Inflammatory myofibroblastic tumor: comparison of clinicopathologic, histologic, and immunohistochemical features including ALK expression in atypical and aggressive cases

Current management of benign retroperitoneal tumors

Benign retroperitoneal tumors (BRT) represent a rare group of heterogeneous diseases. The literature lacks high-quality evidence about the optimal management of BRT, and most of the information available takes the form of case reports or case series. The aim of this review is to provide an overview of current management strategies for adult patients with BRT. A literature search using PubMed indexed articles was conducted and BRT were classified into five different biological subgroups: 1) lipomatous tumors, 2) smooth muscle tumors, 3) peripheral nerve sheath tumors, 4) myofibroblastic tumors, and 5) others. Tumors that are primarily pelvic in origin were excluded. Despite the significant heterogeneity of the disease, several generic considerations have emerged and can be applied to the management of BRT. Specifically, the risk of misdiagnosing a BRT with another pathology such as retroperitoneal sarcoma is notable. When encountered, suspected BRT should therefore be referred to a specialized sarcoma center. Multidisciplinary tumor boards, present at these centers, have a pivotal role in managing BRT. The decision of whether to offer surgery, nonsurgical treatment or a "watch-and-wait" approach should be made after multidisciplinary discussion, depending on tumor histology. Moving forward, collaborative research efforts dedicated to BRT remain crucial in gathering evidence and knowledge to further optimize patient care.

A novel case of cutaneous myxoid spindle cell neoplasm with FMR1-ALK gene fusion and CD34/S100 co-expression

A novel class of superficial CD34+ and S100+ cutaneous spindle cell neoplasm harboring ALK rearrangements has recently been described. Morphologically, these neoplasms have been characterized by bland spindled cells organized in whorls and cords against myxoid stroma, eventuating in the designation "superficial ALK-rearranged myxoid spindle cell neoplasm." Here, we report a 78-year-old male with a 3-mm pink papule on the chest, clinically concerning for cutaneous carcinoma. Biopsy of the specimen showed a biphasic tumor with hypercellular and hypocellular zones consisting of epithelioid cells and monomorphic, bland spindled cells. The spindled cells were arranged in perineurial-like concentric whorls and cords embedded in a myxo-collagenous stroma. Neoplastic cells were diffusely positive for CD34, S100, and D5F3-ALK, without SOX10 expression. Negative markers included GLUT1, EMA, factor XIIIa, desmin, actin, and SMA. ALK-rearrangement was identified on fluorescence in situ hybridization break-apart assay. A corresponding novel FMR1-ALK fusion was found by next-generation sequencing (NGS) based RNA sequencing. Identification of this new FMR1-ALK fusion signature adds to the spectrum of diagnostic genomic alterations in this newly described class of tumors.

Inflammatory myofibroblastic tumor of the urinary bladder with FN1‑ALK gene fusion: A case report

Inflammatory myofibroblastic tumors (IMTs), which are rare tumors, exhibit myofibroblastic differentiation, often with anaplastic lymphoma kinase (ALK) gene rearrangements. A subset of IMTs identified in the urinary tract have been shown to harbor a fibronectin 1 (FN1)-ALK gene fusion. In this case report, a case of an IMT with FN1-ALK fusion in the urinary bladder was presented, and its clinicopathological characteristics were reviewed. A 45-year-old female was referred to Chungbuk National University Hospital with gross hematuria. Cystoscopy revealed a solid mass in the bladder. The patient subsequently underwent transurethral resection of the lesion. The mass comprised stellate and spindled myofibroblastic cells that were arranged in loose fascicles, with a myxoid background and a mixed inflammatory infiltrate. Immunohistochemical analysis revealed that the tumor cells were positive for vimentin, cytokeratin AE1/AE3 and ALK, and focal-positive for desmin. Targeted next-generation sequencing was subsequently employed to identify the FN1-ALK fusion. To date, the patient has undergone outpatient follow-up for 18 months, with no signs of tumor recurrence. To conclude, in total, FN1 has been identified as an ALK fusion partner almost exclusively in cases of genitourinary IMTs [13 bladder IMTs (including the present case) and two uterine IMTs]. In the present case, the FN1-ALK fusion was found to involve ALK exon 19 and FN1 exon 23. By contrast, the majority of the other IMTs with an ALK fusion have involved ALK exon 20, whereas ALK fusion involving ALK exon 18 or 19 has been reported only in genitourinary IMTs. Therefore, the FN1-ALK fusion involving ALK exon 18 or 19 may be specific to a subset of IMTs arising in the urinary bladder.

Leiomyoma-like Morphology in Metastatic Uterine Inflammatory Myofibroblastic Tumors

Uterine inflammatory myofibroblastic tumors (IMTs) are rare mesenchymal neoplasms that frequently harbor ALK gene rearrangements and have a low risk of metastasis. We reported 3 of these tumors mimicking the appearance of leiomyoma in their recurrence. These patients were 34, 43, and 45 years old. Two uterine tumors demonstrated classic morphology, with combined myxoid, compact fascicular, and hyalinized patterns and spindled cells with bipolar cytoplasmic processes, moderate atypia, and lymphoplasmacytic inflammatory infiltrates. The third had a "leiomyoma-like" appearance, with fascicles of plump spindled cells and a sparse lymphoplasmacytic infiltrate. ALK immunohistochemistry was positive in all the tumors, and all demonstrated ALK rearrangements using fluorescence in situ hybridization (n = 2) and/or RNA sequencing (n = 2). Two classic IMTs recurred at 3 and 50 months in the lung and abdomen, respectively, and recurrent tumors had a "leiomyoma-like" appearance, with 0 and 1 mitosis per 10 high-power fields, no inflammation in 1, and a sparse lymphocytic infiltrate in the other. ALK was positive in both tumors; 1 with available tissue showed an IGFBP5::ALK fusion using RNA sequencing. The third patient, who had a "leiomyoma-like" uterine tumor, experienced multiple recurrences, first in the abdomen at 100 months showing a similar appearance. Subsequent recurrence at 105 months showed transmural invasion of the sigmoid colon and a similar microscopic appearance but with the addition of infiltrative borders, moderate cellularity, mild-to-moderate atypia, and 10 mitoses per 10 high-power fields. Both recurrences were positive for ALK, and RNA sequencing revealed the same ACTG2::ALK fusion transcript identified in the primary tumor. The patient was treated with crizotinib, resulting in prolonged clinical remission, with no evidence of disease at 168 months from the initial surgery. Although "leiomyoma-like" uterine IMTs have been recently described, to our knowledge, this is the first report of recurrence of these tumors and the first report of a "leiomyoma-like" appearance in the recurrences of conventional uterine IMTs. A low threshold for performing ALK immunohistochemistry on recurrent uterine tumors can identify patients who may benefit from tyrosine kinase inhibitors.

