Autophagy in cardiac myxoma: An important puzzle piece in understanding its inflammatory environment.

BACKGROUND: Cardiac myxomas are rare, predominantly sporadic tumors that can cause heart failure and systematic inflammatory symptoms, and increase the risk of emboli. Their pathophysiology remains poorly understood, but intra-tumoral inflammation and senescence seem to be implicated in it. One of the principal cellular mechanisms implicated in tumor progression is autophagy, largely unknown in myxomas. Thus, our study aimed to investigate the presence of autophagic markers in myxomas and to correlate it with their immune microenvironment. METHODS: Twenty-five cardiac myxomas were studied for the autophagic markers LC3B and p62/sequestosome 1 and were compared with markers of the immune microenvironment. RESULTS: Most myxomas showed expression of both autophagic markers. We found a positive correlation between LC3B and PD-L1, as well as CD163, and a negative correlation between LC3B and CD8, CD20, CD138, and CD117 infiltration. CONCLUSION: Our data not only confirm the presence of autophagic markers within cardiac myxomas but also suggest a possible association with their immune microenvironment.

Senescence, immune microenvironment, and vascularization in cardiac myxomas.

AIMS: Cardiac myxomas are rare tumors of incompletely elucidated pathogenesis. The aim of this study is to explore the possible presence of a senescence phenotype in cardiac myxomas, associated with an inflammatory and vasculogenic tumor microenvironment. METHODS AND RESULTS: This is a retrospective study of 29 cardiac myxomas with immunohistochemical detection of various inflammatory, vascular, and senescence markers. We show that all myxomas contain tumor cells in senescence overexpressing p16, and a fraction of senescent endothelial cells. Macrophages are the principal inflammatory cell population, followed by cytotoxic T cells, with fewer plasma cells, mastocytes, and B lymphocytes. These populations are found in different intratumoral localizations. Larger tumor volume is associated with a lower percentage of myxoid matrix, higher cellularity, higher macrophage, and lower number of mast cells as well as higher PD-L1 expression by inflammatory cells. Higher vascular density is associated with higher percentage of B cells, a lower number of macrophages and higher number of mastocytes, and lower PD-L1 expression by inflammatory cells. Tumors with higher vascular density and higher cellularity show higher amounts of p16 senescent endothelial cells. CONCLUSIONS: Myxoma tumor cells are in senescence and reside inside a tumor microenvironment with a distinct inflammatory profile rich in macrophages and cytotoxic T cells, and a rich vasculature, probably attributed to a senescence-associated secretory phenotype.

Innate immunity in cardiac myxomas and its pathological and clinical correlations.

Cardiac myxomas are the most common benign cardiac tumor. We investigated the immunohistochemical properties of 11 surgically excised cardiac myxomas, in order to analyze the correlation between macrophages and mast cell populations and clinical parameters. CD68+/CD163-/iNOS- (M0) cells represent the most abundant macrophage phenotype; however, CD68+/CD163+ cells (M2) were also frequent. CD68+/iNOS+ (M1) elements were rare. Mast cells, defined as a population of c-kit (CD117)+ and/or tryptase+ cells were also detected. Statistical analysis showed significant correlations between c-kit (CD117)+ and tryptase, CD68 and erythrocyte sedimentation rate (ESR), ESR and red blood cell count (RBC), and prothrombin time and platelet count. The inverse correlation between RBCs in peripheral blood and ESR suggested that anemia associated with chronic inflammatory disease is a noncasual event in patients suffering from cardiac myxoma. Mechanical hemolysis may be only a minor component of anemia, according to the lack of correlation between echographic surface and RBCs. Moreover, tumor size did not correlate with ESR, showing that inflammatory state may depend from both tumor cells population and inflammatory infiltrate. In the future, modulation of macrophage polarization in cardiac myxomas might represent important therapeutic target.

Esophageal ulcer of unknown origin complicated by left atrial myxoma.

