Sudden death by massive systemic embolism from cardiac myxoma. Role of the clinical autopsy and review of literature

Detection, Prevention, and Treatment of Asymptomatic Myxoma in a Young Adult Patient: A Case Report

We present a case of myxoma originating from the right ventricular outflow tract. The patient was referred to our clinic after detecting a heart murmur at a routine school medical check-up, which is unique to Japan. He was treated with tumor resection and cryoablation to prevent recurrence. Cryoablation after tumor removal has the potential to prevent the recurrence of cardiac tumors. This case further emphasized the importance of regular school medical check-ups because it prevented sudden death.

Sudden cardiac death due to an obstructive large right atrial myxoma

Sudden cardiac death is a phenomenon that affects more than 200,000 individuals annually in the United States. Among sudden cardiac deaths, only a fractionally small portion is thought to be attributable to intracardiac neoplasms. Though rarely implicated as the primary cause of death, cardiac myxomas are the most common benign neoplasms of the heart and have been known to cause death due to multifactorial embolic events, fatal arrhythmias, and frank obstructive events. In this case, a healthy, asymptomatic young male was found unresponsive in his residence. Examination of the heart at autopsy revealed dilation of the right atrium and a large, hemorrhagic, irregular, and obstructing mass arising from the right atrium, consistent with cardiac myxoma. When unusual cardiac findings are discovered at autopsy, a systematic investigation of the heart, including retaining the organ for cardiac pathology consultation, is mandatory to correctly identify the cause of death.

Unusual Presentation of Cardiac Myxoma Mimicking Chronic Obstructive Pulmonary Disease (COPD) Exacerbation: A Report of a Rare Case

A cardiac myxoma is an authentic tumor that develops within the heart. Despite the typically benign histological characteristics, a cardiac myxoma may, on occasion, exhibit behavior reminiscent of malignant tumors. Most of these myxomas localize in the left atrium, often originating from a stalk near the foramen ovale region. The conventional presentation of cardiac myxomas includes a combination of obstruction, clot formation, and systemic symptoms, mirroring various other prevalent systemic diseases. They may manifest either spontaneously or through hereditary transmission. While familial myxomas are commonly linked to discernible genetic mutations, the precise molecular mechanisms underlying spontaneous myxomas remain somewhat enigmatic. Many individuals with myxomas may remain asymptomatic. However, should symptoms manifest, they can prove nonspecific and pose challenges in interpretation, particularly in instances of spontaneous heart myxomas. This report describes a 58-year-old female patient who presented with increasing severity of exertional dyspnea over a six-month duration. Initial differential diagnoses included common pulmonary and cardiac conditions, with a primary focus on chronic obstructive pulmonary disease and congestive heart failure. An echocardiogram revealed a large mass in the left atrium suggestive of a cardiac myxoma. Surgical resection confirmed the diagnosis. This case underscores the significance of including cardiac myxoma in differential diagnoses for progressive exertional dyspnea. Early detection and surgical intervention are crucial in mitigating potential complications like stroke, heart failure, or sudden cardiac death.

SARS-CoV-2-Related Olfactory Dysfunction: Autopsy Findings, Histopathology, and Evaluation of Viral RNA and ACE2 Expression in Olfactory Bulbs

BACKGROUND

The COVID-19 pandemic has been a health emergency with a significant impact on the world due to its high infectiousness. The disease, primarily identified in the lower respiratory tract, develops with numerous clinical symptoms affecting multiple organs and displays a clinical finding of anosmia. Several authors have investigated the pathogenetic mechanisms of the olfactory disturbances caused by SARS-CoV-2 infection, proposing different hypotheses and showing contradictory results. Since uncertainties remain about possible virus neurotropism and direct damage to the olfactory bulb, we investigated the expression of SARS-CoV-2 as well as ACE2 receptor transcripts in autoptic lung and olfactory bulb tissues, with respect to the histopathological features.

METHODS

Twenty-five COVID-19 olfactory bulbs and lung tissues were randomly collected from 200 initial autopsies performed during the COVID-19 pandemic. Routine diagnosis was based on clinical and radiological findings and were confirmed with post-mortem swabs. Real-time RT-PCR for SARS-CoV-2 and ACE2 receptor RNA was carried out on autoptic FFPE lung and olfactory bulb tissues. Histological staining was performed on tissue specimens and compared with the molecular data.

RESULTS

While real-time RT-PCR for SARS-CoV-2 was positive in 23 out of 25 lung samples, the viral RNA expression was absent in olfactory bulbs. ACE2-receptor RNA was present in all tissues examined, being highly expressed in lung samples than olfactory bulbs.

CONCLUSIONS

Our finding suggests that COVID-19 anosmia is not only due to neurotropism and the direct action of SARS-CoV-2 entering the olfactory bulb. The mechanism of SARS-CoV-2 neuropathogenesis in the olfactory bulb requires a better elucidation and further research studies to mitigate the olfactory bulb damage associated with virus action.