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 tumor of the thyroid gland

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal tumor with low incidence, which is extremely rare in the thyroid. At present, there is a lack of understanding regarding the etiology, pathogenesis, diagnosis and treatment of thyroid IMT. To improve the understanding of the disease, this article reviews the pathogenesis, clinical manifestations, pathology and immunohistochemistry, diagnosis, therapy and prognosis of thyroid IMT.

A rare case report of paratesticular spindle cell tumor: Inflammatory myofibroblastic tumor

INTRODUCTION AND IMPORTANCE

Spindle cell tumors in the paratesticular region are infrequent. Accurate diagnosis requires clinical assessment, pathological analysis, and immunohistochemical (IHC) analysis.

CASE PRESENTATION

The present study reports a 33-year-old male who presented with a painless mass in his right testis. The mass grew from the size of a marble to that of a tennis ball in two years. Physical examination and ultrasonography revealed a solid mass in the right paratesticular area. The patient underwent a right paratesticular tumor excision, without interfering the right testis. Histopathologic analysis showed spindle cell tumor appearance referring to inflammatory myofibroblastic tumor (IMT).

CLINICAL DISCUSSION

IMT, also known as inflammatory pseudotumor, is a rare and benign neoplasm that can occur anywhere. Diagnosis is challenging, because it mimics other neoplasms. Immunohistochemical profiles were decisive in concluding a definitive diagnosis. Treatment, on the other hand, depends on tumor burden and connectivity to other region.

CONCLUSION

Spindle cell tumors are very rare and can be treated with simple excision if no organ adhesion is detected. Therefore, right orchidectomy was not required in our case.

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.

Sinonasal Myxoma: A Distinct Entity or a Myxoid Variant of Desmoid Fibromatosis?

Sinonasal myxoma (SNM) is a rare benign mesenchymal tumor that arises in the sinonasal cavity or maxilla and almost exclusively affects young children. Currently, it is considered a specific entity, but its molecular characteristics have not been reported. Lesions diagnosed as SNM and odontogenic myxoma/fibromyxoma (OM/OFM) were identified from the participating institutions, and the clinicopathologic features were recorded. Immunohistochemistry for β-catenin was performed on all cases with available tissue. Next-generation sequencing (NGS) was performed on all SNM cases. Five patients with SNM were identified, including 3 boys and 2 girls with an age range of 20-36 months (mean: 26 months). The tumors were well-defined, centered in the maxillary sinus, surrounded by a rim of woven bone, and composed of a moderately cellular proliferation of spindle cells oriented in intersecting fascicles in a variably myxocollagenous stroma that contained extravasated erythrocytes. Histologically, the tumors resembled myxoid desmoid fibromatosis. Three tested cases showed nuclear expression of β-catenin. In 3 tumors, NGS revealed intragenic deletions of APC exons 5-6, 9 and 15, or 16, respectively, with concurrent loss of the other wild-type copy of APC, predicted to result in biallelic inactivation. The deletions were identical to those that occur in desmoid fibromatosis, and copy-number analysis raised the possibility that they were germline. In addition, one case showed possible deletion of APC exons 12-14, and another case exhibited a CTNNB1 p.S33C mutation. Ten patients with OM/OFM were identified, including 4 women and 6 men (mean age: 42 years). Seven tumors involved the mandible, and 3 the maxilla. Histologically, the tumors differed from SNM, and all cases lacked nuclear expression of β-catenin. These findings suggest that SNM represents a myxoid variant of desmoid fibromatosis that often arises in the maxilla. Because the APC alterations might be germline, genetic testing of the affected patients should be considered.

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.

Uterine Inflammatory Myofibroblastic Tumors: Proposed Risk Stratification Model Using Integrated Clinicopathologic and Molecular Analysis

Inflammatory myofibroblastic tumor (IMT) of the uterus is a rare mesenchymal tumor with largely benign behavior; however, a small subset demonstrate aggressive behavior. While clinicopathologic features have been previously associated with aggressive behavior, these reports are based on small series, and these features are imperfect predictors of clinical behavior. IMTs are most commonly driven by ALK fusions, with additional pathogenic molecular alterations being reported only in rare examples of extrauterine IMTs. In this study, a series of 11 uterine IMTs, 5 of which demonstrated aggressive behavior, were evaluated for clinicopathologic variables and additionally subjected to capture-based next-generation sequencing with or without whole-transcriptome RNA sequencing. In the 6 IMTs without aggressive behavior, ALK fusions were the sole pathogenic alteration. In contrast, all 5 aggressive IMTs harbored pathogenic molecular alterations and numerous copy number changes in addition to ALK fusions, with the majority of the additional alterations present in the primary tumors. We combined our series with cases previously reported in the literature and performed statistical analyses to propose a novel clinicopathologic risk stratification score assigning 1 point each for: age above 45 years, size≥5 cm,≥4 mitotic figures per 10 high-power field, and infiltrative borders. No tumors with 0 points had an aggressive outcome, while 21% of tumors with 1 to 2 points and all tumors with ≥3 points had aggressive outcomes. We propose a 2-step classification model that first uses the clinicopathologic risk stratification score to identify low-risk and high-risk tumors, and recommend molecular testing to further classify intermediate-risk tumors.

