EIMS is warranted.

ALK-TPM3 rearrangement in adult renal cell carcinoma: Report of a new case showing loss of chromosome 3 and literature review

Seven cases of translocation-associated renal cell carcinoma involving ALK (ALK-tRCC) were referenced in the last World Health Organization's classification (2016), in a group of emerging/provisional RCC. The first three cases were pediatric, medullary-based, associated with sickle-cell trait and showed a fusion of ALK with VCL. Thirteen cases have been further described. They displayed clinical, morphological and genomic heterogeneity. Most of them occurred in adults. None of the patients was affected by sickle-cell disease. We report a new case of ALK-tRCC in a 55-year-old woman. Genomic profile showed losses of chromosomes 3, 9 and 14, anomalies often observed in clear cell RCC. VHL mutation or morphological features suggesting a clear cell RCC were not detected. We identified an unbalanced rearrangement of ALK and TPM3. Review of the literature identified similar features in our case and previously published cases: heterogeneous solid architecture, eosinophilic cells, mucinous cytoplasmic elements, rhabdoid cells and intracytoplasmic lumina. These elements may constitute the basis of a pathological definition of ALK-tRCC. Their observation in a RCC should lead to perform molecular detection of ALK rearrangement. This may have a crucial importance for metastatic patients treatment since ALK rearrangements confer sensitivity to tyrosine kinases inhibitors such as crizotinib.

A Case of Congenital Infantile Fibrosarcoma of the Bowel Presenting as a Neonatal Intussusception

Neonatal intussusception of the intestinal tract is rare. However, most neonatal intussusceptions have an organic lead point. For the lead point to be a neoplasm is extremely rare. We report a case that presented with neonatal intussusception with a congenital infantile fibrosarcoma as the lead point. The detection of ETV6-NTRK3 gene fusion was useful, although the definitive diagnosis was achieved by a comprehensive evaluation including this gene analysis, standard histology and immunohistochemistry. Neonatal intussusception should be suspected to be caused by a neoplasm. If pathological diagnosis is difficult, molecular analysis should be utilized to diagnose congenital infantile fibrosarcoma.

A case report of recurrent thyroid inflammatory myofibroblastic tumor and its metastasis in soft tissue

RATIONALE

Inflammatory myofibroblastic tumor (IMT) is a neoplasm of low malignant potential. The most frequent site of IMT is in the lung, whereas recurrent and metastasis of thyroid IMT has been seldom reported.

PATIENT CONCERNS

A 57-year-old male presented with a 3-year history of painless thyroid mass. The physical examination revealed a diffusely enlarged thyroid which was firm. The thyroid function and antibodies were normal. Thyroid ultrasound revealed a hypoechoic mass in the left lobe and heterogeneous echo in the right lobe. Neck computed tomography showed a diffused enlargement of thyroid with the homogeneously low intensity and the moderate enhancement.

DIAGNOSES

A diagnosis of thyroid IMT was made according the postoperative histological and immunohistochemical analysis.

INTERVENTIONS

The patient underwent subtotal thyroidectomy. Seventeen months after the surgery, the patients presented with a firm nodule of right adductor magnus and a relapsing mass of thyroid. Needle core biopsy of the thyroid mass suggested the relapsing of thyroid IMT. The mass excision of the right adductor magnus was performed and an IMT was confirmed by histopathology. The patient underwent thyroid radiation therapy and steroid therapy.

OUTCOMES

The size of the tumor was smaller than the preradiation size and the patient is now under follow-up.

LESSONS

This is the seldom reported patient with recurrent thyroid IMT with metastasis. IMT of the thyroid is an unusual but distinct disease entity. The clinical and radiological features are not specific and its diagnosis is based on the histological features. Although tumor resection and radiation seem to be effective, no standard treatment for such disease has been established.

