Intra-abdominal inflammatory myofibroblastic tumor: Spontaneous regression

Spontaneous Regression of a Pulmonary Inflammatory Myofibroblastic Tumor

Inflammatory myofibroblastic tumors are rare benign mesenchymal neoplasms composed of myofibroblastic cells intermixed with an inflammatory infiltrate of cells including plasma cells, lymphocytes, and histiocytes. These tumors are commonly seen in children and are rare in adults. Management of these tumors is challenging due to their unpredictable behavior. Here, we present a rare case of a pulmonary inflammatory myofibroblastic tumor that regressed spontaneously following a minimally invasive computed tomography-guided percutaneous lung biopsy.

Thoracic epithelioid inflammatory myofibroblastic sarcoma: a rare and aggressive disease with case report and literature review

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is a rare subtype of inflammatory myofibroblastic tumor, characterized to be an aggressive disease with high frequency of ALK rearrangement, rapid recurrence, and poor prognosis. Primary EIMS of thoracic origin is rarely observed. Herein, we described a case of 28-year-old female developed primary EIMS in the anterior mediastinum with hepatic metastasis. The EIMS displayed sheet-like growth of epithelioid and spindle cells with enlarged nuclei, abundant and eosinophilic cytoplasm, and infiltration of inflammatory cells. Immunohistochemical staining revealed positive expression of ALK in the nuclear membrane, and ALK rearrangement was identified by polymerase chain reaction assay. Alectinib showed partial response, and achieved a meaningful survival benefit for four months. Based on this case report and literature review, ALK inhibitor reveals promising activity on the rare but aggressive EIMS. Awareness of EIMS in thoracic disease and its clinicopathological features is essential to avoid erroneous diagnosis.

Gastric inflammatory myofibroblastic tumor presented with severe anemia and inflammation: a case report

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a rare stromal tumor, often found in children and young adults, and most commonly occurs in the lungs. Surgical resection is considered the standard treatment for localized IMT, although only limited data exist. Gastric IMT in adults is extremely rare, and there are no established guidelines for its treatment.

CASE PRESENTATION

A 69-year-old male presented with persistent fatigue and weakness. Laboratory examination revealed severe anemia and inflammation. Upper gastrointestinal endoscopy at admission revealed a 40-mm type I softish tumor in the lesser curvature of the gastric body, without apparent hemorrhage. Repeated biopsies, including partial resection with snare, failed to give a definitive diagnosis. Computed tomography (CT) revealed a massive lesion at the gastric body, protruding into the gastric lumen, which was consistent with the gastric tumor. After admission, the patient developed anemia refractory to frequent blood transfusions despite the absence of apparent gastrointestinal bleeding. In addition, the patient had recurrent fevers of 38 °C or higher, and persistent high inflammatory levels. Fluorodeoxyglucose-positron emission tomography (FDG-PET) CT 1 month after the first visit exhibited an increased FDG uptake in the gastric tumor. In addition, this CT scan revealed a rapid increase in tumor size to 75 mm. It was suspected that the undiagnosed gastric tumor caused these serious clinical symptoms, and he underwent distal gastrectomy and cholecystectomy. The gross image of the tumor showed an 80-mm cauliflower-like shape with a gelatinous texture. The histopathological diagnosis was IMT. The postoperative course was uneventful, and the patient's symptoms subsided drastically, improving both anemia and systemic inflammation. The patient has shown no recurrence or relapse of the symptoms over one and a half years.

CONCLUSIONS

In this case, the tumor resection finally enabled the diagnosis of IMT and resolved the clinical symptoms. Despite its predominantly benign morphological nature, some cases of IMT present clinically adverse courses. Surgical treatment may lead to its final diagnosis and improvement of clinical symptoms.

Epithelioid Inflammatory Myofibroblastic Sarcoma With Poor Response to Crizotinib: A Case Report

Introduction

Epithelioid type inflammatory myofibroblastic sarcoma (EIMS) is a subtype of inflammatory myofibroblastic tumor (IMT). It consists of round or epithelioid cells, and almost all types of EIMS contain rearrangements of the anaplastic lymphoma kinase (ALK) gene.