Uterine inflammatory myofibroblastic tumor

Inflammatory myofibroblastic tumor (IMT) is recognized as a true neoplasm of unknown etiology, but its pathogenesis is related to abnormalities in the ALK gene. This is an uncommon tumor with a wide anatomic distribution and often constitutes a challenging diagnosis owing to its histological similarities with other tumors. Uterine IMTs are rare and their detailed characteristics should be described based on case reports and small case series. Thus, we performed a comprehensive review of the literature showing that uterine IMTs show a wide range of age at diagnosis (median, 39 years), and a symptomatology similar to that of common leiomyomas, only rarely presenting with inflammatory manifestations. IMTs represent 0.1% of "leiomyomas," an estimate that increases to 10% for pregnant women and to 14% for the smooth muscle tumors of uncertain malignant potential (STUMP) category of tumors, implying that tumors excised during pregnancy, STUMPs, and leiomyosarcomas should be systematically screened with ALK immunohistochemistry, as this is a targetable abnormality. Most reported cases are ALK-positive; the fusion partners vary, but in pregnancy-associated tumors, TIMP3 prevails. Almost 25% of the patients will show an aggressive course, and this is associated with older age, non-pregnancy-associated tumors, larger tumors, infiltrative tumor border, absence of abundant inflammation, atypia, important mitotic activity, and necrosis.

ALK-rearranged Mesenchymal Neoplasms: A Report of 9 cases Further Expanding the Clinicopathologic Spectrum of Emerging Kinase Fusion Positive Group of Tumors

Anaplastic lymphoma kinase (ALK) fusions are oncogenic drivers in diverse cancer types. Although well established in inflammatory myofibroblastic tumor (IMT) and epithelioid fibrous histiocytoma (EFH), ALK rearrangements also occur in the emerging family of kinase fusion-positive mesenchymal neoplasms. We investigated 9 ALK-rearranged mesenchymal neoplasms (exclusive of IMT and EFH) arising in 6 males and 3 females with a wide age range of 10 to 78 years old (median 42 years). Tumors involved superficial and deep soft tissue (6) and viscera (3). Three were myxoid or collagenous low-grade paucicellular tumors with haphazardly arranged spindled cells. Three were cellular tumors with spindled cells in intersecting short fascicles or solid sheets. Three cases consisted of uniform epithelioid cells arranged in nests or solid sheets, with prominent mitotic activity and necrosis. Band-like stromal hyalinization was present in 6 cases. All tumors expressed ALK; four were positive for S100 and five were positive for CD34, while all were negative for SOX10. By targeted RNA sequencing, the breakpoints involved ALK exon 20; the 5' partners included KLC1, EML4, DCTN1, PLEKHH2, TIMP3, HMBOX1, and FMR1. All but two patients presented with localized disease. One patient had distant lung metastases; another had diffuse pleural involvement. Of the six cases with treatment information, five were surgically excised [one also received neoadjuvant radiation therapy (RT)], and one received RT and an ALK inhibitor. Of the four patients with follow-up (median 5.5 months), one remained alive with stable disease and three were alive without disease. We expand the clinicopathologic spectrum of ALK-fused mesenchymal neoplasms, including a low-grade malignant peripheral nerve sheath tumor-like subset and another subset characterized by epithelioid and high-grade morphology.

A 17-Month-Old Male Infant With a Cystic Lesion of the Left Lung

CASE PRESENTATION

A 17-month-old male infant with history of an abnormal chest shadow in the left lung lower lobe was admitted to our hospital for the resection of the malformation. At 9 months of age, he was admitted to his local hospital because of a persistent cough. The chest CT scan in his local hospital indicated a cystic lesion in the left lung lower lobe associated with inflammation. However, no thoracic abnormalities were seen in antenatal ultrasonography, and no clinical symptoms were observed at birth. After anti-inflammatory treatments given to this infant, he achieved remission and was discharged from his local hospital.

Inflammatory myofibroblastic tumor of colon and duodenum: Metachronous, metastatic or local recurrence? An unusual presentation

ABSTRACT

Inflammatory myofibroblastic tumor (IMT) is a tumefactive proliferation of spindled myofibroblastic cells admixed with inflammatory infiltrate. This tumor has a predilection for the involvement of visceral soft tissues and has a tendency for local recurrence. Occurrence of metastatic or metachronous IMTs is a rare presentation. We report a rare case of a 50-year-old man with metastatic IMTs in the colon and duodenum.

Uterine Myxoid Tumor: A Case Report on a Mysterious and Unexpected Diagnosis

Inflammatory myofibroblastic tumors (IMTs) are soft-tissue tumors that are rarely malignant. They can occur throughout the body but are rarely seen in the female genital tract. To our knowledge, the literature reports only a few cases of uterine IMTs. This article describes a 60-year-old female with a uterine IMT presumed to be a fibroid. The correct diagnosis was made based on a combination of gross appearance, microscopic findings from multiple hematoxylin and eosin-stained tumor slides, and immunohistochemical staining. We also provide a literature review and compare our findings to other reported cases.

Jejunal Intussusception Secondary to a Large Inflammatory Fibroid Polyp: A Case Report and Discussion of Differential Diagnosis

Inflammatory fibroid polyp (IFP), initially considered a reactive process, is now recognized as a benign mesenchymal neoplasm of the gastrointestinal tract. We report a case of a 68-year-old woman with medically refractory Crohn disease that presented with intussusception requiring surgical intervention. The resection revealed a jejunal mass consisting of a submucosal proliferation of bland spindle cells in a fibrous stroma infiltrated by numerous eosinophils. By immunohistochemistry, the lesion was positive for vimentin and negative for desmin, smooth muscle actin (SMA), S-100, CD117, DOG1, ALK (D5F3), Melan-A, HMB-45, CD34, and STAT6. Ki-67 proliferative index was low (<1%). The mass was classified as IFP by its characteristic morphology and associated eosinophilia. IFP should be considered in the differential diagnosis of adults with intussusception or bowel obstruction. Definitive treatment typically requires surgical resection of the involved bowel segment.

Molecular testing of soft tissue tumors

BACKGROUND

The diagnosis of soft tissue tumors is challenging, especially when the evaluable material procured is limited. As a result, diagnostic ancillary testing is frequently needed. Moreover, there is a trend in soft tissue pathology toward increasing use of molecular results for tumor classification and prognostication. Hence, diagnosing newer tumor entities such as CIC-rearranged sarcoma explicitly requires molecular testing. Molecular testing can be accomplished by in situ hybridization, polymerase chain reaction, as well as next generation sequencing, and more recently such testing can even be accomplished leveraging an immunohistochemical proxy.

CONCLUSION

This review evaluates the role of different molecular tests in characterizing soft tissue tumors belonging to various cytomorphologic categories that have been sampled by small biopsy and cytologic techniques.