PD-L1 expression and CD8+ tumor-infiltrating lymphocytes are associated with ALK rearrangement and clinicopathological features in inflammatory myofibroblastic tumors

Background

Inflammatory myofibroblastic tumors (IMTs) are rare mesenchymal neoplasms that are composed of myofibroblastic cells accompanied by inflammatory infiltrate. We investigated the immune profiles of IMTs, including PD-L1 expression and proportion of CD8+ tumor-infiltrating lymphocytes (TILs), as well as its clinicopathological characteristics according to ALK gene rearrangementstatus.

Methods

Twenty-eight IMTs from 25 patients were retrieved from our pathology files (2005–2015), and their clinicopathological parameters and outcomes were analyzed. Immunohistochemistry (IHC) was performed using whole-tissue sections to detect PD-L1 and CD8 expression, and fluorescent in situ hybridization (FISH) analysis and IHC were performed using tissue microarrays to identify rearrangements in the ALK, ROS1, and RET genes.

Results

ALK rearrangement was observed in 11 cases (44.0%), and all cases exhibited diffuse cytoplasmic ALK expression during IHC. ROS1 or RET rearrangement was not detected using IHC or FISH. IMTs harboring ALK rearrangement (ALK-positive) were located in the lungs (n = 7), genitourinary tract (n = 2), and mesentery (n = 1). The mean patient age was 33.2 years for ALK-positive IMTs and 53.1 years for ALK-negative IMTs. All patients with ALK-positive IMTs survived without recurrence or metastasis. IMTs with metastasis and/or recurrence were ALK-negative and exhibited elevated PD-L1 expression (positive tumor cells: 70.0% vs. 21.3%, P = 0.023; H-score: 107.5 vs. 26.3, P = 0.005). In addition, ALK-negative IMTs had a more CD8+ TILs, compared to ALK-positive IMTs (23.3% vs. 8.9%, P = 0.027).

Conclusion

ALK-positive IMTs are characterized by younger age, well-defined margins, frequent involvement of the lung, and fewer CD8+ TILs. Greater PD-L1 expression was observed in IMTs with tumor necrosis and metastasis/recurrence, which were also negative for ALK rearrangement. These results suggest that immune checkpoint inhibitors may be a novel option for treating patients with advanced IMT.

Inflammatory myofibroblastic tumor of the gallbladder: a case report and literature review

A 50-year-old man had undergone chemotherapy and radiotherapy for malignant lymphoma 1 year earlier. Follow-up computed tomography revealed a gallbladder polyp. Transabdominal ultrasound demonstrated a 20-mm hypoechoic sessile polyp with basal waist in the gallbladder fundus; the surface was covered with a hyperechoic layer of non-uniform thickness. On contrast-enhanced computed tomography, the polyp showed an early uniform and sustained staining pattern. Magnetic resonance imaging revealed that the polyp had low and slightly high signal intensities on T1- and T2-weighted imaging, respectively. Gallbladder bed resection was performed with the diagnosis of special tumor. Histologically, the polyp comprised a proliferation of myofibroblast-like spindle cells with inflammatory cell infiltration, without muscularis propria or vascular invasion. Most of the polyp surface was covered with necrotic exudate, and part of the normal epithelium remained. Consequently, a diagnosis of inflammatory myofibroblastic tumor was made. The sessile shape with basal waist, epithelium shedding, and surface necrotic exudative matter may represent intraluminal expansive growth such as a subepithelial tumor. A surface with a hyperechoic layer of non-uniform thickness on gallbladder polyp can help in the diagnosis of a tumor with expansive growth directly under the epithelium with stretching/rupture of the epithelium.

Sinonasal Inflammatory Myofibroblastic Tumor with Anaplastic Lymphoma Kinase 1 Rearrangement: Case Study and Literature Review

Inflammatory myofibroblastic tumors (IMTs) are rare mesenchymal tumors initially described in the lung. About half of them exhibit expression of the ALK1 protein, generally resulting from a gene rearrangement. Paranasal sinus IMTs are extremely uncommon, and gene rearrangement of ALK1 is very rare in this localization. A 47-year-old woman presented with rapidly progressive vision loss in her left eye. Clinical and imaging work-up revealed a tumor invading the left ethmoidal and sphenoidal sinuses and extending into the nasal cavity, the orbit and the skull base. Complete tumor resection was performed using an endonasal approach. Pathological examination revealed a paranasal localization of IMT, positive for ALK1 immunostaining. FISH analysis showed an ALK1 gene rearrangement. This case illustrates the local aggressive potential for IMTs. Treatment is primarily surgical, but targeted therapies (crizotinib) might be a solution for ALK1 rearranged cases with a poor prognosis.

