Fibroma and inflammatory myofibroblastic tumor of the heart

Cardiac fibroma: A clinicopathologic study of a series of 12 cases

BACKGROUND

Cardiac fibroma (CF) is a rare tumor that has not been widely reported. This study investigated the clinical findings, histologic features, and differential diagnosis of CF.

METHODS

A total of 12 CF cases were studied and reviewed using hematoxylin and eosin (H&E), special staining and immunohistochemical staining. The ALK gene was tested in 4 cases of cardiac fibroma with significant inflammatory cells. Clinicopathological data were retrospectively analyzed and followed up.

RESULTS

The cases occurred in six males and six females ranging in age from 0.5 to 55 years (median, 5 years). The tumors were grossly single and solid (1-17 cm; mean 5.6 cm). The clinical signs and symptoms depended largely on the location of the tumor. Microscopically, the CFs observed were composed of monomorphic spindle cells and abundant collagen. The spindle cells demonstrated little or no atypia. The histology of CFs in infants and young children showed some differences from those in adults. Infants and young children with fibromas exhibited cellular types with more inflammatory infiltration. All tumors expressed vimentin markers. Eleven of 12 cases (91.7%) were positive for SMA by immunohistochemistry. ALK immunostaining and ALK-FISH tests showed negative results. Follow-up information was available for all patients. The mean postoperative follow-up was at 3 years (range 2 months-8.8 years). All patients were alive with no evidence of disease.

CONCLUSIONS

Our study shows that CFs exhibit a wide morphological spectrum of soft tissue tumors with fibroblastic or myofibroblastic differentiation and/or components. Infants and younger pediatric patients with fibromas have tumors that are more hypercellular and more likely to be misdiagnosed with aggressive or malignant lesions than adults. Finally, the data indicate that CF exhibits benign behavior and that local resection is safe and effective.

Infantile inflammatory myofibroblastic tumors: clinicopathological and molecular characterization of 12 cases

Inflammatory myofibroblastic tumors arising in infants are rare, poorly investigated and mostly reported as isolated cases or as a part of larger series thus, their clinicopathological and molecular features are essentially unknown. Archival files from two large pediatric institutions and a tumor registry were queried for pediatric inflammatory myofibroblastic tumors. Available material from patients ≤12 months of age was reviewed. Additional immunostains (ALK-1, D240, WT1) and ALK-FISH studies were performed as needed. Targeted anchored multiplex PCR with next-generation sequencing was done in all cases. A total of 12 of 131 infantile cases (mean 5.5 months) were identified (M:F of 2:1). Anatomic locations included intestinal/mesenteric (n = 6), head/neck (n = 3), and viscera (n = 3). Half of tumors showed a hypocellular myxoid pattern, perivascular condensation, and prominent vasculature with vague glomeruloid structures present in four of them. The remaining cases exhibited a more cellular pattern with minimal myxoid component. ALK-1 immunohistochemistry was positive in most cases (11/12) with cytoplasmic-diffuse (n = 6), cytoplasmic-granular (n = 2), and dot-like (n = 3) staining patterns. ALK fusion partners identified in five cases included EML4, TPM4, RANBP2, and a novel KLC1. Three inflammatory myofibroblastic tumors showed fusions with other kinases including TFG-ROS1 and novel FN1-ROS1 and RBPMS-NTRK3 rearrangements. Favorable outcome was documented in most cases (10/11) with available follow-up (median 17 months) while three patients were successfully treated with crizotinib. In summary, infantile inflammatory myofibroblastic tumors are rare and can exhibit paucicellular, extensively myxoid/vascular morphology with peculiar immunophenotype mimicking other mesenchymal or vascular lesions. All tumors harbored kinase fusions involving ALK, ROS1, and NTRK3 including three novel fusion partners (KLC1, FN1, and RBPMS, respectively). A favorable response to crizotinib seen in three cases supports its potential use in infants as seen in older patients. Awareness of these unusual morphologic, immunophenotypic, and molecular features is critical for appropriate diagnosis and optimized targeted therapy.

