Resolving the heterogeneous tumour microenvironment in cardiac myxoma through single-cell and spatial transcriptomics.

BACKGROUND: Cardiac myxoma (CM) is the most common (58%-80%) type of primary cardiac tumours. Currently, there is a need to develop medical therapies, especially for patients not physically suitable for surgeries. However, the mechanisms that shape the tumour microenvironment (TME) in CM remain largely unknown, which impedes the development of targeted therapies. Here, we aimed to dissect the TME in CM at single-cell and spatial resolution. METHODS: We performed single-cell transcriptomic sequencing and Visium CytAssist spatial transcriptomic (ST) assays on tumour samples from patients with CM. A comprehensive analysis was performed, including unsupervised clustering, RNA velocity, clonal substructure inference of tumour cells and cell-cell communication. RESULTS: Unsupervised clustering of 34 759 cells identified 12 clusters, which were assigned to endothelial cells (ECs), mesenchymal stroma cells (MSCs), and tumour-infiltrating immune cells. Myxoma tumour cells were found to encompass two closely related phenotypic states, namely, EC-like tumour cells (ETCs) and MSC-like tumour cells (MTCs). According to RNA velocity, our findings suggest that ETCs may be directly differentiated from MTCs. The immune microenvironment of CM was found to contain multiple factors that promote immune suppression and evasion, underscoring the potential of using immunotherapies as a treatment option. Hyperactive signals sent primarily by tumour cells were identified, such as MDK, HGF, chemerin, and GDF15 signalling. Finally, the ST assay uncovered spatial features of the subclusters, proximal cell-cell communication, and clonal evolution of myxoma tumour cells. CONCLUSIONS: Our study presents the first comprehensive characterisation of the TME in CM at both single-cell and spatial resolution. Our study provides novel insight into the differentiation of myxoma tumour cells and advance our understanding of the TME in CM. Given the rarity of cardiac tumours, our study provides invaluable datasets and promotes the development of medical therapies for CM.

Genetic characterization of intramuscular myxomas.

Introduction: Intramuscular myxomas are benign tumors that are challenging to diagnose, especially on core needle biopsies. Acquired chromosomal aberrations and pathogenic variants in codon 201 or codon 227 in GNAS complex locus gene (GNAS) have been reported in these tumors. Here we present our genetic findings in a series of 22 intramuscular myxomas. Materials and methods: The tumors were investigated for the presence of acquired chromosomal aberrations using G-banding and karyotyping. Pathogenic variants in codon 201 or codon 227 of GNAS were assessed using direct cycle Sanger sequencing and Ion AmpliSeq Cancer Hotspot Panel v2 methodologies. Results: Eleven tumors carried chromosomal abnormalities. Six tumors had numerical, four had structural, and one had both numerical and structural chromosomal aberrations. Gains of chromosomes 7 and 8 were the most common abnormalities being found in five and four tumors respectively. Pathogenic variants in GNAS were detected in 19 myxomas (86%) with both methodologies. The detected pathogenic variants were p.R201H in nine cases (seven with abnormal and two with normal karyotypes), p.R201C in five cases, all with normal karyotypes, p.R201S in three cases (two with abnormal and one with normal karyotype), p.R201G in one case with a normal karyotype, and p.Q227E in one case with a normal karyotype. Conclusion: Firstly, our data indicate a possible association between chromosomal abnormalities and GNAS pathogenic variants in intramuscular myxomas. Secondly, the presence of the rare pathogenic variants R201S, p.R201G and p.Q227E in 26% (5 out of 19) of myxomas with GNAS pathogenic variants shows that methodologies designed to detect only the common "hotspot" of p.R201C and p.R201H will give false negative results. Finally, a comparison between Ion AmpliSeq Cancer Hotspot Panel v2 and direct cycle Sanger sequencing showed that direct cycle Sanger sequencing provides a quick, reliable, and relatively cheap method to detect GNAS pathogenic variants, matching even the most cutting-edge sequencing methods.

