Atrio-Ventricular Nodal Tumor Associated with Polyendocrine Anomalies

Cystic Tumor of the Atrioventricular Node of the Heart Appears to Be the Heart Equivalent of the Solid Cell Nests (Ultimobranchial Rests) of the Thyroid

“…1,3,6 This might explain the cases of intracardiac thyroid tissue 45 and cases of coexistence of ectopic thyroid and CTAVN in the heart. 46 Congenital CTAVN can occur in patients with complex congenital heart disease, 47 thyroglossal duct cysts, 47 coexisting cysts in the ovaries and breast, 48 polycystic ovaries, 34 ventricular septal defect, 30 nasal septal defect, 47 Dandy-Walker anomaly, 30 encephalocele, 47 thinning of the corpus callosum, 47 absent septum pellucidum, 47 Meckel diverticulum, 30 hyperplasia of the islets of Langerhans, thymic hyperplasia, adrenal tissue heterotopia, clear cell adenomatosis in the kidney, 17 and/or Emery-Dreifuss muscular dystrophy. 22 Possible familial occurrence, 35 association with midline defects, and association with other congenital lesions suggest a genetic defect involving migration of embryologic tissues in patients with CTAVN.…”

“…The CTAVN represents an ultimobranchial heterotopia, and its histogenesis is congruent with an alteration in cardiac neural crest cell development. 12,15,16,22,23,28,32,33* + + + + TTF-1 3* -+ -+ Thyroglobulin 3,4,6,7,13,17 ,22,23* ----Calcitonin 2-4,6-8,17,23,28,32,36* -+ -+ Chromogranin 4,6,16,17,22,23* -+ -+ Synaptophysin * -+ -+ CEA 2,3,[6][7][8]11,[13][14][15][16][17]22,23,29,30,32,34…”

“…The cystic tumor of the atrioventricular node (CTAVN) is a benign cystic mass located at the base of the atrial septum of the heart, in the region of the atrioventricular node. [11][12][13][14][15][16][17][18][19][20][21] Microscopically, the CTAVN is composed of solid and/or cystic structures of epithelial cells with a second population of neuroendocrine cells numerically less conspicuous. [16][17][18]22,23 It is a clinicopathologic entity that can occur as an incidental finding at autopsy or produce syncope or sudden death associated with complete heart block.…”

“…[11][12][13][14][15][16][17][18][19][20][21] Microscopically, the CTAVN is composed of solid and/or cystic structures of epithelial cells with a second population of neuroendocrine cells numerically less conspicuous. [16][17][18]22,23 It is a clinicopathologic entity that can occur as an incidental finding at autopsy or produce syncope or sudden death associated with complete heart block. It has been dubbed as the "smallest human tumor which causes sudden death," 19 and almost all published cases were diagnosed at postmortem examination.…”

Complex Choristoma of the Gyrus Rectus

“…All except the last can be excluded readily based on location and histologic features. 1,2,4,5,9 Both are characterized by solid and microcystic squamoid structures, which are immunoreactive for CEA, cytokeratin 7, cytokeratin 903 and p63. Indeed, the apparently benign biologic behavior, low proliferative index, and well-differentiated histology suggest a heterotopia or choristoma rather than a neoplasm.…”