Myxoma induces the onset of paraneoplastic syndromes by excreting various humoral mediators and is therefore known to present with diverse symptoms. A 40-year-old woman was admitted to our hospital for the treatment of an esophageal ulcer, the cause of which could not be identified on various examinations. Notably, a left atrial tumor was incidentally found on chest enhanced computed tomography. The esophageal ulcer, which was intractable to conventional therapy, improved with the administration of 5-aminosalicylate, a drug known to inhibit IL-1ß. This inhibitory action effectively suppressed the development of myxoma-induced paraneoplastic syndrome.

Fever of unknown origin from a left atrial myxoma: an immunologic basis and cytokine association.

Myxoma is the most common primary tumor of the heart. The typical presentations include a triad of embolic phenomena, intracardiac flow obstruction, and constitutional symptoms. We report a case of cardiac myxoma presenting as prolonged fever. Leukocytosis with a left shift, anemia, and elevated C-reactive protein were noted. A large left atrial myxoma was found incidentally by chest computed tomography. The fever subsided after surgical removal of the myxoma. His elevated serum interleukin-4 (IL-4), IL-6, IL-12 p70, interferon-γ, and tumor necrosis factor-α returned to undetectable levels four days after surgery. Cardiac myxomas should be included in the differential diagnosis of prolonged fever, even though no typical symptoms could be found.

Clinical, histological and immunohistochemical features of ectomesenchymal chondromyxoid tumor.

OBJECTIVE: Ectomesenchymal chondromyxoid tumor is a rare oral soft tissue neoplasm that should be differentiated from other neural and chondromyxoid entities. The aim of this study was to report the clinical, histological, and immunohistochemical features of 3 additional cases of this condition. METHODS: Clinical data were obtained from the clinical records and all cases were evaluated through light microscopy and immunohistochemistry to cytokeratins, vimentin, S100 protein, desmin, smooth muscle actin, and glial fibrilary acidic protein. RESULTS: All 3 cases affected the tongue as a long-lasting submucosal swelling and were managed through conservative surgery. They all showed myxoid and chondroid histological patterns, and vimentin, S100, and glial fibrilary acidic protein immunoexpression. CONCLUSIONS: These findings reinforce the typical features of ectomesenchymal chondromyxoid tumor previously described, helping to confirm and establish the clinical, histopathological, and immunohistochemical profile of this uncommon lesion.

Expression of tenascin-c and CD44 receptors in cardiac myxomas.

BACKGROUND: Myxomas are the most frequent primary cardiac neoplasms. They have an abundant extracellular matrix rich in proteoglycans. Interactions between cells and matrix are very important in the development of tumors, but data about myxomas in this setting are scarce because of the rarity of such neoplasms. The expression of tenascin-c and hyaluran receptors in cardiac myxoma has never been investigated. Moreover, it is now well recognized that cells of cardiac myxoma differentiate along endothelial lines. METHODS: We have analyzed left atrial myxomas from 13 consecutive patients (six male and seven female, surgically treated), via immunohistochemical methods for the expression of molecules also implicated in angiogenesis in normal and pathological conditions, like tenascin-c and hyaluran receptors CD44s, CD44v5 and CD44v6. RESULTS: Our data suggest that tenascin-c and CD44s play a synergic and perhaps complementary role in development of cardiac myxomas. In particular, tenascin-c seems to promote aggregation of cells and differentiation in vascular structures, whereas CD44s receptors might be important for cellular motility. Cell proliferation rate in such tumors was very low (MIB-1 labeling index <1%) and uniform in all the areas of the neoplasms regardless of the presence of characteristic structures such as cords and rings of multinucleated cells or the expression of tenascin-c and CD44 receptors. CONCLUSIONS: This study shows that cardiac myxomas express in the extracellular matrix tenascin-c and on the cellular membranes of neoplastic cells the hyaluran receptor CD44s. Such molecules take part in the mechanism of development of the myxomas and might be in the future the target of nonsurgical treatments.

Superficial acral fibromyxoma: a clinicopathological study of new 41 cases from the U.K.: should myxoma (NOS) and fibroma (NOS) continue as part of 21st-century reporting?