Crosstalk between KIF1C and PRKAR1A in left atrial myxoma

Cardiac myxoma (CM) is the most common benign cardiac tumor, and most CMs are left atrial myxomas (LAMs). Six variations of KIF1C, c.899 A > T, c.772 T > G, c.352 A > T, c.2895 C > T, c.3049 G > A, and c.*442_*443dup in left atrial myxoma tissues are identified by whole-exome sequencing (WES) and Sanger sequencing. RNA-seq and function experiments show the reduction of the expression of KIF1C and PRKAR1A caused by rare variations of KIF1C. KIF1C is observed to be located in the nucleus, bind to the promoter region of PRKAR1A, and regulate its transcription. Reduction of KIF1C decreases PRKAR1A expression and activates the PKA, which causes an increase in ERK1/2 phosphorylation and SRC-mediated STAT3 activation, a reduction of CDH1, TP53, CDKN1A, and BAX, and eventually promotes tumor formation both in vitro and in vivo. The results suggest that inhibition of KIF1C promotes the pathogenesis of LAM through positive feedback formed by the crosstalk between KIF1C and PRKAR1A.

Morphological characteristics of cardiac myxoma causing embolism: a series of 40 years of experience at a single institute

Systemic and cerebral embolisms are serious complications of associated with cardiac myxoma. Embolism risk reportedly depends on the gross and histological morphology. This study is aimed at analyzing the morphologic pattern of excised cardiac myxoma as a high-risk embolic cause. Between 1978 and April 2022, 116 surgical specimens of cardiac myxomas were recorded at the pathology department of our hospital. The tumors were classified into three types based on their macroscopic shapes and external morphology-round-smooth, irregular, and villous-to investigate the embolic complications. Of the 116 specimens, 106 macroscopic images of cardiac myxoma (89% were located in the left atrium) were prepared. Round-smooth types were found in 36 (34.0%) patients, irregular types in 32 (30.2%) patients, and the villous types in 38 (35.8%) patients. Multivariable analysis revealed that a villous external appearance was an independent predictor of embolic events (odds ratio: 8.7; 95% confidence interval: 2.4-42.1; p < 0.001). Villous external appearance of cardiac myxoma was associated with the highest risk of distal embolism.

Multimodality Imaging of Benign Primary Cardiac Tumor

Primary cardiac tumors (PCTs) are rare, with benign PCTs being relatively common in approximately 75% of all PCTs. Benign PCTs are usually asymptomatic, and they are found incidentally by imaging. Even if patients present with symptoms, they are usually nonspecific. Before the application of imaging modalities to the heart, our understanding of these tumors is limited to case reports and autopsy studies. The advent and improvement of various imaging technologies have enabled the non-invasive evaluation of benign PCTs. Although echocardiography is the most commonly used imaging examination, it is not the best method to describe the histological characteristics of tumors. At present, cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT) are often used to assess benign PCTs providing detailed information on anatomical and tissue features. In fact, each imaging modality has its own advantages and disadvantages, multimodality imaging uses two or more imaging types to provide valuable complementary information. With the widespread use of multimodality imaging, these techniques play an indispensable role in the management of patients with benign PCTs by providing useful diagnostic and prognostic information to guide treatment. This article reviews the multimodality imaging characterizations of common benign PCTs.

Dermatological and endocrine elements in Carney complex (Review)

Carney complex (CΝC) is a very rare, autosomal dominant, hereditary syndrome. Seventy percent of individuals with CNC have germline inactivating or deleting mutations of the CNC1 gene [currently known as protein kinase cAMP-dependent type I regulatory subunit α (PRKAR1A), located at the 17q22-24 chromosome level], with 30% of cases presenting with phosphodiesterase gene mutations. A member of the lentiginosis family, dermatological features include: skin pigmentation, cutaneous/mucosal myxomas, usually diagnosed by the age of 20 years (neonatal presentation is exceptional, requiring a meticulous differential diagnosis). Melanocyte-derived tumors such as epithelioid blue nevi (with different levels of pigmentation) and pigmented epithelioid melanocytoma (previously 'animal-type melanoma') are often found. Myxomas, mesenchymal tumors with mostly a benign pattern, may be recurrent. Primary cutaneous melanotic schwannoma are atypical, while non-skin sites are frequent. Corticotropinomas or somatotropinomas are part of the hereditary syndrome-related pituitary adenomas (representing 5% of all). Primary pigmented nodular adrenocortical disease involves bilateral cortical hyperplasia causing Cushing syndrome (CS) at an earlier age than non-CNC cases; osteoporotic fractures seem more prevalent compare to CS of other etiologies. Typically benign, a few cases of adrenocortical carcinoma have been identified. A total of 5% of familial non-medullary thyroid cancer is syndromic, also including CNC. CNC-related thyroid frame includes: hyperthyroidism, follicular hyperplasia/adenomas, follicular carcinoma (usually aggressive, bilateral or multifocal). Large cell calcifying Sertoli cell tumors of the testes have malignant behavior in adults; in children these may induce precocious puberty. Two particular mammary tumors are found: myxoid fibroadenomas and breast myxomatosis. Cutaneous/subcutaneous lesions, pigmented or not, or any focal swelling of non-identified cause needs careful examination, since dermatological elements are among the earliest and most discernable by which to detect lesions in CNC, a systemic condition with multi-level endocrine involvement.

Atrial Myxoma on Atrial Septal Defect Occlusion Device: A Rare but True Occurrence

•

Device occlusion is the method of choice to treat atrial septal defects.

•

Atrial myxoma on an atrial septal defect occlusion device is rare but does occur.

•

Echocardiography plays an essential role in confirming an atrial myxoma.

•

Echocardiography helps to exclude a left atrial thrombus.

•

Echocardiography contributes to surgical planning.