Carney complex predisposes to breast cancer: prospective study of 50 women.

OBJECTIVE: Carney complex (CNC) is a rare genetic syndrome, mostly due to germline loss-of-function pathogenic variants in PRKAR1A. Carney complex includes pigmented skin lesions, cardiac myxomas, primary pigmented nodular adrenocortical dysplasia, and various breast benign tumors. DESIGN: The present study was designed to describe the characteristics of breast lesions in CNC patients and their association with other manifestations of CNC and PRKAR1A genotype. METHODS: A 3-year follow-up multicenter French prospective study of CNC patients included 50 women who were analyzed for CNC manifestations and particularly breast lesions, with breast imaging, genotyping, and hormonal settings. RESULTS: Among the 38 women with breast imaging, 14 (39%) had breast lesions, half of them bilateral. Ten women (26%) presented with benign lesions and six with breast carcinomas (16%): one had ductal carcinoma in situ at 54, and five had invasive cancer before 50 years old, whom one with contralateral breast cancer during follow-up. The occurrence of breast cancer was more frequent in women with PRKAR1A pathogenic variant odds ratio = 6.34 (1.63-17.91) than in general population of same age. The mean age at breast cancer diagnosis was 44.7 years old: 17 years younger than in the general population. Breast cancer patients had good prognosis factors. All breast carcinomas occurred in individuals with familial CNC and PRKAR1A pathogenic variants. Loss of heterozygosity at the PRKAR1A locus in the 2 invasive breast carcinomas analyzed suggested a driver role of this tumor suppressor gene. CONCLUSIONS: As CNC could predispose to breast carcinoma, an adequate screening strategy and follow-up should be discussed in affected women. CLINICAL TRIAL REGISTRATION: ClinicalTrial.gov NCT00668291.

The benign nature and rare occurrence of cardiac myxoma as a possible consequence of the limited cardiac proliferative/ regenerative potential: a systematic review.

BACKGROUND: Cardiac Myxoma is a primary tumor of heart. Its origins, rarity of the occurrence of primary cardiac tumors and how it may be related to limited cardiac regenerative potential, are not yet entirely known. This study investigates the key cardiac genes/ transcription factors (TFs) and signaling pathways to understand these important questions. METHODS: Databases including PubMed, MEDLINE, and Google Scholar were searched for published articles without any date restrictions, involving cardiac myxoma, cardiac genes/TFs/signaling pathways and their roles in cardiogenesis, proliferation, differentiation, key interactions and tumorigenesis, with focus on cardiomyocytes. RESULTS: The cardiac genetic landscape is governed by a very tight control between proliferation and differentiation-related genes/TFs/pathways. Cardiac myxoma originates possibly as a consequence of dysregulations in the gene expression of differentiation regulators including Tbx5, GATA4, HAND1/2, MYOCD, HOPX, BMPs. Such dysregulations switch the expression of cardiomyocytes into progenitor-like state in cardiac myxoma development by dysregulating Isl1, Baf60 complex, Wnt, FGF, Notch, Mef2c and others. The Nkx2-5 and MSX2 contribute predominantly to both proliferation and differentiation of Cardiac Progenitor Cells (CPCs), may possibly serve roles based on the microenvironment and the direction of cell circuitry in cardiac tumorigenesis. The Nkx2-5 in cardiac myxoma may serve to limit progression of tumorigenesis as it has massive control over the proliferation of CPCs. The cardiac cell type-specific genetic programming plays governing role in controlling the tumorigenesis and regenerative potential. CONCLUSION: The cardiomyocytes have very limited proliferative and regenerative potential. They survive for long periods of time and tightly maintain the gene expression of differentiation genes such as Tbx5, GATA4 that interact with tumor suppressors (TS) and exert TS like effect. The total effect such gene expression exerts is responsible for the rare occurrence and benign nature of primary cardiac tumors. This prevents the progression of tumorigenesis. But this also limits the regenerative and proliferative potential of cardiomyocytes. Cardiac Myxoma develops as a consequence of dysregulations in these key genes which revert the cells towards progenitor-like state, hallmark of CM. The CM development in carney complex also signifies the role of TS in cardiac cells.

