1 SUBMITTED 10 JAN 23 1 REVISION REQ. 23 MAR 23; REVISION RECD. 30 MAR 23 2 ACCEPTED 3 MAY 23 3 ONLINE-FIRST: MAY 2023 4 DOI: https://doi.org/10.18295/squmj.5.2023.037 5 6 Congenital Blood Cyst of a Child 7 A Case Report and Review of Literature 8 *Rachid Kaddoura,1 Issam El Rassi,2 Zainab Al Awadi,2 9 Mohamed Kasem2 10 11 1College of Medicine, Mohammed Bin Rashid University of Medicine and Health 12 Sciences, Dubai, United Arab Emirates; 2Al Jalila Children's Speciality Hospital, United 13 Arab Emirates. 14 *Corresponding Author’s e-mail: rachid.kaddoura@students.mbru.ac.ae 15 16 Abstract 17 Blood-filled cysts of the heart valves are frequently reported at postpartum autopsies of 18 infants. They are seen as round nodules mostly in the paediatric age group in infants less 19 than two months of age and disappear spontaneously within six months of life. We 20 present a unique case of an 11-month-old girl with a blood-filled cyst on the posterior 21 leaflet of the pulmonary valve that was successfully treated. This case report highlights 22 the characteristics and course of a paediatric patient with blood-filled cysts. Further 23 studies are yet needed to better understand the diagnostic approaches to blood-filled cysts 24 as well as treatment modalities to fill the gap in clinical settings. 25 Keywords: Blood filled cysts; Pulmonary valve; Pulmonary artery; Paediatrics; Cardiac 26 tumor; Cardiology. 27 28 2 Introduction 29 Blood-filled cysts (BFCs) are rare benign tumors mainly reported as cardiac tumors.1 30 Since primary cardiac valve tumors are very uncommon, autopsy studies have provided 31 much of the current detailed information available in the literature.2, 3 Numerous 32 parameters, such as tumor classification, location size, growth rate, and susceptibility to 33 embolize, affect the overall clinical presentation. Both myxomas and papillary 34 fibroelastomas are the pathological conditions most likely to be related to embolism, with 35 the latter making up most primary valve tumor types.3, 4 Moreover, lipomas, myxomas, 36 and rhabdomyomas are all reported as primary cardiac tumors as well. 37 38 BFCs of the heart valves were first reported in 1844 by Elsasser.5 BFCs are often found 39 on the atrioventricular valves of newborn infants’ necropsies. They are usually seen as 40 small, rounded, multiple nodules on the atrial surfaces of the atrioventricular valves, but 41 are also seen less often on the ventricular surfaces of the semilunar valves.1-3 In this 42 report we present a rare case of a paediatric patient with a BFC on the pulmonary valve 43 leaflet. 44 45 Case Report 46 An 11-month-old girl presented to her general paediatrician for a non-cardiac cause at the 47 beginning of the year 2022. She was noted to have a loud systolic heart murmur in the 48 pulmonary area. The child was otherwise well, had no previous history of infections, and 49 has normal clinical examination findings otherwise. 50 51 The echocardiogram demonstrated severe right ventricular outflow obstruction due to a 52 possible cyst on the posterior leaflet of the pulmonary valve. The valve itself looked 53 normal, and there was post-stenotic dilatation of the main pulmonary artery. The gradient 54 across the pulmonary valve was 65 mmHg peak. 55 56 The patient underwent a right heart catheterization. The angiogram showed a cyst fixed 57 on the surface of one of the pulmonary valve leaflets (Figure 1). The cyst was mobile 58 with the leaflet, but not causing any regurgitation. No ballooning was done, and the 59 3 patient had a chest CT scan which showed a filling defect in the main pulmonary artery. 60 The CT scan showed normal distal pulmonary arteries and branches, as well as normal 61 lung parenchyma, mediastinum, and no lymphadenopathy. A comprehensive infectious 62 and immunological assessment showed no underlying disease. 63 64 Following the discussion with our multidisciplinary team (MDT), we decided to 65 surgically remove the cyst (Figure 2). The surgical procedure was uneventful. Resection 66 of the whole cyst that was attached to the posterior leaflet of the pulmonary valve was 67 performed, and the gradient decreased to less than 15 mmHg, with moderate pulmonary 68 valve regurgitation. 69 70 The histopathology of the cyst (Figure 3) showed a 1*0.5*0.3cm multiloculated cyst, 71 filled with blood, and composed of a thin fibrous wall with focal myxoid changes. The 72 child made full recovery. At age of three, only a 12-mmHg peak gradient at the 73 pulmonary valve was observed, with moderate regurgitation, and no new cysts were 74 noted on any of the heart valves. 75 76 Informed and written consent for the patient’s procedure and publication purposes for this 77 case report was obtained from the parents. 