A case of anaplastic lymphoma kinase (ALK)-positive ciliated muconodular papillary tumor (CMPT) of the lung

Ciliated muconodular papillary tumor (CMPT) is a rare papillary tumor that arises in the peripheral lung fields and is associated with the proliferation of ciliate d and goblet cells and increased mucin production. We report a case of CMPT involving the rearrangement of the anaplastic lymphoma kinase (ALK) gene. The patient was an 84-year-old Japanese female who had exhibited a small nodular shadow on chest computed tomography during a regular checkup 10 years ago. She underwent a partial resection of segment S10 of the right lung. The cut surface of the surgical specimen revealed a well-circumscribed, jelly-like mass measuring 8 × 8 × 10 mm. Histologically, the tumor was composed of a mixture of ciliated, goblet, and basal cells arranged in a papillary pattern together with pools of mucin. A diagnosis of CMPT was made. The lung tumor cells were subjected to fluorescent in situ hybridization and highly sensitive immunohistochemical staining for the ALK protein, both of which produced positive results. CMPT usually follows a favorable course, but the exact nature of this tumor; i.e., whether it is benign or malignant, has not been established. This is the first reported case of an ALK-positive CMPT.

Evolving Cancer Classification in the Era of Personalized Medicine: A Primer for Radiologists

Traditionally tumors were classified based on anatomic location but now specific genetic mutations in cancers are leading to treatment of tumors with molecular targeted therapies. This has led to a paradigm shift in the classification and treatment of cancer. Tumors treated with molecular targeted therapies often show morphological changes rather than change in size and are associated with class specific and drug specific toxicities, different from those encountered with conventional chemotherapeutic agents. It is important for the radiologists to be familiar with the new cancer classification and the various treatment strategies employed, in order to effectively communicate and participate in the multi-disciplinary care. In this paper we will focus on lung cancer as a prototype of the new molecular classification.

Clinico-radiological and Pathological Characteristics of Inflammatory Myofibroblastic Tumors in Children: A Retrospective Study

Purpose

Inflammatory myofibroblastic tumors (IMTs) are rare, benign lesions most often seen in the lung of young adults but can occur in children, in various sites. They mimic, clinically and radiologically, malignant tumors - especially sarcomas and lymphomas. The aim was to review the clinical, radiological, and pathological data of children with a diagnosis of IMT referred to our department.

Materials and Methods

This retrospective study was conducted at the Department of Medical and Paediatric Oncology, Regional Cancer Centre, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India from January 2014 to December 2015.

Results

Among 288 pediatric tumors registered during the study, 5 (1.73%) had the diagnosis of IMTs. The main symptoms were abdominal distension and pain in 60% (three cases), breathlessness and cough in 20% (one case), and right axillary area swelling in 20% (one case). In three patients, complete surgical excision was done, whereas another patient with retroperitoneal mass had the residual disease and received chemotherapy followed by complete second surgery. In the case of mediastinal IMT, surgery was followed by local radiotherapy. At present, four patients are disease-free and one patient with mediastinal IMT has the residual progressive disease.

Conclusion

On presentation, IMT can constitute a formidable challenge, from diagnosis through to treatment.