Case presentation

We describe a 20-year-old female presenting with abdominal pain and a rapidly growing intraabdominal mass who underwent surgical tumor resection. She was diagnosed with EIMS. ALK and ki-67 expressions were detected in immunohistochemistry assessment. She was started with Crizotinib 200 mg twice a day, and chemotherapy was also initiated due to the recurrence of the disease 4 months after the initial treatment. She was unresponsive to all the medical regimens and died in 8 months.

Conclusion

Approach to patients with EIMS is really challenging in terms of both diagnosis and treatment. Patients with combined surgical and non-surgical treatment regimen were seen to have a more favorable outcome in some EIMS cases. Therefore, it is essential to implement a multidisciplinary approach to diagnose and treat patients suspicious of EIMS.

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.

Prevertebral Inflammatory Myofibroblastic Tumor Following COVID Vaccine Booster Dose

We report a case of a 30-year-old previously higid female presenting with dorsal pain and persistent fever after COVID-19 vaccine booster dose. CT and MR revealed a prevertebral heterogeneous and infiltrating mass, with spontaneous regression in control imaging which biopsy confirmed an inflammatory myofibroblastic tumor.

Laparoscopic excision of inflammatory pseudotumors: A case report

Inflammatory pseudotumors (IPs) are rare incidental benign lesions which can occur in any anatomical site. They have been reported by a variety of names, including inflammatory myofibroblastic tumor, histiocytoma, xanthoma, and plasma cell granuloma. Their knowledge is important because of the differential diagnosis with others true malignancies. Only 30 case reports are reported in the literature. Surgical resection is the mainstay of treatment with excellent outcomes and low recurrence rates. When anatomical site is suitable, a laparoscopic approach should be performed to minimize morbidity and expedite recovery. Here, we present a case report of IPs of antimesenteric bowel treated with a laparoscopic surgical approach.

18F-FDG PET/CT Imaging of G-CSF-Producing Inflammatory Myofibroblastic Tumor of the Pleura

ABSTRACT

We report a case of granulocyte colony-stimulating factor (G-CSF)-producing inflammatory myofibroblastic tumor of the pleura in a 71-year-old man. Contrast-enhanced CT demonstrated multiple pleural masses with pulmonary hilar lymph nodes swelling. 18F-FDG PET/CT demonstrated marked focal FDG uptake in the thoracic masses with diffuse uptake in the bone marrow. Based on the pathological findings and elevated serum G-CSF level, the patient was diagnosed as G-CSF-producing inflammatory myofibroblastic tumor. Because G-CSF-producing tumors demonstrate aggressive clinical course, early and accurate diagnosis is important.

A unique case of inflammatory myofibroblastic tumor of the liver manifesting with biloma: A case report

Anaplastic lymphoma kinase (ALK)-negative hepatic inflammatory myofibroblastic tumors (IMTs) harboring the ETS variant transcription factor 6-neurotrophic receptor tyrosine kinase 3 (ETV6-NTRK3) fusion gene and manifesting with biloma are extremely rare, and their biological behavior is unclear. The present study reports the case of a 45-year-old female with ALK-negative IMT of the liver harboring the ETV6-NTRK3 fusion gene and manifesting with biloma. Computed tomography of the abdomen confirmed the lesions to be a low-density mass, measuring 11.2×8.5×10.5 cm, located in the left lobe of the liver, and a lower-density mass, measuring 8.5×6.1×5.9 cm, located in the interior of the tumor. As the suspicion of a malignancy remained high, surgical resection of the left hepatic lobe, including the tumor, was undertaken. Intraoperatively, a tumor (12×10×9 cm), with an unclear boundary, incomplete capsule and fish-like texture, was found in the left lateral lobe of the liver, and a biloma, measuring 8×6 cm, was identified inside the tumor. Pathological examination revealed spindle cell proliferation with infiltration of chronic inflammatory cells and mucinous degeneration. Immunohistochemical studies showed negativity for ALK, CD117, CD34, discovered on GIST-1, desmin, smooth muscle actin, S-100, CD21, pan-cytokeratin, epithelial membrane antigen, CD23 and CD35, but positivity for vimentin staining, and 5% Ki-67-positive cells. Fluorescence in situ hybridization studies assessing characteristic genetic rearrangements using ALK, RET, ROS1, MDM2, MGEA5 and ETV6 break-apart assays, revealed the presence of the ETV6-NTRK3 fusion oncogene and negativity for ALK, RET, ROS1, MDM2 and MGEA5. The patient was discharged 7 days post-operatively, without any adjuvant treatment. No recurrence of symptoms was noted at the 3-year follow-up. To the best of our knowledge, this is the first report of biloma in an ALK-negative IMT of the liver, which may increase our understanding of hepatic IMT.