Whole genome sequencing resolves 10 years diagnostic odyssey in familiar myxoma.

Carney complex (CNC) is an ultrarare disorder causing cutaneous and cardiac myxomas, primary pigmented nodular adrenocortical disease, hypophyseal adenoma, and gonadal tumours. Genetic alterations are often missed under routine genetic testing. Pathogenic variants in PRKAR1A are identified in most cases, while large exonic or chromosomal deletions have only been reported in a few cases. Our aim was to identify the causal genetic alteration in our kindred with a clinical diagnosis of CNC and prove its pathogenic role by functional investigation. Targeted testing of PRKAR1A gene, whole exome and whole genome sequencing (WGS) were performed in the proband, one clinically affected and one unaffected relative. WGS identified a novel, large, 10,662 bp (10.6 kbp; LRG_514t1:c.-10403_-7 + 265del; hg19, chr17:g.66498293_66508954del) deletion in the promoter of PRKAR1A in heterozygous form in the affected family members. The exact breakpoints and the increased enzyme activity in deletion carriers compared to wild type carrier were proved. Segregation analysis and functional evaluation of PKA activity confirmed the pathogenic role of this alteration. A novel deletion upstream of the PRKAR1A gene was proved to be the cause of CNC. Our study underlines the need for WGS in molecular genetic testing of patients with monogenic disorders where conventional genetic analysis fails.

CTNNB1 and APC Mutations in Sinonasal Myxoma : Expanding the Spectrum of Tumors Driven By WNT/ß-catenin Pathway.

Sinonasal myxoma (SNM) is a rare, benign mesenchymal neoplasm with distinct clinicopathologic features and aberrant nuclear localization of ß-catenin by immunohistochemistry. The molecular underpinnings have been linked to that of a "myxoid variant" of desmoid fibromatosis. Herein, we describe a series of 8 cases of SNM and propose clinical and biologic differences compared with desmoid fibromatosis. Our patient cohort is comprised of 5 males and 3 females (age range: 10 mo to 12 y), 6 of whom are aged less than or equal to 24 months. All presented with facial swelling, reflecting lesions involving the maxillary bone, and all underwent resection. All tumors were variably cellular and comprised of bland spindled to stellate cells in a profusely myxoid background with diffuse nuclear ß-catenin expression. All cases of SNM were analyzed by next-generation sequencing using the Oncopanel assay. Three cases failed sequencing, 2 of 5 successful cases exhibited exon 3 CTNNB1 alterations involving the ubiquitin recognition motif, and 3 had adenomatous polyposis coli ( APC ) deletions. One patient had APC germline testing which was negative. No germline testing was available for the remaining 7 patients. Follow-up data over a range of 1 month to 23 years was available for 7 of the 8 SNMs. One case patient had local recurrence, and all were alive without evidence of disease. This is in contrast to the high recurrence rate typically seen in desmoid fibromatosis, particularly after resection. Our findings expand the spectrum of tumors with underlying WNT/ß-catenin pathway and highlight the histologic, clinical, and genetic differences of SNM compared with desmoid fibromatosis. APC deletion raises the possibility of underlying germline alteration and familial adenomatous polyposis.

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.

A case report and literature review of Carney complex with atrial adenomyxoma.

