Canadian Association of Pathologists - Case of the Month, January 2007
53 year-old man with left arm weakness.
Diagnosis:
Left atrial myoxma.
Myxomas are the most common primary, benign, intracardiac neoplasm, accounting for approximately 40% of all cardiac tumours and usually arising from the intraatrial septum (left 3 times more common than right). They are often lobulated, gelatinous masses that protrude through the atrioventricular valve orifice, damaging the valve cusps, with this trauma leading to hemorrhage into the neoplasm.
Microscopically, these tumours are characterized by distinctive stellate or polygonal cells embedded in an abundant mucopolysaccharide-rich stroma.
Variable degrees of hemorrhage, calcification, thrombus or inflammation may be present. Mitoses are typically absent.
Significant factoids:
• Note should be made of the adequacy of surgical excision by commenting on the tumour margins (on gross and histology) at the base.
• These are benign neoplasms. Metastases do not occur. However, the soft, gelatinous neoplasm can break off and embolise. The embolic event (to the CNS or to the periphery) may lead to the patient’s clinical presentation, as in this case.
Ref.
Butany J, El Demellawy D, Collins MJ, Israel NSh, Graba J, David TE. A large left atrial myxoma. J Card Surg. 2004 Nov-Dec; 19(6):547-51
Swartz MF, Lutz CJ, Chandan VS, Landas S, Fink GW. Atrial myxomas: pathologic types, tumor location, and presenting symptoms. J Card Surg. 2006 Jul-Aug;21(4):435-40