HIV-related bilateral inflammatory myofibroblastic tumors of the adrenal gland: a case report and literature review

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a rare disease that mostly occurs in younger people and is located in the lungs in the general population. We report a rare case of adrenal IMT in a patient with HIV infection, which is believed to be the first of its kind worldwide.

CASE PRESENTATION

We present a rare case of a 44-year-old man with HIV infection who was diagnosed with adrenal IMT. The patient refused regular highly active antiretroviral therapy 13 years ago until he was admitted to hospital after an adrenal mass was found. The patient underwent successful computed-tomography-guided needle biopsy, and pathological analysis showed fibroblastic-myofibroblastic proliferation with inflammatory infiltration, which confirmed a diagnosis of IMT. We failed to perform complete resection of the tumor because of its diffuse invasion. The patient was complicated with severe multiple pulmonary infections postoperatively because of immunodeficiency, which eventually caused his death 2 months later.

CONCLUSION

Differential diagnosis of IMT is difficult, and tumor biopsy is an essential means of diagnosis. Surgical resection is preferred for both adrenal and HIV-related IMTs. Conservative treatment should be considered when there are technical difficulties with complete resection, and most patients have achieved good outcomes. However, more cases and longer follow-up are warranted to confirm long-term outcomes of HIV-related IMT.

Uterine inflammatory myofibroblastic tumor presented as abnormal uterine bleeding: Two cases report and literature review

RATIONALE

Inflammatory myofibroblastic tumor (IMT) is an extremely rare soft tissue neoplasm consisting of the proliferation of fibroblastic-myofibroblastic cells with inflammatory infiltrates. It is known to occur in many parts of the body and can generally present with benign or locally recurrent behavior. Anaplastic lymphoma kinase is a specific diagnostic marker for IMT, and approximately 50% of IMT patients have anaplastic lymphoma kinase gene rearrangements. Reports of the female genital tract are rare.

PATIENT CONCERNS

Two patients (a 32-year-old multigravida and a 22-year-old nullipara) visited our clinic because of abnormal uterine bleeding and a uterine mass.

DIAGNOSES

Histopathological examination, immunohistochemical markers, and fluorescence in situ hybridization confirmed the presence of a rare uterine IMT.

INTERVENTIONS

The masses were completely resected via hysteroscopy. The multigravida recurred rapidly in terms of symptoms and images, whereas the nullipara was complaint-free during the follow-up period. Finally, the multigravida underwent hysterectomy and bilateral salpingectomies.

OUTCOMES AND LESSONS

Uterine IMTs can be easily overlooked because of their extremely low incidence rate and insufficient awareness among clinicians; however, uterine IMTs need to be considered in the differential diagnosis of uterine masses. Possible differences in the biological behavior of IMT may exist in different individuals.

Laparoscopic treatment of inflammatory myofibroblastic tumor in liver: A case report

BACKGROUND

Inflammatory myofibroblastic tumor in the liver (IMTL) is a rare borderline mesenchymal tumor. Neither clinical symptoms nor laboratory tests have absolute specificity for the diagnosis of IMTL, and imaging also lacks obvious specificity. Although there are sporadic reports of recurrence after surgical treatment, surgical resection is the mainstay of treatment.

CASE SUMMARY

A 29-year-old man complained of general weakness, slight discomfort in the upper abdomen, with a history of upper respiratory tract infection for 1 wk before admission. Plain and enhanced upper abdominal magnetic resonance imaging showed a mass in liver segments II and III (48 mm × 53 mm). He was treated by laparoscopic left lateral segmentectomy. Postoperative pathological examination with hematoxylin and eosin staining suggested that the mass in liver segments II and III was IMTL. During 21 mo postoperative follow-up, no obvious residual or recurrent lesions were observed.

CONCLUSION

There is a risk of malignant degeneration in IMTL. The principal choice of treatment is laparoscopic left lateral segmentectomy.

Superficial CD34 Positive Fibroblastic Tumour with Myxoid Stroma

Superficial CD34 positive fibroblastic tumor is a rare low-grade neoplasm of the skin and subcutis with indolent behavior. This entity has been included in the current World Health Organisation (WHO) classification of soft tissue tumors. Pathological diagnosis can be challenging due to significant morphological overlap with other entities and the large spectrum of CD34 positive tumors. We report a case in a twenty-five male which showed characteristic diagnostic features, but in addition showed myxoid stroma. The presence of myxoid stroma has not been previously emphasized in this entity and broadens the histologic differential diagnosis significantly to include myxoid soft tissue tumors. A subset of these tumors harbor PRDM10-rearrangements, but a defining molecular feature has not yet been described, highlighting the need for further molecular characterization of this potentially genetically heterogenous tumor. Awareness of this entity among surgeons and pathologists is important to prevent misclassification as an aggressive sarcoma and avoid over-treatment.

Plasma Cell Granuloma of the Maxillary Sinus-A Case Report and Review

Plasma cell granuloma is a rare, benign, space occupying lesions occurring after recurrent infections. It most commonly involves young adults with lungs being the most common site. They are usually rounded masses with bony expansion and destruction without any life threatening complications and surgery being the best choice of treatment. Here we reported a 33 year-old female with plasma cell granuloma of the maxillary sinus treated with surgery and no recurrence has been noted.

Transanal total mesorectal excision for treating a lower rectal inflammatory myofibroblastic tumor: A case report

Rectal inflammatory myofibroblastic tumors are extremely rare, with no reports of their preoperative diagnosis. A 17-year-old woman who presented with low-grade fever, repeated diarrhea, constipation, and a 1-month history of anal pain was referred to our hospital. Rectal examination revealed a palpable hard mass with a smooth surface at the posterior wall 4 cm from the anal verge. Colonoscopy revealed a 4.0-cm submucosal tumor in the upper edge of the anal canal. Computed tomography and magnetic resonance imaging revealed a 5.0 × 4.0 cm-sized well-defined tumor contacting the rectum. Computed tomography-guided biopsy was performed, and an inflammatory myofibroblastic tumor was diagnosed. There have been no reports of surgery for a rectal inflammatory myofibroblastic tumor using transanal total mesorectal excision. We preoperatively diagnosed the patient with an inflammatory myofibroblastic tumor in the lower rectum and achieved anorectal preservation and curative resection with transanal total mesorectal excision, providing good view of the deep pelvis.