BACKGROUND: Carney complex (CNC) is a rare multiple endocrine neoplasia syndrome characterized by mucocutaneous lentigines/ blue nevi, cardiac myxoma and endocrine overactivity. Here, we report a CNC case with PRKAR1A gene mutation characterized by left atrial adenomyxoma to explore the diagnosis and treatment of CNC. CASE PRESENTATION: A 42-year-old woman with a history of cardiac tumour surgery presented with typical features of Cushing syndrome, including central obesity, buffalo hump, mild facial plethora, purple striae on the lower abdomen, and spotty skin pigmentation. Left atrial adenomyxoma and thyroid papillary carcinoma were identified by postoperative histologic assays. Genetic screening revealed a pathogenic germline heterozygous mutation of c.682C > T (p.R228X) in exon 7 of the PRKAR1A gene. The clinical features and normal ACTH levels suggest this patient suffered the ACTH-independent primary pigmented nodular adrenocortical disease (PPNAD) with cyclic hypercortisolism or ACTH-dependent Cushing syndrome. CONCLUSION: CNC is uncommon, however, if a patient develops clinical features involving multiple endocrine and non-endocrine tumors, especially Cushing syndrome and cardiac myxoma, CNC should be considered. Genetic analysis is recommended in patients with suspected CNC.

Recurrent multi-cameral cardiac myxomas in a child with Carney complex.

Cardiac myxoma is a relatively rare tumour, usually solitary, that occurs primarily in the left atrium of adults, but comprises only 30% of cardiac tumours in children. We recently treated a 12-year-old girl with multiple recurrent myxomas in three cardiac chambers(following surgical resection 3 years earlier). Genomic analysis showed the PKAR1A mutation typical for Carney complex.

Somatic Mutation of PRKAR1A in Four Cases of Sporadic Cardiac Myxoma.

BACKGROUND: Inactivating mutations of the protein kinase A regulatory subunit 1 alpha (PRKAR1A) gene have been reported in familial cardiac myxoma. However, the role of PRKAR1A mutation in sporadic cardiac myxoma remains unknown. METHODS: Targeted next-generation sequencing (NGS) was performed to identify mutations with the PRKAR1A gene in seven cases of sporadic cardiac myxomas. Sanger sequencing of DNA from cardiac myxoma specimens and matched peripheral blood samples was performed to verify the identified mutations. RESULTS: Targeted NGS of myxoma DNA revealed 232 single nucleotide variants in 141 genes and 38 insertion-deletion mutations in 13 genes. Six PRKAR1A mutations were identified in four of the seven cardiac myxoma cases, and thus, the PRKAR1A inactivating mutation rate was 57.2% (4/7, 95% CI=0.44-0.58, P<0.05). The PRKAR1A variants identified by Sanger sequencing analysis were consistent with those from the NGS analysis for the four myxoma specimens. All of the pathogenic PRKAR1A mutations led to premature termination of PRKAR1A, except for one synonymous mutation. Moreover, none of the nonsense and missense mutations found in the myxoma specimens were found in the matched peripheral blood samples. CONCLUSION: Pathogenic mutations of the PRKAR1A gene were identified in tumor specimens from four cases of sporadic cardiac myxoma, and the absence of these mutations in peripheral blood samples demonstrated that they were somatic mutations.

Unusual Findings in a Patient With Carney Complex due to a Novel PRKAR1A Mutation.

BACKGROUND/AIM: Carney complex (CNC) is a rare autosomal dominant tumor-predisposition syndrome with variable expression. Its main features are pigmentary skin lesions, soft-tissue myxomas, and endocrine overactivity or tumors. There is occasional overlap with other syndromes, and oligosymptomatic cases may escape diagnosis. This report describes the long journey of a patient until the diagnosis of CNC was finally made after a thorough diagnostic workup. CASE REPORT: The female patient was referred for treatment of a subcutaneous tumor of the lower abdomen. Medical reports detailed previous excisions of fibroma, neurofibroma and myxoma, and a malignant tumor of the cerebellopontine angle. The resected subcutaneous tumor was a myxoma. The identification of a previously unknown frameshift mutation in the gene for protein kinase cAMP-dependent type I regulatory subunit alpha (PRKAR1A) in the patient confirmed the diagnosis of CNC. CONCLUSION: Patients with CNC may have highly variable clinical findings. Some rare lesions in CNC are more commonly recorded in other syndromes, making early diagnosis difficult in some cases. Genetic testing greatly facilitates diagnosis.