Cystic and necrotic papillary renal cell carcinoma: prognosis, morphology, immunohistochemical, and molecular-genetic profile of 10 cases

Conflicting data have been published on the prognostic significance of tumor necrosis in papillary renal cell carcinoma (PRCC). Although the presence of necrosis is generally considered an adverse prognostic feature in PRCC, we report a cohort of 10 morphologically distinct cystic and extensively necrotic PRCC with favorable biological behavior. Ten cases of type 1 PRCC with a uniform morphologic pattern were selected from the 19 500 renal tumors, of which 1311 were PRCCs in our registry. We focused on precise morphologic diagnosis supported by immunohistochemical and molecular-genetic analysis. Patients included 8 men and 2 women with an age range of 32-85 years (mean, 62.6 years). Tumor size ranged from 6 to 14 cm (mean, 9.4 cm). Follow-up data were available in 7 patients, ranging from 0.5 to 14 years (mean, 4 years). All tumors were spherical, cystic, and circumscribed by a thick fibrous capsule, filled with hemorrhagic/necrotic contents. Limited viable neoplastic tissue was present only as a thin rim in the inner surface of the cyst wall, consistent with type 1 PRCC. All cases were positive for AMACR, OSCAR, CAM 5.2, HIF-2, and vimentin. Chromosome 7 and 17 polysomy was found in 5 of 9 analyzable cases, 2 cases demonstrated chromosome 7 and 17 disomy, and 1 case showed only chromosome 17 polysomy. Loss of chromosome Y was found in 5 cases, including 1 case with disomic chromosomes 7 and 17. No VHL gene abnormalities were found. Papillary renal cell carcinoma type 1 can present as a large hemorrhagic/necrotic unicystic lesion with a thick fibroleiomyomatous capsule. Most cases showed a chromosomal numerical aberration pattern characteristic of PRCC. All tumors followed a nonaggressive clinical course. Large liquefactive necrosis should not necessarily be considered an adverse prognostic feature, particularly in a subset of type 1 PRCC with unilocular cysts filled with necrotic/hemorrhagic material.

Inflammatory Myofibroblastic Tumor in the Bladder: A Case Report

A 36-year-old male was referred to our department for further examination of asymptomatic gross hematuria emanating from a bladder tumor. Cystoscopy revealed a broad-based tumor 40 mm in diameter. Urinary cytology was negative. Preoperative magnetic resonance imaging suggested a muscle invasive tumor. Transurethral resection was performed, and the pathological findings revealed an inflammatory myofibroblastic tumor. We herein report a rare case of bladder inflammatory myofibroblastic tumor.

Inflammatory myofibroblastic tumour

While initially controversial, the proposal that a subset of inflammatory pseudotumours were myofibroblastic neoplasms is now acknowledged. Inflammatory myofibroblastic tumour is a spindle cell neoplasm of intermediate biological potential that may arise in a wide range of anatomic sites but has a particular propensity for the lung and abdominal soft tissues. Depending on its location, IMT may present with a variety of clinical symptoms and it may also express a variable pathologic phenotype, leading to a broad range of clinical and pathological differentials. Recent discoveries about the molecular signatures of IMT not only provide additional tools to assist in their diagnosis, they also point to possible therapeutic interventions that may transform the management algorithms for patients with this condition.

Subcellular Localization of Immunohistochemical Signals

In the literature, sufficient attention has not been paid to the precise subcellular localization of immunohistochemical signals, the knowledge of which is essential for proper interpretation of immunostains and distinction of genuine staining from biotin-associated or other nonspecific stainings. The subcellular localization of the signals can in fact be easily deduced from the known biologic or ultrastructural characteristics of the antigens. Extracellular antigens obviously are located in the extracellular compartment. Cellular antigens fall into 3 major groups: membranous, nuclear, and cytoplasmic. Membranous antigens include cell adhesion molecules (such as E-cadherin, N-CAM), cell surface/transmembrane receptors and proteins (such as tyrosine kinase receptors, most leukocyte antigens, CD10, CEA), and molecules linking surface molecules to cytoskeleton (such as β-catenin, dystrophin). Nuclear antigens include cell cycle-associated proteins (such as cyclins, p16, Ki-67), nuclear enzymes (such as TdT), transcription factors (such as TTF-1, CDX-2, myogenin, PAX-5), tumor suppressor gene products (such as p53, p63, WT1, Rb), steroid hormone receptors (such as ER, PR), calcium-binding proteins (such as S-100 protein, calretinin), and some viral proteins (such as CMV, herpes). Cytoplasmic antigens can take up a granular pattern due to localization in organelles, granules, or secretory vesicles (such as chromogranin, hormones, lysozyme, HMB-45), fibrillary pattern attributable to the filamentous nature of the molecules (intermediate filaments and microfilaments), or diffuse or patchy pattern due to localization in the cytosol or large vesicles (such as myoglobin, albumin, thyroglobulin). Aberrant localization of the molecules, when present, can provide important insight into disease processes and aid in their diagnosis, such as loss of membranous E-cadherin expression in lobular breast carcinoma, aberrant nuclear localization of β-catenin in colorectal adenocarcinoma, pattern of ALK staining in anaplastic large cell lymphoma correlating with the different types of chromosomal translocations, presence of additional cytoplasmic CD10 staining in the enterocytes indicative of microvillous inclusion disease, and “reversed” staining for EMA in micropapillary mammary carcinoma.