Inflammatory Myofibroblastic Tumour of the Sinonasal Tract with Orbital and Intracranial Extensions Simulating a Malignancy: A Case Report and Review of Literature

Inflammatory Myofibroblastic Tumour (IMT) is a rare pathology of unknown etiology. It is pathologically benign, but clinically locally invasive. We are herewith reporting a unique case of rapidly growing sinonasal IMT with orbital and intracranial extensions in a middle aged female patient masquerading as a malignancy. The lesion was excised endoscopically with margins and the patient is presently under close follow up. The report also reviews the common sites of involvement and management options available, based on a literature review.

Inflammatory Myofibroblastic Tumor of the Hilar Bile Duct: A Case Report and Literature Review

Background

Inflammatory myofibroblastic tumor (IMT) is a very rare tumor and occurs seldom in the biliary tract. IMT can occur in any part of the body and in people of any age; however, it most commonly occurs in children or adolescents. Its etiology and pathogenesis are currently unknown. The clinical manifestations of a hilar inflammatory myofibroblastic tumor are atypical, and the imaging examination is nonspecific. The diagnosis is mainly based on histopathology and immunohistochemistry findings, and surgical resection is the preferred treatment method.

Case Description

Herein, we report a rare case of hilar bile duct IMT and review the related literature. Our patient was a 54-year-old woman presenting with a 1-day history of upper abdominal pain as the main clinical symptom. She was misdiagnosed as having cholangiocarcinoma before the surgery. She underwent surgery and was ultimately diagnosed with IMT based on histopathology and immunohistochemistry findings. On 1-year follow-up, no tumor recurrence or related complications were noted.

Conclusions

We hope this case report helps clinicians gain a deeper understanding of biliary IMT of the hilum.

Malignant inflammatory myofibroblastic tumor: a rare case presentation

Malignant inflammatory myofibroblastic tumors (IMT) are extremely rare, aggressive tumors with variable presentation. This is a case of a 29-year-old female presented with severe anemia and a large abdominal mass presumed to be a gastrointestinal stromal tumor (GIST). Severe anemia, leukocytosis and thrombocytosis accompanied the presentation. Final pathological assessment yielded a diagnosis of malignant IMT. Given the rarity of these tumors, no established diagnostic criteria exist aside from histological analysis of the tissue, which may result in delays or inappropriate treatment. As these tumors are aggressive in nature, a high index of suspicion is critical to improve outcomes. Further reports on the presentation, diagnosis and treatment of such rare tumors are important to develop clinical diagnostic guidelines to improve diagnosis and treatment and improve outcomes.

Inflammatory Myofibroblastic Tumor Mimicking a Cavitary Lesion in the Lung: A Case Report and a Comprehensive Literature Review

Inflammatory myofibroblastic tumors (IMTs) are a group of soft tissue neoplasms with a predilection for the lungs and abdominopelvic cavity, characterized by a mixture of fasciitis-like, compact spindle cells, hypocellular fibrous histologic patterns, and distinctive molecular features. Due to their unspecified symptoms and non-specific radiologic presentation, the histopathologic and immunohistochemical analysis of a biopsy specimen is crucial for the diagnosis. We present a case of a 30-year-old man with intermittent hemoptysis diagnosed with a pulmonary IMT. We aim to review the literature regarding its definition, clinical findings, diagnosis, treatment, and prognosis. The treatment for an IMT is based on its location and extent, including complete surgical resection, which has a good prognosis compared to corticosteroids, chemotherapy, radiotherapy, and non-steroidal immunomodulation in patients who are not good surgical candidates. Further investigative studies with larger sample sizes and longer meticulous follow-ups are needed to demonstrate this neoplastic disease's natural history and find appropriate management for it.

Incidences and characteristics of primary lung malignancies in childhood in Germany: An analysis of population-based data from German cancer registries

BACKGROUND

Primary lung malignancies are a heterogeneous group of cancers that occur very rarely in childhood. Due to limited knowledge of their epidemiologic and clinical features, these tumors present a challenge to the treating physicians. This study aimed to increase the knowledge about the occurrence of primary lung malignancies in childhood in Germany.

MATERIALS AND METHODS

Pseudonymized data of cases recorded at the German Center for Cancer Registry Data (ZfKD) between 1990 and 2017 were retrieved. Primary lung malignancies were identified using the ICD- and ICD-O classification. Numbers were compared to those reported to the German Childhood Cancer Registry (GCCR). Crude incidence rates were calculated using the ZfKD database.

RESULTS

A total of 168 patients diagnosed with primary lung malignancies in the age below 19 years were identified from the ZfKD. The median age at diagnosis was 13 years. The most common tumor entities were lung carcinoids (n = 49), lung carcinoma (n = 36), and pleuropulmonary blastoma (n = 14). An unexpected accumulation of lung cancer cases was noted in the first year of life without a clearly specified histopathological diagnosis. A substantial discrepancy in the numbers of primary lung malignancies between ZfKD and GCCR was found.

CONCLUSIONS

We present population-based data on the occurrence of primary childhood lung malignancies in Germany, which were more frequent than previously anticipated but likely remained underreported. For better understanding and optimal treatment of these entities, cancer registration needs to be improved through mandatory reporting to the GCCR and regular data sharing between GCCR, population-based and clinical cancer registries.

Treatment, pathological characteristics, and prognosis of pulmonary inflammatory myofibroblastic tumor–a retrospective study of 8 cases

Objective

Inflammatory myofibroblastic tumor (IMT) is a rare disease. We reviewed data from eight patients diagnosed with pulmonary IMT (PIMT) at our hospital with the aim of summarizing and analyzing the characteristics of PIMT to improve our understanding of the disease.

Methods

From January 2012 to December 2019, eight patients underwent surgical intervention for PIMT at The First Affiliated Hospital of Bengbu Medical College. Resected tumors were subjected to pathological and immunohistochemical analyses. The follow-up duration for all patients ranged from 2 years and 3 months to 9 years and 9 months (median: 6 years and 9 months).