Fusion of High Mobility Group AT-hook 2 Gene (HMGA2) With the Chromosome 12 Open Reading Frame 42 Gene (C12orf42) in an Aggressive Angiomyxoma With del(12)(q14q23) as the Sole Cytogenetic Anomaly.

BACKGROUND/AIM: Aggressive angiomyxomas are mostly found in the pelvic and perineal region and are prone to recur after surgery. Cytogenetic information is available on only nine such tumors. Herein, we report the cytogenetic anomaly and its molecular consequence in another aggressive angiomyxoma. MATERIALS AND METHODS: An aggressive angiomyxoma found in a 33-year-old woman was examined using cytogenetic, RNA sequencing, reverse transcription polymerase chain reaction (RT-PCR), and Sanger sequencing techniques. RESULTS: The karyotype of short-term cultured tumor cells was 46,XX,del(12) (q14q23)[9]/46,XX[2]. RNA sequencing detected fusion of the high mobility group AT-hook 2 gene (HMGA2) with the chromosome 12 open reading frame 42 gene (C12orf42). RT-PCR together with Sanger sequencing verified the presence of an HMGA2::C12orf42 fusion transcript. CONCLUSION: The present case carrying del(12)(q14q23) and an HMGA2::C12orf42 chimeric transcript strengthens the notion that involvement of HMGA2 and its misexpression are pathogenetically important in the development of aggressive angiomyxomas.

Steroidogenic Factor-1 Lineage Origin of Skin Lesions in Carney Complex Syndrome.

Carney complex is a rare familial multineoplastic syndrome predisposing to endocrine and nonendocrine tumors due to inactivating mutations of PRKAR1A, leading to perturbations of the cAMP‒protein kinase A signaling pathway. Skin lesions are the most common manifestation of Carney complex, including lentigines, blue nevi, and cutaneous myxomas in unusual locations such as oral and genital mucosa. Unlike endocrine disorders, the pathogenesis of skin lesions remains unexplained. In this study, we show that embryonic invalidation of the Prkar1a gene in steroidogenic factor-1‒expressing cells leads to the development of familial skin pigmentation alterations, reminiscent of those in patients with Carney complex. Immunohistological and molecular analyses, coupled with genetic monitoring of recombinant cell lineages in mouse skin, suggest that familial lentiginosis and myxomas occur in skin areas specifically enriched in dermal melanocytes. In lentigines- and blue nevi‒prone areas from mutant mice and patients, Prkar1a/PRKAR1A invalidation occurs in a subset of dermal fibroblasts capable of inducing, under the influence of protein kinase A signaling, the production of promelanogenic EDN3 and hepatocyte GF signals. Our model strongly suggests that the origin of the typical Carney complex cutaneous lesions is the result of noncell-autonomous promelanogenic activity of a dermal fibroblast population sharing a community of origin with steroidogenic factor-1 lineage.

miRNAs in Cardiac Myxoma: New Pathologic Findings for Potential Therapeutic Opportunities.