BACKGROUND: Superficial acral fibromyxoma (SAF) remains poorly recognized by general pathologists and dermatopathologists, partly attributable to its relatively uncommon occurrence and recent documentation. OBJECTIVES: To examine a series of SAF and document the U.K. experience with this new entity. METHODS: We reviewed 771 tumours reported between 1970 and 2006 in seven different U.K. hospitals and coded as myxoma, not otherwise specified (NOS), fibroma (NOS) or dermatofibroma (NOS) presenting at acral sites. Forty-one cases of SAF were studied. RESULTS: The patients comprised 27 men and 14 women, age range 19-91 years (mean 50, median 47), presenting with a solitary mass or nodule with a mean size of 1.92 cm. The common clinical sites were the toes (n=29) and fingers (n=11) as well as the palm (n=1), with more than 75% of cases close to or involving the nail bed. All cases presented with a painless mass except for four cases where pain was the presenting complaint. A history of trauma was reported in only two cases. Histologically, all cases presented as proliferation of spindle-shaped and/or stellate cells with a storiform and fascicular pattern embedded in a fibromyxoid/collagenous stroma with conspicuous mast cells. Multinucleated cells were observed (n=22), increased number of blood vessels in the stroma and extravasation of red blood cells (n=4). The characteristic immunophenotype was CD34+, CD99+/-, epithelial membrane antigen+ focally/-, S100-, desmin-, smooth muscle actin-, HMB45- and cytokeratin-. CONCLUSIONS: We describe a large series of 41 cases of SAF showing that it is a distinct entity with typical clinical, histological and immunohistochemical features. Follow-up was available only in 12 patients, precluding a firm comment on recurrence. However, complete excision and follow-up review is recommended.

[Phospholipase A2, group IIa, as an earlier unknown immunohistological marker of cardiac myxoma].

Phospholipase A2, group IIA, gene expression has been analyzed in primary heart tumors. High expression has been demonstrated through several ways: reverse-transcriptase chain polymerase chain, Northern blotting hybridization at the RNA level and immunoblotting, immunohistochemical assay at the protein level. Human cardiac myxoma exhibits highly positive phospholipase A2, group IIA, immunophenotype (100% positive cases). The immunophenotype is unique among human primary cardiac tumors. Phospholipase A2, group IIA, can be proposed as a tissue marker for pathological examination after heart tumor resection.

The variations in the immunologic features and interleukin-6 levels for the surgical treatment of cardiac myxomas.

PURPOSE: In this study, we propose the existence of a relationship between cardiac myxomas and the immunologic features or interleukin-6 (IL-6), while also considering the optimal treatment of cardiac myxoma, especially "familial myxoma." METHODS: In a 19-year period at our hospital, 20 patients underwent 21 operations for cardiac myxomas. The immunologic features and the IL-6 levels were measured pre-operatively in 13 cases and post-operatively in 10 cases. A case of "familial myxoma" was diagnosed based on molecular genetic analyses. RESULTS: No patients died in the hospital. The tumor size correlated with the preoperative IL-6 and/or alpha1-globulin values (P < 0.05). In addition, all of the immunologic features and IL-6 levels normalized by 4 weeks after surgery. "Familial myxoma" demonstrated recurrence without showing increases in either the immunologic features, inflammatory signs, or serum IL-6 levels. CONCLUSIONS: Patients with cardiac myxoma should therefore be operated on immediately because the possibility that the tumor size might be large when IL-6 and/or alpha1-globulin values are high. In addition, cases of "familial myxoma" require careful observation and periodic echocardiography after surgery to identify any possible recurrence. Recently, molecular genetic analyses are therefore considered to be an important diagnostic tool for cardiac myxoma, especially "familial myxoma." Our "familial myxoma" case demonstrated a C769T PRKAR1a mutation, which has also been observed in other cases of "familial myxoma."

MPO-ANCA-associated pseudovasculitis in cardiac myxoma.