Subendocardial nodular proliferation of myofibroblasts in a laboratory beagle

A smooth white focus was macroscopically observed in the right ventricular endocardium in a 15-month-old male beagle from a 4-week oral gavage toxicity study. This lesion likely arose from myofibroblasts and was diagnosed as subendocardial nodular proliferation of myofibroblasts. This lesion was observed only in one animal in a low dose group and was an incidental finding. Histopathologically, the well-demarcated nodule comprised abundant collagen containing spindle cells arranged in intermediate to long streams and formed broad interlacing fascicles. The spindle cells had an indistinct cell border with round to elongated hyperchromatic nuclei or nuclei with finely stippled chromatin and indistinct nucleoli. Furthermore, these cells were weakly positive for S100 and positive for α-smooth muscle actin, calponin, and vimentin. Based on the histological features, the proliferating spindle cells resembled phenotypes of smooth muscles or myofibroblasts. However, the proliferating cells lacked well-differentiated smooth muscle cells, cigar-shaped nuclei, and well-developed reticulin fibers outlining individual cells. This study describes the morphological characteristics of an endocardial proliferative lesion in the right ventricle of a beagle.

Infantile Myofibroma Presenting as a Large Ulcerative Nodule in a Newborn

The differential diagnosis of a congenital cutaneous vascular-appearing mass in a newborn is broad and includes both benign and malignant tumors. We report the case of a newborn who presented with an erythematous exophytic skin nodule on the right upper leg. Excision was performed due to ulceration, concern for bleeding, and for diagnosis. Pathology revealed the mass to be an infantile myofibroma. This case highlights the importance of considering a broad differential diagnosis in a newborn with a cutaneous mass. While history, physical exam, and imaging can help diagnose some cases, a biopsy or excision is often needed to distinguish benign lesions from more concerning lesions.

Paroxysmal Nocturnal Dyspnea Secondary to Right Ventricular Myxoma: A Novel Presentation of an Unusual Tumor

A 14-month-old male presented with paroxysmal nocturnal dyspnea and grade III/VI systolic ejection murmur at the upper left sternal border with an S4 gallop and was subsequently found to have a right ventricular cardiac myxoma. Prior presentations of these tumors have been with exertional syncope and murmur, asymptomatic murmur, or exertional dyspnea; the presentation of such a tumor with paroxysmal nocturnal dyspnea is novel.

Inflammatory Myofibroblastic Tumor of the Heart in the Infant: Review of the Literature

Primary heart tumors are extremely rare, constituting approximately 0.02% of all malignancies. Inflammatory myofibroblastic tumor (IMT) constitutes <5% of primary heart tumors. Until now, IMT of the heart has been described in 21 infants below 1 year of age. Its etiology remains unknown. IMT usually develops within the right atrial and ventricular endocardium. The main clinical symptoms reported in the affected infants involved increasing respiratory failure, cyanosis, and heart murmurs. Histopathologically, IMT is characterized by the myofibroblast proliferation with inflammatory infiltrates composed of plasmocytes, lymphocytes, and histiocytes. Tumor resection is the treatment of choice in IMT. Such tumor location is associated with the high risk of perioperative failure. Steroid therapy and chemotherapy is reported in the literature as a nonsurgical treatment alternative. Here, we present a review of clinical symptoms, diagnostic and treatment options, based on published case reports of IMT in infants, including our 11-month-old patient with IMT located within the pericardium.

Inflammatory myofibroblastic tumour

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

Cardiac Inflammatory Myofibroblastic Tumor

Although inflammatory myofibroblastic tumors (IMTs) can be found in virtually every major organ, cardiac origin is rare. After recently providing care to a child who presented with a significant myocardial infarction, interest in this rare tumor was piqued. We describe a comprehensive review of cardiac IMT, including information on nomenclature, epidemiology, clinical features, pathogenesis, gross/histological features, immunohistochemical profile, diagnosis, treatment, and prognosis. Fifty-seven cases were identified in the literature. Interestingly, our case represents the seventh case of coronary artery involvement reported. Moreover, it was found that an initial presentation of sudden death most commonly involves the coronary arteries.