Calcifying fibrous pseudotumor of the adrenal gland: A rare case report

Calcifying fibrous pseudotumor (CFP) is a rare benign soft tissue lesion. We herein present an extremely rare case of CFP of the adrenal gland. A 32-year-old male patient presented to our hospital with a tumor-like lesion in the area of the left adrenal gland detected by ultrasound during a routine check-up several days prior. Contrast-enhanced magnetic resonance imaging examination revealed a solitary, well-circumscribed mass, in close proximity to the medial arterial branch of the left adrenal gland. Histological examination revealed that the tumor consisted of sheets of varying amount of inflammatory cell infiltration; interstitial fibrosis and psammomatous calcifications were also observed. To the best of our knowledge, this is the third case of CFP occurring in the adrenal gland in the published literature. We herein report the findings of this case and review the two previously reported cases of CFP of the adrenal gland with valuable information.

Inflammatory myofibroblastic tumor in the head of the pancreas with anorexia and vomiting in a 69-year-old man: A case report

Inflammatory myofibroblastic tumor (IMT) is a rare condition of unclear etiology that is commonly observed in the lung but rarely in the pancreas. WHO classified IMT as a potentially malignant or aggressive tumor. In the present report, the case of a 69-year-old male patient with an IMT in the head of the pancreas, who experienced anorexia, nausea and vomiting, is presented. The patient's clinical symptoms were nonspecific, and the imaging findings revealed a hypovascularized pancreatic mass with stenosis of the descending duodenum. The electronic endoscopy findings revealed protruding lesions in the duodenal bulb and the descending duodenum. Biopsies of the mass were conducted with an electronic endoscope, but were not diagnostic. Subsequent duodenopancreatectomy aided in determining a pathological diagnosis of IMT, based on the histology and immunohistochemistry results. The patient experienced a recovery without further incident, as observed during a regular follow-up 3 years later. IMT in the head of the pancreas is rare, particularly in adults. In the present study, an extremely rare case of IMT involving the head of the pancreas in an adult patient is presented, and the therapeutic options for this condition are discussed.

Omental mesenteric myxoid hamartoma, a subtype of inflammatory myofibroblastic tumor? Considerations based on the histopathological evaluation of four cases

Omental mesenteric myxoid hamartoma (OMH) is a distinctive myxoid lesion of infancy, characterized by a benign clinical behavior. In the current World Health Organization (WHO) classification of soft tissue tumors, it is considered as part of the morphologic spectrum of inflammatory myofibroblastic tumors (IMT), but this relationship with IMT is still subject to debate. Four lesions with histologic features of OMH occurring in newborns and toddlers are described and compared with classic, ALK-positive IMT. All OMH showed a peculiar dot-like immunostaining for ALK, which, in one of the cases, was cytogenetically found to be associated with an inversion of the ALK gene. While OMHs were positive for smooth muscle actin (SMA), desmin, WT1, podoplanin, and cytokeratins (CAM5.2 and AE1-3), IMT were consistently positive only for SMA (10 cases). ALK-1 displayed cytoplasmic staining in IMT and characteristic paranuclear dot-like staining in OMH.