We describe a case of cardiac myxoma whose clinical presentation mimicked that of polyarteritis nodosa. The serum levels of MPO-ANCA and IL-6 were elevated on laboratory investigation and normalized after the removal of the tumor. We suggest that a 'true' vasculitic mechanism contributes to the pathogenesis of pseudovasculitis in cardiac myxoma.

Multiple cerebral aneurysms as delayed complication of left cardiac myxoma: a case report and review.

Left cardiac myxoma and also consecutive embolization into the brain is well documented, whereas the association of myxomas with multiple fusiform cerebral aneurysms is rare. We analyze 33 previously reported patients and present a case of a 43-year-old woman with multiple cerebral infarctions 2 years after resection of a recurrent myxoma in the left atrium. Cerebral angiography displayed multiple fusiform aneurysms of several cerebral arteries, including a giant aneurysm of the basilar artery. Serum level of interleukin-6 (IL-6) was highly elevated. The clinical, radiological and pathological features of these aneurysms are summarized. The pathogenesis, including the role of IL-6 in the formation of myxomatous aneurysms, is discussed.

Myxoid adrenocortical adenoma with a pseudoglandular pattern.

Myxoid changes rarely occur in adrenocortical adenomas and carcinomas. Only eight benign tumours with such features have been described thus far, five of which also had a prominent pseudoglandular component. We report an additional pseudoglandular myxoid adenoma of the adrenal gland detected in a 58-year-old male patient who developed mild hypertension. At surgery, a 4-cm mass was resected and found to contain cords and tubules of polygonal cells in a myxoid background. Limited areas of classical adrenocortical adenoma were detected in less than 20% of the tumour area. Lack of atypias and absence of mucin markers, together with an immunophenotype consistent with adrenal tumours (focal cytokeratin, vimentin, synaptophysin and alpha-inhibin immunoreactivities), led to a diagnosis of primary adrenocortical adenoma with an extensive pseudoglandular myxoid pattern. However, the differential diagnosis from metastatic well-differentiated adenocarcinomas, chordomas and retroperitoneal myxoid mesenchymal tumours (e.g. liposarcoma) may be difficult in the absence of a complete clinical history and a reliable immunoprofile. We strongly recommend staining of any myxoid or glandular tumour of the adrenal gland for alpha-inhibin and synaptophysin (probably the currently best characterised markers of adrenocortical origin) before considering alternative (probably more common) diagnoses of metastatic adenocarcinoma or retroperitoneal tumours localised to the adrenal gland.

Herpes simplex virus type 1 infection associated with atrial myxoma.

Some findings suggest an infectious factor in cardiac myxoma and certain histopathological features indicate herpes simplex virus type 1 (HSV-1) infection. We hypothesized that HSV-1 may be involved in the pathogenesis of cardiac myxoma. Paraffin-embedded tissue samples from 17 patients with atrial myxoma were investigated for HSV-1 antigen by immunohistochemistry and viral genomic DNA by nested polymerase chain reaction. The histogenesis and oncogenesis of atrial myxoma were assessed by the expression of calretinin, Ki67, and p53 protein, respectively. Autopsy myocardial samples, including endocardium from 12 patients who died by accident or other conditions, were used for comparison. HSV-1 antigen was detected in atrial myxoma from 12 of 17 patients: 8 of these 12 samples were positive also for HSV-1 DNA. No HSV-1 antigen or DNA was found in tissue from the comparison group. Antigens of HSV-2, varicella-zoster virus, Epstein-Barr virus, and cytomegalovirus were not found in atrial myxoma. Calretinin was found in myxoma cells of all 17 cases but Ki67 was present only in smooth muscle cells or infiltrating cells in some cases. p53 was not detectable in any myxoma. Most infiltrating cells were cytotoxic T lymphocytes. These data suggest that HSV-1 infection is associated with some cases of sporadic atrial myxoma and that these may result from a chronic inflammatory lesion of endocardium.

Cardiac myxomas: 24 years of experience in 49 patients.