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

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm of intermediate malignancy. We describe the largest cohort of IMT patients to date, aiming to further characterize this rare, poorly understood tumor. This is a multi-institutional review of IMT patients ≤39 years, from 2000-2018, at 18 hospitals in the Pediatric Surgical Oncology Research Collaborative. 182 patients were identified with median age of 11 years. 33% of tumors were thoracic in origin. Presenting signs/symptoms included pain (29%), respiratory symptoms (25%), and constitutional symptoms (20%). Median tumor size was 3.9 cm. Anaplastic lymphoma kinase (ALK) overexpression was identified in 53% of patients. 7% of patients had distant disease at diagnosis. 91% of patients underwent resection: 14% received neoadjuvant treatment and 22% adjuvant treatment. 12% of patients received an ALK inhibitor. 66% of surgical patients had complete resection, with 20% positive microscopic margins, and 14% gross residual disease. Approximately 40% had en bloc resection of involved organs. Median follow-up time was 36 months. Overall 5-year survival (OS) was 95% and 5-year event-free survival (EFS) was 80%. Predictors of recurrence included respiratory symptoms, tumor size, and distant disease. Gross or microscopic margins were not associated with recurrence, suggesting that aggressive attempts at resection may not be warranted. This article is protected by copyright. All rights reserved.

Inflammatory myofibroblastic tumor: molecular landscape, targeted therapeutics, and remaining challenges

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor of intermediate malignant potential that predominantly affects children, adolescents and young adults. IMT has a predilection for the lung, abdomen, pelvis, and retroperitoneum, however, can affect any part of the body. IMT is typically localized, and multifocal or metastatic disease is uncommon. Complete surgical resection is the treatment of choice when feasible. There is no established standard of care for unresectable and advanced IMT. Approximately half of IMTs harbor anaplastic lymphoma kinase (ALK) gene rearrangements, and fusions involving ROS1, PDGFRβ, RET and NTRK have also been described. Given the molecular landscape of IMT, management of these tumors has evolved to include tyrosine kinase inhibitors and novel targeted therapeutics. This review highlights the molecular characteristics, evolution of targeted therapies and the remaining challenges in the management of IMT.

Inflammatory myofibroblastic tumors arising from pancreas head and peri-splenic area mimicking a malignancy

Inflammatory myofibroblastic tumors (IMTs) are a rare chronic inflammatory disease with unclear pathogenesis and pathological features that are not those of a malignant tumor. It is difficult to differentially diagnose them without surgical excision because of their unpredictable clinical behavior, which ranges from benign to locally invasive aggressiveness. We report two cases of IMTs that were diagnosed after surgery. In one case, the IMT originated in peri-splenic area in a 63-year-old female patient. The other case involved a 48-year-old female patient who suffered from an IMT of the head of the pancreas. Both of these cases did not require further treatment based on histological findings, and there has been no evidence of recurrence or metastasis so far. These cases show that the primary choice for the exact diagnosis and proper treatment of IMTs is complete surgical resection.

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.

Inflammatory pseudotumor secondary to urachal cyst: A challenging clinical case report

INTRODUCTION

There is a wide differential diagnosis for intraabdominal tumors. Surgical resection and microscopic analysis of tissue structure can identify tumor origin in most cases. Most rapidly growing invasive tumors are neoplastic. Inflammatory pseudotumors are a subcategory of intraabdominal tumors that are non-neoplastic and can be rapidly growing. Urachal cysts originate from the dome of the bladder; however they are typically not invasive. There is limited literature on the appropriate management of these tumors.

PRESENTATION

A 37-year-old female presenting with symptoms of abdominal pain was found to have a large intraabdominal mass invading multiple organs. Core biopsies demonstrated inflammation. The mass grew significantly over the course of a year and patient's abdominal pain worsened. The patient was taken to the operating room for resection. Final pathology revealed reactive fibrous tissue with acute and chronic inflammation invading bladder, urethra, abdominal wall, appendix, and ovary. Intraoperative frozen section demonstrated low grade spindle cells with concern for inflammatory pseudotumor but final pathology demonstrated inflammation.