MicroRNAs (miRNAs) regulate gene expression at the post-transcriptional level, contributing to all major cellular processes. The importance of miRNAs in cardiac development, heart function, and valvular heart disease has been shown in recent years, and aberrant expression of miRNA has been reported in various malignancies, such as gastric cancer and breast cancer. Different from other fields of investigation, the role of miRNAs in cardiac tumors still remains difficult to interpret due to the scarcity publications and a lack of narrative focus on this topic. In this article, we summarize the available evidence on miRNAs and cardiac myxomas and propose new pathways for future research. miRNAs play a part in modifying the expression of cardiac transcription factors (miR-335-5p), increasing cell cycle trigger factors (miR-126-3p), interfering with ceramide synthesis (miR-320a), inducing apoptosis (miR-634 and miR-122), suppressing production of interleukins (miR-217), and reducing cell proliferation (miR-218). As such, they have complex and interconnected roles. At present, the study of the complete mechanistic control of miRNA remains a crucial issue, as proper understanding of signaling pathways is essential for the forecasting of therapeutic implications. Other types of cardiac tumors still lack adequate investigation with regard to miRNA. Further research should aim at investigating the causal relationship between different miRNAs and cell overgrowth, considering both myxoma and other histological types of cardiac tumors. We hope that this review will help in understanding this fascinating molecular approach.

A novel 8.57-kb deletion of the upstream region of PRKAR1A in a family with Carney complex.

Carney complex (CNC) is a rare hereditary syndrome that involves endocrine dysfunction and the development of various types of tumors. Chromosome 2p16 and PRKAR1A on chromosome 17 are known susceptibility loci for CNC. Here we report a mother and son with CNC caused by an 8.57-kb deletion involving the transcription start site and non-coding exon 1 of PRKAR1A. The proband is a 28-year-old male with bilateral large-cell calcified Sertoli cell testicular tumors and pituitary adenoma. Comprehensive genomic profiling for cancer mutations using Foundation One CDx failed to detect any mutations in PRKAR1A in DNA from the testicular tumor. Single-nucleotide polymorphism array analysis of the proband's genomic DNA revealed a large deletion in the 5' region of PRKAR1A. Genomic walking further delineated the region an 8.57-kb deletion. A 1.68-kb DNA fragment encompassed by the deleted region showed strong promoter activity in a NanoLuc luciferase reporter assay. The patient's mother, who is suffering from recurrent cardiac myxoma, a critical sign for CNC, carried an identical deletion. The 8.57-kb deleted region is a novel lesion for CNC and will facilitate molecular diagnosis of the disease.

Diagnosis of Carney complex following multiple recurrent cardiac myxomas.

Carney complex is a rare syndrome caused by a genetic mutation leading to multiple endocrine abnormalities and a variety of tumors. Here, we report a case of Carney complex diagnosed due to recurrent multiple myxomas in the right atrium of a patient 16 years after the resection of the primary left atrial myxoma. Surgical excision was performed for the multiple recurrent right atrial tumors under cardiopulmonary bypass. The patient remained complication-free after surgery and was discharged on the 14th day. He was scheduled to continue echocardiographic follow-up and periodic systemic review by an endocrinologist. This case emphasizes the fact that if cardiac myxomas tend to be multiple and recurrent at a relatively young age, the possibility of Carney complex should be considered, even in the absence of any other related feature other than cardiac tumors.

Sporadic superficial angiomyxomas demonstrate loss of PRKAR1A expression.

Superficial angiomyxomas are cutaneous mesenchymal tumours that typically present clinically as slow-growing, solitary, asymptomatic nodules that can occur at any age. Histopathologically, these dermal and subcutaneous tumours are characterized by abundant myxoid stroma, numerous thin-walled and often arbourising blood vessels, and spindled to stellate fibroblast-like cells. While usually sporadic, superficial angiomyxomas can occasionally be associated with Carney complex (CNC), an autosomal dominant disorder characterized by inactivating germline mutations in the 1-alpha regulatory subunit of protein kinase A (PRKAR1A) and various clinical manifestations, including cardiac myxomas, facial lentigines, epithelioid blue naevi, endocrinopathies and psammomatous melanotic schwannomas. In this study, we sought to characterize the presence or absence of PRKAR1A expression by immunohistochemistry (IHC) in sporadic superficial angiomyxomas based on our observations in an index case. In total, PRKAR1A immunohistochemical expression was determined in 15 sporadic superficial angiomyxoma cases retrieved from the surgical pathology archives. IHC demonstrated that the lesional cells in 12 cases (80%) were non-reactive to antibodies against PRKAR1A. This study provides evidence in support of a role for PRKAR1A in the development of clinically non-syndromic superficial angiomyxomas. Together with previous studies, this report demonstrates that PRKAR1A may play an important role in the development of a variety of myxomatous mesenchymal tumours.