Results

The male:female ratio was 5:3, and the mean age was 48.50 years (21–74 years). Two patients (25%) with lung disease discovered via chest computed tomography during physical examinations had not experienced any symptoms. Six patients (75%) presented at the hospital because of cough, expectoration, blood in sputum, and chest tightness. Lesions from all eight patients were surgically removed, and PIMT was confirmed based on pathological examinations and immunohistochemical results. No patient received additional treatment after discharge. All cases have been followed up to the time of writing, without any tumor recurrence or distant metastasis.

Conclusion

The age of onset of PIMT is usually over 40 years, and its clinical symptoms are easily confused with those of lung cancer. PIMT can only be diagnosed by histopathology and immunohistochemistry. Complete surgical resection is the preferred treatment, as patients undergoing surgery require no additional treatment, such as chemotherapy, and the survival rate is good.

Infant biliary cirrhosis secondary to a biliary inflammatory myofibroblastic tumor: A case report and review of literature

BACKGROUND

A biliary inflammatory myofibroblastic tumor (IMT) is a rare type of mesenchymoma that, although it has a broad age spectrum, usually occurs in adults. Diagnosis is difficult because biliary IMTs often exhibit nonspecific clinical symptoms and imaging features, resulting in delayed or inappropriate treatment. Although most IMTs are benign, some show malignant properties such as infiltration, recurrence, and metastasis.

CASE SUMMARY

Here, we retrospectively describe a 10-month-old infant who was admitted to our hospital due to stubborn jaundice. The patient responded poorly to routine medical treatment and his clinical manifestations and laboratory tests lacked specificity, so we turned to repeated ultrasound scans and other imaging examinations. As both hepatosplenic ultrasonography and diffusion-weighted magnetic resonance imaging demonstrated a space-occupying lesion, an exploratory laparotomy was performed. The final diagnosis made over two mo after the disease onset was infant biliary cirrhosis caused by a biliary IMT, which partially infiltrated into the liver. This infant is the youngest case of biliary IMTs that has been reported till now. The patient underwent an incomplete resection of the mass and Kasai Portoenterostomy. However, because of cirrhosis, he also received a paternal liver transplant. Since some IMTs show malignant properties, we proceeded with a three-year of follow-up; however, no recurrence or metastasis has been noted.

CONCLUSION

Neoplastic disease such as IMTs should be considered when routine medical treatment of obstructive jaundice is not successful. Observation of dynamic imaging changes is helpful for diagnosis. Periodic follow-up is necessary for IMTs.

Clinicopathological Features of Inflammatory Myofibroblastic Tumor in the Breast

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal spindle cell tumour with low malignant potential which is extremely rare in breasts. Because of the lack of typical imaging and clinical characteristics of IMT, it is easy to misdiagnose before operation. We now report a case of a 37-year-old woman presenting with a mass in her left breast. Ultrasound showed a well-circumscribed lesion in the lower outer quadrant. The patient underwent lumpectomy, and histopathology revealed a tumor which was composed of fusiform cells and inflammatory cells. Immunohistochemistry (IHC) showed tumor cells are positive for vimentin, ALK, BCL2, and SMA. The FISH test demonstrated ALK (2p23) chromosomal translocation (ALK positive). The final diagnosis of breast IMT was rendered with nonclassical morphology. Postoperative 30-month follow-up no evidence showed residual tumor or recurrence. As a very rare tumor, breast IMT could be easily misdiagnosed clinically and pathologically. Complete surgical resection of the tumor is preferred, and it has the risk of recurrence and metastasis.

TIMP3::ALK fusions characterize a distinctive myxoid fibroblastic tumor of the vocal cords: a report of 7 cases

We report 7 cases of an indolent, variably myxoid tumor of the vocal cords, characterized by overt cellular atypia with large cells containing intranuclear and intracytoplasmic vacuoles, delicate curvilinear vessels, and sparse inflammatory infiltrate. Six patients were male, aged 15 to 65 years, and 1 patient was a 54-year-old female. All tumors were located in the superficial portion of the vocal cord. One patient suffered a recurrence that was completely resected; all patients with available follow-up data currently have no evidence of disease. The tumors contained alternating areas with myxoid stroma and more compacted regions with tumor cells organized in short fascicles, interwoven with delicate curvilinear vasculature. Overt cellular atypia with large cells containing intranuclear and intracytoplasmic vacuoles or resembling ganglion cells was present in all cases but mitoses and necrosis were absent. ALK immunostaining was positive in all cases, while most tumors were negative for smooth muscle actin. Targeted RNA-sequencing revealed an identical TIMP3::ALK fusion with exon 1 of TIMP3 gene being fused with exon 12 of ALK gene in all analyzable cases. For various reasons discussed, it remains unclear whether this tumor represents a mere subtype of IMT or a separate entity. Nevertheless, it is a morphologically distinct and diagnostically challenging lesion that needs to be recognized by surgical pathologists in order to prevent overdiagnosis in this clinically very delicate area.

Mesenchymal neoplasms of the urinary bladder: a comprehensive review with focus on cross-sectional imaging findings

Mesenchymal neoplasms of the urinary bladder are exceedingly rare and display remarkable diversity. These tumors demonstrate distinct pathological features as well as variable biological behavior and cross-sectional imaging findings. The rarity of tumors, nonspecific symptoms and seemingly normal cystoscopic findings (particularly with small and exophytic tumors) frequently lead to misdiagnosis or missed diagnosis. While some tumors display characteristic cross-sectional imaging findings that may suggest a diagnosis, imaging findings are mostly nonspecific. Histopathological examination is required for accurate diagnosis, management and prognostication. The purpose of this article is to review the cross-sectional imaging findings of a diverse spectrum of mesenchymal tumors of the urinary bladder.

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.

Locally Advanced Inflammatory Myofibroblastic Tumor Treated With Targeted Therapy: A Case Report and Literature Review

Inflammatory myofibroblastic tumors (IMTs) are known to be associated with anaplastic lymphoma kinase (ALK) gene rearrangements. Other molecular alterations such as ROS proto-oncogene 1, receptor tyrosine kinase (ROS1), neurotrophic tyrosine receptor kinase (NTRK), and platelet-derived growth factor receptor (PDGFR) have also been identified in IMTs. Although there are no randomized controlled clinical trials comparing chemotherapy, tyrosine kinase inhibitors (TKIs), or other systemic therapies, the literature demonstrates the use of ALK-targeted TKIs as an effective strategy for the treatment of locally advanced or metastatic ALK-rearranged IMTs. This case report describes a patient with an ALK-rearranged locally advanced pulmonary IMT who was treated with neoadjuvant-intent crizotinib. The patient had a very favorable response to therapy, and surgery was declined. It is difficult to determine the duration and sequencing of TKI use in these settings as there is little published data to guide decisions. This report also includes a comprehensive compilation of published IMT cases with molecular alterations treated with systemic therapy, which also highlighted the duration of therapies and clinical outcomes.