OBJECTIVES: In this single-center study we reviewed our experience with a significant number of cardiac myxoma cases occurring over the past two decades. PATIENTS AND METHODS: Cardiac myxomas represented 86% of all surgically treated cardiac tumors at our center. Specifically, there were 49 consecutive patients, each with at least one myxoma. A detailed clinical, immunological, and echocardiographic long-term examination of 37 patients revealed one recurrent myxoma. RESULTS: Most myxomas originated from the left atrium (87.7%), but also much less frequently from the mitral valve (6.1%), from the right atrium (4.1%), and from the left and right atria (2.0%). The myxomas produced a prolapse into the left ventricle in 40.8% of the patients, mitral stenosis in 10.2%, and threatened left ventricular outflow tract obstruction in 2.0%. Multiple myxomas were found in 20.4% of the patients. Cardiac signs appeared in 93.9% of the patients. Preoperative embolic events had occurred in 26.5%. Immunologic alterations were present in 87.5%. For resection, a bilateral atriotomy was used. An additional aortotomy was needed to expose one mitral valve myxoma. Postoperatively, 81.1% of the patients remained without cardiac symptoms. The early mortality rate was 2.0% and the late mortality rate was 6.1%. Long-term prognosis was excellent with an actuarial survival rate of 0.74. Specific immunologic alterations were found in 71.4% of the patients. The actuarial freedom from reoperation of the myxoma was 0.96. The rate of reoperations was low with 2.0% after 24 years. CONCLUSIONS: Myxomas were usually detected and operated on in symptomatic patients. A high index of suspicion seems important for early diagnosis. Immunologic findings may play an additional role in confirming the diagnosis and the recurrence of a myxoma. Immediate surgical treatment was indicated because of the high risk of embolization or of sudden cardiac death. Also, a familial genesis must be excluded in myxoma patients.

The role of interleukin-6 in cases of cardiac myxoma. Clinical features, immunologic abnormalities, and a possible role in recurrence.

We performed this prospective study to evaluate the correlation of interleukin-6 serum levels with preoperative constitutional symptoms and immunologic abnormalities, and the possible role played by this cytokine in tumor recurrence. Eight patients with atrial myxoma were evaluated at our institution from July 1993 to November 1998. We measured their interleukin-6 serum levels by enzyme-linked immunosorbent assay method preoperatively and 1 and 6 months after surgery. Two of the cases involved recurrent tumor, 1 patient had undergone his 1st surgery at a different institution and died during the 2nd procedure, so his data were incomplete. Preoperatively the whole group of patients had elevated interleukin-6 serum levels. Although patients with a 1st occurrence of tumor demonstrated a positive correlation between interleukin-6 serum level and tumor size, the 2 patients with recurrent tumors appeared to have higher interleukin-6 levels regardless of tumor size. Once the tumor was surgically removed, interleukin-6 levels returned to normal values, and this was associated with regression of clinical manifestations and immunologic features. According to our study, the overproduction of interleukin-6 by cardiac myxomas is responsible for the constitutional symptoms and immunologic abnormalities observed in patients with such tumors and might also play a role as a marker of recurrence. This study also suggests that recurrent cardiac myxomas form a subgroup of cardiac myxomas with a highly intrinsic aggressiveness, as implied by their greater interleukin-6 production despite their smaller size. Further studies are needed to confirm these results.

Increased levels of antiphospholipid antibodies in a woman with left atrial myxoma and systemic embolisms.

We describe a case of a 45-y-old woman with a left atrial myxoma, mild to moderate constitutional symptoms and systemic embolisms. Increased levels of antiphospholipid antibodies were detected at admission to the hospital and were gradually normalized after the surgical removal of the tumor. It is known that myxomas have the peculiar ability to induce a systemic inflammatory state with constitutional symptoms, probably mediated by the production of inflammatory mediators in the tumor. This case suggests that myxomas might have also been implicated in the production of antiphospholipid antibodies. Antiphospholipid antibodies could be just a by-product of the systemic inflammatory response. However, they could also have a role in the thrombosis on the myxoma surface and systemic embolisms.