DISCUSSION

Although benign, these tumors cause significant morbidity due to their size and level of organ invasion. Management should involve surgical resection as well as potential post-operative chemotherapy or NSAIDs based off clinical picture. We demonstrate the importance of close follow up for residual disease or recurrence of patients with inflammatory pseudotumors of the abdomen.

CONCLUSION

This case highlights difficulties in diagnosis of a tumor that has potential to cause significant morbidity. There is need for further research to discover the best management after surgical resection of these tumors.

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

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

Differentiation between inflammatory myofibroblastic tumor and cholangiocarcinoma manifesting as target appearance on gadoxetic acid-enhanced MRI

PURPOSE

To determine the differential features of inflammatory myofibroblastic tumor (IMT) and intrahepatic cholangiocarcinoma (ICC) manifesting as target appearance on gadoxetic acid-enhanced MRI.

METHODS

Twenty-seven patients with 36 IMTs (1.2-6.0 cm) and 34 patients with 34 ICCs (1.5-6.0 cm) who underwent gadoxetic acid-enhanced MRI were enrolled in this study. Two reviewers evaluated morphology, signal intensity, and enhancement features of tumors on T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and gadoxetic acid-enhanced imaging.

RESULTS

As for 32 IMTs with target appearance, IMTs most commonly demonstrated early target appearance characterized by a peripheral hypointense rim on unenhanced T1WI (n = 27, 84.4%), central enhanced area with a hypointense rim on arterial phase (AP) and portal venous phase (PVP) (n = 29, 90.6%), and transitional phase (TP) (n = 28, 87.5%). Meanwhile, most of the ICCs showed homogeneous hypointensity on T1WI (100%), a hyperenhancing rim on AP, late target appearance on TP (n = 32, 94.1%) and HBP (n = 32, 94.1%). Target appearance on DWI appearing as hyperintensity with central hypointense area was seen in 2 IMTs and 32 ICCs. On T2WI, 24 IMTs (n = 24, 75.0%) displayed central iso- and peripheral hyperintensity and 27 ICCs (84.4%) showed layered hyperintensity with either brighter or darker area in center. The remaining six IMTs with no target were observed as cystic appearing nodules (n = 3) or ill-defined hypovascular nodules (n = 2) and fibrotic mass (n = 1).

CONCLUSION

IMTs often show early target appearance on unenhanced T1WI, and early dynamic phases of gadoxetic acid-enhanced MRI. Target appearance on later phases, such as TP and HBP, and DWI target appearance were commonly in ICCs, but rare in IMTs.

Inflammatory myofibroblastic tumour: an unusual presentation including small bowel obstruction and palpable abdominal mass

A 41-year-old man with no medical history presented with 2 weeks of nausea, vomiting, a new palpable abdominal mass, constipation and a 14kgweight loss. On admission, CT abdomen and pelvis demonstrated a 6.9×3.7 cm soft-tissue abdominal mass deep to and invading the lower anterior abdominal wall with tethering of the urinary bladder and potential involvement of the urachus. Subsequently, a biopsy demonstrated a low-grade spindle cell neoplasm compatible with inflammatory myofibroblastic tumour with immunostain positive for smooth muscle actin and desmin and negative for CD21, CD117, DOG-1, TKE-1, mdm2, CD34 and ALK. One week following admission, he underwent en bloc excision of the mass including abdominal wall (umbilicus, portions of rectus sheath and muscle), bladder dome, right colon and a segment of small bowel. Final pathology of the mass confirmed an inflammatory myofibroblastic tumour, and his postoperative course was uneventful.

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.

Intra-abdominal inflammatory myofibroblastic tumour (IMT) mimicking gonadal mass in a male infant with undescended testes

Inflammatory myofibroblastic tumour (IMT) is a rare benign neoplastic tumour, originally described as an inflammatory pseudotumor. Only a single case of IMT in the spermatic cord associated with undescended testes has been reported. We present a rare case of abdominal IMT in a male infant with undescended bilateral testes. The abdominopelvic mass was suspected to be a gonadal malignancy due to empty scrotal sac but proved to be otherwise on histopathology. Mass was completely resected and orchiopexy was performed for both undescended normal-appearing testes. The patient developed a recurrent mass 2 months later involving the left spermatic cord and the left testicle. Radical surgery was performed with removal of the left testicle and spermatic cord. The patient was disease-free at 1-year follow-up.