[Histological, immunohistochemical and molecular study of a paratesticular dedifferentiated liposarcoma with inflammatory myofibroblastic tumor-like features]

We report the histological, immunohistochemical, and molecular findings of a dedifferentiated liposarcoma with inflammatory myofibroblastic tumor-like features occurring in the paratesticular region. Histologically, the dedifferentiated component closely resembled an inflammatory myofibroblastic tumor. The neoplastic cells were positive for smooth muscle actin with focal CD56, CD99, Bcl2 and EMA expression. WT1, calretinin, myogenin, CK(AE1/AE3), desmin, H-caldesmon, CD34, ALK, CKIT, DOG1, MUC4 and STAT6 were negative. MDM2 showed diffuse and strong nuclear positivity in neoplastic cells and fluorescence in situ hybridization (FISH) revealed amplified MDM2 (high level) but no SYT rearrangement. Although a lipomatous component was evident macroscopically, well-differentiated liposarcomatous components were not evident in the section examined. Dedifferentiated liposarcoma can have prominent inflammatory myofibroblastic tumor-like features. Pathologists should be aware of this histological variant in order to avoid misdiagnosing dedifferentiated liposarcoma as inflammatory myofibroblastic tumor or other spindle cell tumors which have different behavioral patterns and treatment requirements.

Endotracheal inflammatory myofibroblastic tumour: A rare cause of central airway occlusion in adults

Inflammatory myofibroblastic tumour (IMT) is an unusual myofibroblastic spindle cell neoplasm that is rarely discovered in the airway of adults. Previously, it was regarded as a reactive lesion and was infamously known as inflammatory pseudotumour before recent insights revealed that significant majority of cases harboured neoplastic genes. Diagnosis is difficult as clinical presentation and imaging findings are non‐specific. Diagnosis and a favourable prognosis require the complete resection of the tumour. Detection of the anaplastic lymphoma kinase expression via immunohistochemistry expedites diagnosis. We report a young adult with an endotracheal mass occluding the central airway. The patient successfully underwent bronchoscopic resection using interventional techniques. IMT was diagnosed. No recurrence was seen after a year of surveillance. Due to the rarity of the disease, the recurrence rates for large airway disease is unknown. Recurrence rates for pulmonary lesions is reported to be lower compared to extrapulmonary IMTs and recurrence is unlikely if compete surgical excision is achieved.

Pulmonary inflammatory myofibroblastic tumor in a male child: A case report

Pulmonary inflammatory myofibroblastic tumor (IMT) is a rare condition in the normal population and specifically in the pediatric population. We reported a 9‐year‐old male child who presented with cough and intermittent fever and weight loss that was most suggestive of the infectious process. We reviewed the consideration of diagnosis and treatment.

Pulmonary IMT is a rare pulmonary mass that might be asymptomatic or manifest by hemoptysis, cough, constitutional symptoms, and pneumonia. It should be in the mind that IMT might mimic neoplasms, by history, radiology, and clinical aspects.

Mesenchymal tumors of the stomach: radiologic and pathologic correlation

Mesenchymal tumors of the stomach are uncommon, with gastrointestinal stromal tumor (GIST) being the most common among them. Majority of the tumors may arise from cells of Cajal, smooth muscle cells, neural cells, totipotent stem cells, adipocytes or fibroblasts. Imaging plays an important role not only in staging but also in characterizing these tumors. Many of these tumors have characteristic imaging features. GISTs usually present as large cavitating and necrotic tumors with exophytic component. Presence of fat tissue within the tumor suggests a lipoma or a teratoma, early phase hyperenhancement indicates glomus tumor and hemangioma, and delayed contrast enhancement is seen in schwannoma. Their differentiation from epithelial tumors like carcinoma and neuroendocrine tumors is often possible based on the location (mesenchymal tumors are intramural), spread, morphological appearance and enhancement patterns. However, overlapping features exist between these tumors with imaging often being only suggestive. A biopsy is necessary for a definitive diagnosis in many cases.

Cutaneous Inflammatory Myofibroblastic Tumor with CARS-ALK Fusion: Case Report and Literature Review

Cutaneous inflammatory myofibroblastic tumors (IMT) constitute a rare entity, generating a diagnostic pitfall when diagnosing spindle cell proliferation within the dermis. Raising awareness of this tumor among dermatopathologists remains vital in differentiating it from common cutaneous tumors such as fibrous histiocytoma, atypical fibroxanthoma, melanoma, poorly differentiated carcinoma, and other more aggressive tumors. Accurate diagnosis of IMT aid in ensuring appropriate management and follow-up for patients while preventing unnecessary harm and overtreatment. Here we report a case of a 38-year-old female with a painless, slow-growing nodule of the left posterior scalp initially diagnosed as a dermatofibroma. The histological examination revealed an ill-defined dermal nodule of spindled cells without connection or infiltration of the epidermis. At high power, the cells were arranged in fascicles with a prominent background of lymphocytic infiltrate. Immunohistochemical analysis showed strong diffuse immunoreactivity for anaplastic lymphoma kinase (ALK), targeted RNA sequencing identified a CARS-ALK fusion ultimately confirming the accurate diagnosis of a cutaneous IMT. This article is protected by copyright. All rights reserved.

Intraocular myofibroblastoma tumour of the ciliary body: a case report and literature review

Background

Inflammatory Myofibroblastoma Tumors (IMTs) are extremely tumour rare in the intraocular.

Case presentation

A ciliary body tumor was found under slit lamp biomicroscopy in a 55-year-old male first diagnosed with cataract. Then this patient underwent trans-sclera resection via partial lamellar sclerouvectomy and par plans vitrectomy to remove the mass. Hematoxylin and eosin (HE) staining and immunohistochemistry findings showed that the characteristics of the tumor were consistent with IMT.