Case Report: An Atypical Case of Carney Complex.

BACKGROUND Intracardiac tumors are a rare entity, with myxomas being the most common among them (approximately 50% of intracardiac tumors). Up to 80% of myxomas originate within the left atrium and while most are incidental or isolated findings in asymptomatic patients, others may result in clinical manifestations of heart failure or emboli. Moreover, in some cases, myxomas can be part of a genetically inherited syndrome known as Carney complex (CNC), and present with varied phenotypes, including skin, endocrine, and neuroendocrine tumors. CASE REPORT We present a case of a 54-year-old male patient who presented with a several-month history of non-specific cough, dyspnea on exertion, and palpitations along with several skin tags, nevi, and nodules. He was found to have a retrocardiac density on chest X-ray, which was revealed to be a large left atrial myxoma on echocardiography. The myxoma was surgically excised and genetic testing for a mutation of the PRKAR1A gene (the most common mutation underlying CNC) was negative. However, 2 major clinical criteria for diagnosis of CNC were fulfilled based on cardiac myxoma and spotty skin pigmentation. In this report, we focus on the clinical manifestations of CNC, including guidance on tumor surveillance and genetic variants of CNC. CONCLUSIONS While CNC is most commonly associated with an inactivating mutation of the PRKAR1A gene, it can be diagnosed clinically in the absence of an identifiable genetic mutation. In patients presenting with atypical cardiac tumors, the early recognition of cutaneous manifestations can raise the index of suspicion for CNC, which can facilitate early diagnosis, treatment, and initiation of surveillance for neoplasia development.

A novel mutation in PRKAR1A gene in a patient with Carney complex presenting with pituitary macroadenoma, acromegaly, Cushing's syndrome and recurrent atrial myxoma

SUMMARY Carney complex (CNC) is a rare syndrome of multiple endocrine and non-endocrine tumors. In this paper we present a 23-year-old Iranian woman with CNC who harbored a novel mutation (c.642dupT) in PRKAR1A gene. This patient presented with pituitary macroadenoma, acromegaly, recurrent atrial myxoma, Cushing's syndrome secondary to primary pigmented nodular adrenocortical disease and pigmented schwanoma of the skin. PRKAR1A gene was PCR amplified using genomic DNA and analyzed for sequence variants which revealed the novel mutation resulting in substitution of amino acid cysteine instead of the naturally occurring valine in the peptide chain and a premature stop codon at position 18 (V215CfsX18). This change leads to development of tumors in different organs due to lack of tumor suppressive activity secondary to failure of synthesis of the related protein.

A novel mutation in PRKAR1A gene in a patient with Carney complex presenting with pituitary macroadenoma, acromegaly, Cushing's syndrome and recurrent atrial myxoma.

Carney complex (CNC) is a rare syndrome of multiple endocrine and non-endocrine tumors. In this paper we present a 23-year-old Iranian woman with CNC who harbored a novel mutation (c.642dupT) in PRKAR1A gene. This patient presented with pituitary macroadenoma, acromegaly, recurrent atrial myxoma, Cushing's syndrome secondary to primary pigmented nodular adrenocortical disease and pigmented schwanoma of the skin. PRKAR1A gene was PCR amplified using genomic DNA and analyzed for sequence variants which revealed the novel mutation resulting in substitution of amino acid cysteine instead of the naturally occurring valine in the peptide chain and a premature stop codon at position 18 (V215CfsX18). This change leads to development of tumors in different organs due to lack of tumor suppressive activity secondary to failure of synthesis of the related protein.