Inflammatory myofibroblastic tumor of the aortic valves causing sudden cardiac death: a case report and review of the literature

Cardiac inflammatory myofibroblastic tumor (IMT) is a rare entity affecting predominantly infants, children, and young adults. Although most tumors have a benign clinical course after complete surgical resection, some have significant clinical effects. We report the case of a 9-year-old girl who had sudden cardiac death as a result of occlusion of the left circumflex coronary artery. A review of 57 cases of cardiac IMTs reported in the literature in terms of epidemiology, clinical presentation, histologic and immunohistologic features, and outcome is presented. Recognition of this rare abnormality is important in order to initiate prompt surgical intervention.

Massive pericardial effusion caused by "inflammatory myofibroblastic tumour" in a 3-month-old child

Tumours originating from cardiac tissues are rarely encountered during childhood, and fortunately most of these tumours are benign in nature. Inflammatory myofibroblastic tumour, which has unique clinical, pathological, and molecular characteristics, is a relatively new entity compared with previously mentioned tumoural processes originating from the heart. Most of the cardiac intima-media thickness patients are in the age group of 4 months to 17 years. This rarely seen tumoural process has not been subject of any specific research and the prognosis is not well known. Here we present the case of a 3-month-old child who was admitted to our outpatient clinic with massive pericardial effusion and who has shown excellent progress after surgical resection of over 1 year.

Unusual case of pancreatic inflammatory myofibroblastic tumor associated with spontaneous splenic rupture

Background

Spontaneous splenic rupture considered a relatively rare but life threatening. The three commonest causes of spontaneous splenic rupture are malignant hematological diseases, viral infections and local inflammatory and neoplastic disorders. We describe a unique and unusual case of inflammatory myofibroblastic tumor of the tail of pancreas presented with massively enlarged spleen and spontaneous splenic rupture.

Case presentation

A 19 years old male patient with no significant past medical history presented to emergency room with abdominal pain and fatigue. Massively enlarged spleen was detected. Hypotension and rapid reduction of hemoglobin level necessitated urgent laparatomy. About 1.75 liters of blood were found in abdominal cavity. A large tumor arising from the tail of pancreas and local rupture of an enlarged spleen adjacent to the tumor were detected. Distal pancreatectomy and splenectomy were performed. To our knowledge, we report the first case of massively enlarged spleen that was complicated with spontaneous splenic rupture as a result of splenic congestion due to mechanical obstruction caused by an inflammatory myofibroblastic tumor of the tail of pancreas. A review of the literature is also presented.

Conclusion

Inflammatory myofibroblastic tumor of the tail of pancreas should be included in the differential diagnosis of the etiological causes of massively enlarged spleen and spontaneous splenic rupture.

Inflammatory myofibroblastic tumor of the right atrium

Cardiac inflammatory myofibroblastic tumor (IMT) is a rare entity and is associated with distinct clinical, pathological and molecular features. The clinical behavior, natural history, biological potential, management and prognosis of such tumors are unclear. We present herewith an adolescent girl who presented with similar entity involving the junction of the right atrium and the inferior vena cava (IVC) in association with thrombocytosis and IVC thrombosis leading to obstruction of blood flow. Diagnostic tools included imaging and immuno-histopathology studies. Surgical management included resection of the tumor and thrombo-embolectomy of the IVC under cardiopulmonary bypass. This case is unique due to association of complete obstruction of IVC caused by the strategic location of the tumor, thrombosis of vena cava and association of thrombocytosis. These features have not been reported yet in relation to the cardiac IMT. This report will help in better understanding and management of similar cases in terms of planning cannulation of femoral veins or application of total hypothermic circulatory arrest during cardiopulmonary bypass and prompt us to look for recurrence or metastasis during follow up using echocardiography and laboratory investigations. The possibility of IMT should be kept in the differential diagnosis of cardiac tumors especially in children and adolescents.