Spontaneous regression of inflammatory myofibroblastic tumor of the orbit: A case report and review of literature

Inflammatory myofibroblastic tumor is a rare entity characterized by the presence of myofibroblasts and inflammatory cells within a fibrous stroma. It typically occurs in the pediatric population. The most common site of occurrence is the lung though it has been reported throughout the body. Although rare, it has been reported in the orbit. The clinical course is ill defined in the literature; here we report a case of pediatric IMT with delayed spontaneous regression.

Spontaneous Regression of Inflammatory Pseudotumor in the Cauda Equina: A Case Report

Spinal intradural extramedullary inflammatory pseudotumor (IPT) is an extremely rare entity. Spontaneous shrinking of a spinal IPT has never been reported. A case of an IPT of the cauda equina that regressed spontaneously is presented. A 78-year-old woman presented with hypoesthesia of both lower legs in the L4 nerve root distribution and motor weakness of the right leg. Preoperative CT myelography and MRI showed two tumor-like lesions located at T12-L1 and L2-3. The lesion at the T12-L1 level appeared to encase several nerve roots. The preoperative diagnosis was ependymoma, schwannoma, or malignant lymphoma. The tumors were biopsied. In the operation, the lesion turned out to consist of swollen and adherent nerve roots. On histopathological examination of the biopsied nerve roots, they were diagnosed as IPT. The patient's symptoms improved gradually without any treatment after the operation. The IPTs regressed on the postoperative MR images and disappeared at one year. This is the first report of spontaneous regression of an IPT in the spinal region. IPT should be considered in the differential diagnosis of a tumor that appears to involve several nerve roots on preoperative imaging, but surgery is necessary for diagnosis. Complete resection is not absolutely required if an intraoperative pathological diagnosis of the frozen section reveals IPT.

Inflammatory Myofibroblastic Tumor of Common Bile Duct in a Girl

Inflammatory myofibroblastic tumor (IMT) is a rare, low grade malignant lesion which can occur anywhere in the body. In children it is usually found in the visceral soft tissues with a potential for local invasion and recurrence, and rarely distant metastasis. We report the diagnostic dilemma faced in the management of a 12-year old girl who presented with obstructive jaundice with a mass lesion at the distal end of the common bile duct. She underwent a tumor resection with a bilio-enteric bypass followed by a course of oral steroids and celecoxib.

Remission of ALK-negative primary pulmonary inflammatory myofibroblastic tumor on treatment with clarithromycin: A case report and review of the literature

Inflammatory myofibroblastic tumors (IMTs) belong to an intermediate group of soft-tissue tumors, they are relatively rare but exhibit a wide range of pathologies, from benign to malignant. At present, no standard treatment has been established, however, it is known to be important to determine the grade of malignancy of the tumor, prior to treatment. The present study reports a 73-year-old female patient with no clinical manifestations, who, when examined radiographically at a health check exhibited bilateral thoracic infiltrative shadows and nodular shadows by chest CT. A metastatic tumor or an organizing pneumonia were suspected. Blood examination showed no abnormal findings, and a pathological diagnosis of IMT was given from the histological findings of the tissue extracted by video-assisted thoracic surgery. Histological analysis established the lack of expression of anaplastic lymphoma kinase (ALK1) and immunoglobulin subtype G4 (IgG4). Alteration of the radiological shadows was observed over several weeks, and after concluding that chronic inflammation was worsening the patient's condition, clarithromycin was administered as a long-term macrolide therapy. The IMT decreased in size, and eight months later it had almost resolved. The patient was last reported to be maintaining a stable condition with no relapse. Some IMT cases have malignant pathology, and should be carefully followed-up. However, in the present case, where the IMT is both ALK1-negative and IgG4-negative, its biological immune responsiveness appears to differ from positive cases, and an inflammatory response was predominant. Clarithromycin, has immunomodulatory and anti-inflammatory effects and appeared to be effective in treating the IMT of the patient in the present study.