View source for Cystic tumour of the atrioventricular nodal region

{{ Infobox diagnosis
| Name       = {{PAGENAME}}
| Image      = Cystic tumour of the atrioventricular nodal region - very low mag.jpg
| Width      =
| Caption    = Cystic tumour of the atrioventricular nodal region. [[H&E stain]].
| Synonyms   = cystic tumour of the atrioventricular node
| Micro      = cystic spaces lined by single layer of bland epithelial cells, +/-focal mononuclear inflammation, +/-[[psammoma bodies]] 
| Subtypes   =
| LMDDx      = cystic metastatic [[carcinoma]]
| Stains     =
| IHC        = CEA +ve, EMA +ve
| EM         =
| Molecular  =
| IF         =
| Gross      = very small cysts in region of [[AV node]]
| Grossing   = see ''[[Heart#Conducting_system|conducting system of heart]]''
| Staging    =
| Site       = [[heart]] - see ''[[cardiac tumours]]''
| Assdx      =
| Syndromes  =
| Clinicalhx = [[sudden cardiac death]]
| Signs      =
| Symptoms   =
| Prevalence = very rare
| Bloodwork  =
| Rads       =
| Endoscopy  =
| Prognosis  = good if caught in time
| Other      =
| ClinDDx    =
| Tx         = excision
}}
'''Cystic tumour of the atrioventricular nodal region''', abbreviated '''CTAVNR''', is a rare cardiac tumour that can lead to [[sudden cardiac death]].

It is also known as '''cystic tumour of the atrioventricular node'''. 

''Benign mesothelioma of the atrioventricular node'' is also used; however, these tumours are not ''[[mesothelioma]]s''.<ref name=pmid16254122>{{Cite journal  | last1 = Evans | first1 = CA. | last2 = Suvarna | first2 = SK. | title = Cystic atrioventricular node tumour: not a mesothelioma. | journal = J Clin Pathol | volume = 58 | issue = 11 | pages = 1232 | month = Nov | year = 2005 | doi =  | PMID = 16254122 }}</ref>

==General==
*Super rare.<ref name=pmid11855098>{{Cite journal  | last1 = Kaminishi | first1 = Y. | last2 = Watanabe | first2 = Y. | last3 = Nakata | first3 = H. | last4 = Shimokama | first4 = T. | last5 = Jikuya | first5 = T. | title = Cystic tumor of the atrioventricular nodal region. | journal = Jpn J Thorac Cardiovasc Surg | volume = 50 | issue = 1 | pages = 37-9 | month = Jan | year = 2002 | doi =  | PMID = 11855098 }}</ref>
*Usually 1-2 mm.
*May cause [[Sudden_natural_death|sudden cardiac death]].<ref name=pmid10722558/>
*Antemortem diagnosis in case reports; only four reported in literature as of 2010.<ref name=pmid19144541>{{Cite journal  | last1 = Sharma | first1 = G. | last2 = Linden | first2 = MD. | last3 = Schultz | first3 = DS. | last4 = Inamdar | first4 = KV. | title = Cystic tumor of the atrioventricular node: an unexpected finding in an explanted heart. | journal = Cardiovasc Pathol | volume = 19 | issue = 3 | pages = e75-8 | month =  | year =  | doi = 10.1016/j.carpath.2008.10.011 | PMID = 19144541 }}</ref>

==Gross==
*"Bump" in the ''triangle of Koch''.
*Cystic spaces.

==Microscopic==
Features:<ref name=pmid10722558>{{Cite journal  | last1 = Paniagua | first1 = JR. | last2 = Sadaba | first2 = JR. | last3 = Davidson | first3 = LA. | last4 = Munsch | first4 = CM. | title = Cystic tumour of the atrioventricular nodal region: report of a case successfully treated with surgery. | journal = Heart | volume = 83 | issue = 4 | pages = E6 | month = Apr | year = 2000 | doi =  | PMID = 10722558 }}</ref>
*Cystic spaces lined with single layer of epithelial cells.
*+/-Focal mononuclear inflammation.
*+/-[[Psammoma bodies]]. 

DDx:
*Cystic [[metastatic carcinoma]].

===Images===
<gallery>
Image:Cystic_tumour_of_the_atrioventricular_nodal_region_-_very_low_mag.jpg | CTAVNR - very low mag. (WC)
Image:Cystic_tumour_of_the_atrioventricular_nodal_region_-_high_mag.jpg | CTAVNR - high mag. (WC)
</gallery>

==IHC==
Features:<ref name=pmid16254122/>
*CEA +ve.
*[[EMA]] +ve.
*[[CK7]] +ve.
*Calretinin -ve.
*WT1 -ve.

==See also==
*[[Cardiac tumours]].
*[[Cardiac arrhythmias]].
*[[AV node]].

==References==
{{Reflist|1}}

[[Category:Diagnosis]]
[[Category:Cardiac tumours]]