Conclusions

We reported a rare case of intraocular IMT, which is confirmed by H&E staining, and IHC positive staining for Vimentin, Desmin and ALK, while negative staining for SMA, S-100, ki-67, CK, CD68, and calponin.

Clinical, pathologic, and molecular features of inflammatory myofibroblastic tumors in children and adolescents

BACKGROUND

Inflammatory myofibroblastic tumors (IMT) are rare, intermediate malignant tumors harboring frequent somatic molecular rearrangements. The management of IMT has not been standardized.

METHODS

A retrospective multicenter study was conducted on all pediatric patients treated for IMT between 2000 and 2019.

RESULTS

This series included 39 cases of IMT, with a median age at diagnosis of 7 years (range 20 days to 16 years). Tumor location included pelvis-abdomen (n = 16), thorax (n = 14), head and neck (n = 7), and limbs (n = 2). One patient had metastatic disease. Immunochemistry showed 21/39 (54%) anaplastic lymphoma kinase (ALK)-positive tumors. Somatic tyrosine kinase rearrangement was present in 31/36 (86%) of the tumors analyzed: 21 ALK, five ROS1, and five NTRK. Immediate surgery was performed in 24 patients (62%), with adjuvant therapy for three patients. Delayed surgery after neoadjuvant therapy was possible in 10 cases. Exclusive systemic therapy was delivered to four patients; one patient with orbital IMT was managed by watchful waiting. After a median follow-up of 33 months (range 5-124), eight (20%) recurrences/progressions occurred after surgery (seven after primary surgery and one after delayed surgery), after a median interval of 7 months (range 2-21), all in thoracic locations. The 3-year overall and disease-free survivals were 96.8% (95% CI: 79.2%-94.0%) and 77.4% (95% CI: 59.6%-88.1%), respectively. Relapses/progressions were more common in patients with a thoracic primary (p < .001) or after incomplete surgery with no adjuvant therapy (p = .027).

CONCLUSION

Surgery is effective in most cases of pediatric IMT. Systematic analysis of tyrosine kinase rearrangement is recommended. When the tumor is deemed only partially resectable to preserve organs and function, neoadjuvant therapy may be proposed to allow adequate conservative surgery.

Inflammatory Myofibroblastic Tumor in the Thyroid Gland: A Retrospective Case Series Study and Literature Review

Background: The objective of this study was to investigate the clinical characteristics, diagnosis and treatment of inflammatory myofibroblastoma tumor (IMT) in the thyroid gland. Methods: A total of 17 patients with IMT by pathology from 2010 to 2020 were included in this study. Clinical features, imaging features, treatment and prognosis were analyzed in this retrospective study. Results: The case series comprised 5 males and 12 females, with an average age of 49.6±15.36 years. The patients were divided into two cohorts: with IMT without further pathological changes and with further pathological changes of the thyroid gland (for example nodular goiter or autoimmune thyroid disease). No significant differences were detected in tumor size and extrathyroid extension between the two groups. Fine needle aspiration biopsy examination before the operation was performed in 2 cases, and rapid freezing pathology examination during the operation was performed in 7 cases. Ultrasound images of 5 cases with only one type of pathology, IMT presented a high and intermediate risk of malignancy. In the other 11 cases with further pathological changes of the thyroid gland, the image could be very low risk of malignancy or benign feature. Only 2 cases showed a high risk of malignancy ultrasound features. 5/17 patients underwent preventive cervical lymph node dissection additional to thyroid surgery. None of the lymph nodes were confirmed positive by postoperative pathology. Thyroid ultrasound, computed tomography scan of the lungs, abdomen ultrasound and thyroid function tests were routine follow-up tests. During the follow-up period of 26-141 months, 2 cases were lost, and remaining 15 cases had no recurrence or metastasis and were considered cured. Conclusion: IMT in the thyroid gland is a rare disease with a good prognosis and surgical resection is the preferred treatment.

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.

Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 1: tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors

There are numerous soft tissue tumors and tumor-like conditions in the pediatric population. Magnetic resonance imaging is the most useful modality for imaging these lesions. Although certain soft tissue lesions exhibit magnetic resonance features characteristic of a specific diagnosis, most lesions are indeterminate, and a biopsy is necessary for diagnosis. We provide a detailed update of soft tissue tumors and tumor-like conditions that occur in the pediatric population, emphasizing each lesion's conventional magnetic resonance imaging appearance, using the recently released 5th edition of the World Health Organization Classification of Soft Tissue and Bone Tumors as a guide. In part one of this review, pediatric tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors are discussed. In part two, vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas are reviewed. Per the convention of the WHO, these lesions involve the connective, subcutaneous, and other non-parenchymatous-organ soft tissues, as well as the peripheral and autonomic nervous system.

What do we know about inflammatory myofibroblastic tumors? - A systematic review

BACKGROUND

Inflammatory myofibroblastic tumors (IMTs) are rare intermediate-grade neoplasms that have a high recurrence rate after excision and exhibit low metastatic potential. These tumors contain proliferating neoplastic, fibroblastic and myofibroblastic cells, and are also characterized by chronic inflammatory infiltration by lymphocytes, plasma cells, eosinophils, and histiocytes. They belong to the group of inflammatory spindle cell lesions. Some reactive lesions, such as inflammatory pseudotumors, may appear to be IMTs, which makes their differential diagnosis extremely difficult. The aim of this article is to compile the recent information on IMTs to aid in their diagnosis and treatment.

METHODS

We reviewed articles published between 2017 and 2021, which were selected from online medical databases. In addition, some earlier articles and latest scientific monographies were analyzed.

RESULTS

The terminology used for inflammatory spindle cell lesions seems to be confusing. The terms "inflammatory myofibroblastic tumors" and "inflammatory pseudotumors" are interchangeably used by many scientists. However, a detailed analysis of the development of terminology suggests that the term "inflammatory myofibroblastic tumors" should be used to refer to a neoplastic lesion.

CONCLUSIONS

IMTs are rare neoplasms, which have not been investigated in detail due to the difficulty in collecting a large number of cases. Thus, our knowledge about this disease remains unsatisfactory. Recently developed techniques such as next-generation sequencing and computer-aided histopathological diagnosis may be useful in understanding the etiopathology of IMTs, which will help in the selection of the most appropriate therapy for patients.