Beta-catenin mutations do not contribute to cardiac fibroma pathogenesis

Cardiac fibromas are the 2nd most common benign cardiac tumor occurring in children and bear a striking morphologic resemblance to soft tissue or desmoid fibromatosis. Since activating mutations in beta-catenin are common in desmoid fibromatosis as well as other spindle cell proliferations, the aim of our study was to determine if such mutations could be identified in cardiac fibroma. Nine cardiac fibromas from patients with surgical resection were examined for beta-catenin mutations by immunoperoxidase staining for beta-catenin protein and DNA sequencing of a region in exon 3 of the beta-catenin gene, where relatively conserved mutations have been described in desmoid fibromatosis. The mean age of the patients was 7.6 years (range: 10 weeks to 27 years), and 6 of the patients were male. No nuclear staining for beta-catenin was seen in the fibroma cells by immunoperoxidase methods. The beta-catenin exon 3 sequence data showed no mutations in any of the 9 tumors. We conclude that despite their morphologic similarity, cardiac fibroma and desmoid fibromatosis do not share this common molecular pathway of neoplastic growth.

Cardiac Inflammatory Myofibroblastic Tumor: A “Benign” Neoplasm That May Result in Syncope, Myocardial Infarction, and Sudden Death

Cardiac tumors other than myxomas are rare. We report a series of 10 intracavitary polypoid myofibroblastic proliferations in children and young adults emphasizing gross, histologic, and clinical features. There were 6 females and 4 males, with a mean age of 10 years (range 5 wk to 21 y). All lesions were endocardial-based, located in the right atrium (1), right ventricular inflow/tricuspid valve (1), right ventricular outflow (3), mitral valve (3), aortic valve/left coronary sinus (1), and left ventricular free wall (1). Symptoms included shortness of breath or dyspnea (3), syncope (2), chest pain (1), transient ischemic attacks (1), and fever with myalgias (1). All tumors were surgical resections, except 1 tumor that resulted in sudden coronary death and that was diagnosed at autopsy, and 1 tumor that embolized into the coronary artery and was treated by cardiac transplant. Two tumors, present in the aortic and mitral valves, respectively, caused cardiac ischemia. The tumors were polypoid or filiform and histologically resembled inflammatory myofibroblastic tumors of extracardiac sites, with loose spindle cell growth with sparse inflammation. Although there were frequent collagen bundles interspersed among the tumor cells, there were no large areas of dense fibrosis. Surface fibrin was present on the polypoid projections in 7 cases. Symptoms resulted from prolapse into coronary ostia or embolization, but no patient developed metastasis. Long-term follow-up in 2 patients demonstrated no evidence of disease or recurrence. Although metastatic potential was not identified, these tumors may result in serious symptoms, including myocardial infarct, syncope, and sudden death. These cardiac myofibroblastic tumors are readily distinguished from other endocardial-based cardiac tumors, including papillary fibroelastoma and myxoma, which may present clinically in the same manner.

Intracardiac inflammatory myofibroblastic tumor: a unique presentation

Cardiac tumors are detected rarely in childhood. These are most frequently found in infancy, and most are rhabdomyomas. We describe a unique occurrence of a rarely described intracardiac tumor in an asymptomatic 7-year-old child.

A calcified cardiac mass

Cardiac fibromas are benign tumours, often diagnosed in childhood, but rarely they may be diagnosed in adults or the elderly. We present an interesting case of a middle-aged lady presenting with exertional chest pain and breathlessness, who was found to have a heavily calcified mass within the myocardium. With a previous history of chest trauma, a calcified myocardial haematoma was initially suspected. Complete surgical excision led to a total resolution of symptoms. Histological examination confirmed the diagnosis of a cardiac fibroma. Complete excision of cardiac fibromas, where possible, is advised and is associated with excellent survival.

Heart tumors in children and adults: clinicopathological study of 59 patients from a surgical center

BACKGROUND

Heart tumors are rare lesions with variegated histological types. Their clinicopathological features could be more comprehensively categorized.

METHODS

This is a 19-year retrospective study of 17 infants/toddlers (<2 years of age) and 42 patients aged between 14 and 79 years (mean = 51.5) in a surgical center.

RESULTS

Congenital tumors (n = 17; 29%), including rhabdomyomas (n = 9), ventricular fibromas (n = 6), and hemangiomas (n = 1), required surgery mainly because of mass effect. Familial myofibromatosis was the only embolic congenital lesion. Acquired benign tumors (n = 28; 47%) included myxomas (n = 21), fibroelastomas (n = 3), myofibroblastic inflammatory tumors (n = 2), and lipomas (n = 2). Eight (29%) were revealed by systemic embolization. These benign noncongenital tumors were all treated by complete resection, except for an incompletely resected lipoma of the mitral valve. Postoperative arrhythmia (n = 1) and pericardial effusion (n = 3) were the only complications. Primary sarcomas (n = 8; 14%) were mostly vascular tumors (five of eight), and patients with high-grade tumors had a mean survival of 15 months (n = 5). Cardiac metastases (n = 6; 10%) were from carcinomas (n = 3) or sarcomas (n = 3); apart from a necrotic metastasis, all patients died (mean survival of 6 months).