78 79 Discussion 80 This report presents a unique case of a paediatric patient with a BFC on the posterior 81 leaflet of the pulmonary valve that was successfully managed and treated. Unlike the 82 paediatric age group, singular valvular BFCs are rarely reported in older children and 83 adults, this is attributed to the fact that the cysts spontaneously regress in most patients as 84 they age.6 Liese et al., Cumming and Ferguson and Sakakibara et al., Pa§aoglu et al., and 85 Minato et al. reported 12 BFCs of the pulmonary valve that were treated successfully by 86 surgical resection.5-12 87 88 BFCs presents with symptoms of severe valvular stenosis due to the outflow obstruction, 89 as well as regurgitation presenting with signs of cyanosis, although they have mostly 90 4 been reported to be asymptomatic and only discovered incidentally usually on CT scans 91 done for non-cardiac reasons, especially in the infant age group.6,12 The patient presented 92 in this case report, initially went to the general paediatrician (GP) with no cardiac 93 symptoms, and the leading cause of the BFCs discovery was due to a loud systolic 94 murmur detected by the GP. Following that, she was referred to the cardiology 95 department and an echocardiogram was done which identified the BFC. Echocardiogram 96 is considered to be the gold standard for the diagnosis of BFCs, and in rare cases where a 97 thrombus or bacterial vegetations are suspected, contrast echocardiogram might help 98 differentiate it from cardiac cysts.13 99 100 To date, it is still unknown where the source of BFCs in cardiac valves arise from. 101 Several animal studies revealed that 20% of all animal hearts contained BFCs, 102 highlighting its high prevalence.14 Regarding the development of BFCs, adult cases have 103 been attributed to blunt trauma to the chest and complications during valvular surgeries, 104 however, their cause in the paediatric age group is still unknown.13 Tsutsui et al. 105 suggested that BFCs may originate during the development of valves in early 106 embryogenesis or during early period of life from blood entrapped in valvular crevices or 107 tiny invaginations during development, therefore, a neonate with normal echocardiogram 108 findings can still develop BFCs in early infancy or childhood, while this process is very 109 unlikely to occur at later stages during adulthood.15 Another hypothesis suggests that 110 BFCs are primarily due to hematoma formation as a result of blocked small vessels.12 111 Furthermore, based on the findings of the histological and ultrastructural analysis, BFCs 112 could be due to the expansion of thin-walled valvular arteries in response to mechanical 113 stress caused by the pressure gradient when atrioventricular valves are closed, developing 114 a cyst.14 However, the presence of BFCs in low-pressure structures like the pulmonary 115 valve cannot be explained by the mentioned theory. Therefore, the mentioned hypotheses 116 are quite hard to confirm and the definite formation of a BFC is not yet well established 117 in the current literature. 118 119 In terms of management, Paşaoğlu et al. suggested surgically removing the BFCs in the 120 heart at the time of diagnosis independent of the patient’s symptoms.10 This was the 121 5 course of action for the patient presented in this case report. On the other hand, Dencker 122 et al. encouraged a more conservative approach in asymptomatic patients and stated that 123 surgical approaches should be kept for symptomatic patients or if the cyst leads to cardiac 124 dysfunction.13 Surgical interventions are usually done in order to rule out malignancy and 125 risk of strokes. Pharmacological therapies including anticoagulants and beta-blocker use 126 are still controversial with very little evidence available in the current literature.13 This 127 emphasizes the need for more research exploring the outcomes of different management 128 approaches. 129 130 Conclusion 131 In summary, we have reported a rare case of BFC above the pulmonary valve in addition 132 to a literature review. Although several theories have been postulated regarding the origin 133 of BFCs, it remains unknown. BFCs are rare and are seen as small round nodules on 134 imaging modalities. However, a better understanding of the diagnostic approaches to 135 BFCs as well as treatment modalities is required to ensure an overall better prognosis in 136 both the adult and paediatric age groups. 137 138 Conflicts of Interest 139 The authors declare no conflict of interests. 140 141 Author Contributions 142 RK, IER and MK conceptualized and designed the work. 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