CONCLUSIONS

This study shows that, regardless of patients' age, heart tumors can be classified as: (a) congenital lesions, which are spontaneously nonprogressive or regressive lesions possibly requiring surgery mainly because of mass effect; (b) acquired benign tumors, which are lesions requiring surgery often because of embolization risk; and (c) primary and secondary malignant tumors, which are lesions with globally poor prognosis but with some indications for resection.

Multiple Cardiac Inflammatory Myofibroblastic Tumors in the Right Ventricle in an Infant

Reported is the successful treatment of a 2-month-old boy with multiple inflammatory myofibroblastic tumors in the right ventricle protruding into the right atrium through the tricuspid annulus. The patient underwent subtotal excision on cardiopulmonary bypass with no intraoperative or postoperative complications. Cardiac inflammatory myofibroblastic tumors are rare lesions, and surgical resections in patients as young as 2 months have not been previously described. In this report we review the relevant literature and discuss the prevalence, histology, pathogenesis, clinical manifestations, diagnosis, differential diagnosis, and treatment of cardiac inflammatory myofibroblastic tumor.

Endocardial location of familial myofibromatosis revealed by cerebral embolization: cardiac counterpart of the frequent intravascular growth of the disease?

Myofibromatosis is a rare infantile benign neoplasia, which may involve the heart in the rare and usually fatal generalized form of the disease. Diagnosis of endocardial myofibromas was made on two surgically excised lesions of the mitral valve that were reveled by a cerebral embolization in a 12-month-old female infant. Surprisingly, the patient had no other obvious lesion of myofibromatosis. However, her father had a histologically proven neonatal history of myofibromatosis. This case confirms the likely autosomal dominant mode of inheritance of myofibromatosis. It highlights the embolization risk of the previously unreported endocardial location. We suggest that these clinically isolated non-invasive endocardial myofibromas did not represent a true visceral form of myofibromatosis. They were, rather, similar to the frequent intravascular growth of the disease.

Role of magnetic resonance imaging for evaluation of tumors in the cardiac region

The aim of this study was to review the role of MRI in the assessment of heart neoplasm, 25 cases with heart neoplasm (10 myxoma, 6 rhabdomyoma, 5 angiosarcoma, 2 mesothelioma, 1 lymphoma, and 1 fibroma) were examined with MRI and echocardiography. Multislice T1- and T2-weighted spin-echo images and static gradient-echo images were taken in appropriate directions with electrocardiogram gating. Gadolinium enhancement was performed in 21 cases. Transthoracic echocardiography was performed in all cases. Except for the 5 patients with rhabdomyoma, the pathological diagnosis was obtained. MRI proved to be useful for tissue characterization of myxoma, angiosarcoma, mesothelioma, and fibroma in cases with tuberous sclerosis. MRI also proved to be useful for detection of the tumor, depiction of contour, relation with other cardiac structures, in cases with myxoma, angiosarcoma, mesothelioma, lymphoma, and fibroma. In the differential diagnosis, MRI provided important information in cases with myxoma, rhabdomyoma, angiosarcoma, and fibroma. In cases with tumors expanding into the mediastinum, such as mesothelioma and fibroma in this report, MRI was useful in determining the location and border. In cases with tumors adjacent to pericardium, MRI was useful in detecting pericardial invasion. Gadolinium enhancement added useful information in cases with myxoma, rhabdomyoma, angiosarcoma, and mesothelioma. The role of MRI with and without Gd enhancement differs somewhat in individual types of heart neoplasm, and adaptation must be considered in each kind of neoplasm. On the other hand, MRI is an essential examination in all cases with a cardiac mass, which has not been diagnosed, since it may provide useful information for the differential diagnosis.